bluuebunny/crossref_metadata_2025 huggingface dataset:
Water Exchanges of Isolated Mammalian Tissues at Low Temperatures
Authors: Adolph E. F. , Richmond J.
Published: December 2017

Water exchanges of thin tissues from rats and ground squirrels were influenced by temperature, anoxia and storage. Kidney, liver, auricle and diaphragm were removed from precooled animals; kidney and liver were also sliced. Changes of tissue weights were measured with a torsion balance. At 6° or 16° tissues took up water from saline solution that was isotonic at 36°. Both warmth and oxygen were needed to resist this swelling, and the changes due to cold or anoxia or cyanide were reversible. Evidently water was expelled from the tissue, and probably from its cells, through a process dependent on oxidative metabolism and warmth. The reversal of swelling served as one test of tissue survival. Within an hour or two before immersion the control of water exchanges suffered no permanent damage from cold or anoxia, but over longer periods of time damage resulted.
Use of Electrical Currents to Delay Intravascular Thrombosis in Experimental Animals
Authors: Sawyer Philip N. , Deutch Bernhard
Published: December 2017

Previous studies on the relationship of electric phenomena to intravascular thrombosis have been discussed. On the basis of these studies, canine experiments were designed to determine whether or not a negatively charged electrode could by means of its oriented current prevent formation of a thrombus in an injured vessel. Using electrodes of several types a series of controlled experiments were performed which demonstrate that a current created by the technique used would delay intravascular thrombosis for periods up to 12 hours.
Renin Tachyphylaxis and Renal Ischemia in the Cat
Authors: Drury Douglas R. , Schapiro Shawn
Published: December 2017

The production of renin by the completely ischemic cat's kidney was investigated, as well as the relationship of renin to experimental hypertension in the cat. Tachyphylaxis to hog renin abolishes the pressor response following endogenous renin production by the completely ischemic kidney. However, the elevated blood pressure which occurs following partial renal ischemia (renal hypertension) is not reduced after renin tachyphylaxis. It is therefore concluded that the mechanism responsible for the elevation in blood pressure in the two cases is on a qualitatively different basis.
Rat Renal Tissue Water and Electrolyte Content in Simple Solutions in Vitro
Authors: Deyrup Ingrith
Published: December 2017

Tissue slices prepared from rat renal cortex, when incubated in simple solutions in vitro, show a capacity to regulate water content independently of the establishment of definite tissue levels of Na and K. Na may be lost, accompanying water, from hyperhydrated tissue without simultaneous reaccumulation of K. The capacity for parallel adjustment of water and Na content is impaired or lost following maintenance of the tissue at 37°C for 3.5–7 hours under anoxic conditions.
Discrimination of Calcium and Strontium by the Kidney
Authors: MacDonald N. S. , Noyes P. , Lorick P. C.
Published: December 2017

Skeletal retention and excretion of strontium were directly compared with those of calcium, by injecting solutions containing both radioisotopes, Ca45 and Sr90, into rats and rabbits. In normal animals, a greater fraction of the injected dose of Ca45 was retained in the skeleton than was observed for Sr90. In complementary fashion, the fraction of the injected Sr90 which appeared in the urine was greater than the fraction of the dose of Ca45 which was excreted. However, in rats which were actively calcifying tibial fractures, this difference disappeared. The enhanced accumulation of radioactivity in deposits of new bone possessed the same ratio of Sr90: Ca45 as the solution injected. Furthermore, when the functions of the kidneys of normal rabbits were impaired by poisoning with mercuric chloride or were completely extinguished by nephrectomy, again the usual differences in Ca45 and Sr90 deposition in bone tissue disappeared. When plasma containing both Ca45 and Sr90 was shaken with powdered bone, both radioisotopes were extracted in equivalent amounts. It was concluded that the avidity of bone tissue, per se, for strontium ions is not discernably different from that for calcium ions. The retention by the skeleton of a larger fraction of an injected quantity of calcium than of simultaneously administered strontium was attributed, in part, to a renal discrimination causing a greater relative loss of strontium to the urine.
Pituitary Growth Hormone and the Question of Pancreatic Secretion of Glucagon
Authors: Sirek Otakar V. , Sirek Anna , Best Charles H.
Published: December 2017

Experiments are presented in which normal dogs were injected with a highly purified growth hormone preparation. One hour later blood samples were drawn simultaneously from the pancreatico-duodenal and jugular veins. The ‘central’ and ‘peripheral’ blood samples were injected into depancreatized dogs. While the injection of ‘peripheral’ blood produced no appreciable change in the blood sugar level of the diabetic recipient, the ‘central’ blood caused a definite but transient rise in blood sugar. The rise could be prevented by treating the recipient diabetic animal with the adrenergic blocking agent dihydroergotamine. It has been concluded that the hyperglycemic factor present in the blood of the pancreatico-duodenal vein after injection of growth hormone preparations is not identical with glucagon-Lilly, the effect of which is not influenced by dihydroergotamine. In two experiments in which completely depancreatized, instead of intact, dogs were used as donors the administration of growth hormone produced the characteristic hyperglycemic response when ‘central’ blood samples were injected into other depancreatized dogs. These findings cast doubt on the pancreatic origin of the hyperglycemic material and add interest to the search for its source and nature. Further experiments using depancreatized dogs are in progress.
Interrelationship of Plasma Cholate and Phospholipid Concentrations and Their Resultant Effect on Plasma Cholesterol in Biliary Obstruction
Authors: Friedman Meyer , Byers Sanford
Published: December 2017

Elevation of plasma cholate (by intravenous injection of sodium cholate) in both the normal rat and the rat with biliary obstruction was found to lead to an elevation of plasma phospholipid and cholesterol. Experimental elevation of plasma phospholipid (also by injection), however, while leading to an elevation of plasma cholesterol did not elevate the plasma cholate in either the normal or obstructed rat. Furthermore, comparison of the cholesterol-phospholipid ratio obtained in rats by infusion of phosphatide with those observed in rats with biliary obstruction suggests that the plasma phospholipid elevation occurring spontaneously in these latter rats induced the hypercholesteremia observed. In view of these observations, it is suggested the elevation of plasma bile acid occurring in biliary obstruction effects its hypercholesteremic effect by first leading to the elevation of plasma phospholipid. The latter in turn leads to the hypercholesteremia observed.
Volume of Rabbit and Rat Renal Cortical Slices Permeable to P-Aminohippurate (PAH), Diodrast and Urokon
Authors: McIntosh B. J. , Childress C. C.
Published: December 2017

A method is presented which allows one to measure the permeable volume of the renal cortex to substances which are transported or actively accumulated by the renal cortex. This permeable volume in rat and rabbit renal cortical slices has been measured using PAH, Diodrast and Urokon as the transported substances. It is less than the volume of tissue water. Therefore, a volume of the renal cortex must be impermeable to these substances. It is postulated that all or part of the impermeable volume is made up of the tubular cells. The permeable volumes are 0.474 cc/gm tissue for PAH, 0.542 cc/gm tissue for Diodrast, and 0.447 cc/gm tissue for Urokon, as compared to 0.771 cc/gm for the tissue water. The active accumulation of these substances by rabbit renal cortical slices after 90– 130 minutes is 10.10 µm/gm for PAH, after 90 minutes is 1.90 µm/gm for Diodrast, and after 60–150 minutes is 3.20–3.53 µm/gm for Urokon.
Effect of Changes in Ambient Temperature on Spontaneous Activity, Food Intake and Body Weight of Goldthioglucose-Obese and Nonobese Mice
Authors: Fregly M. J. , Marshall N. B. , Mayer J.
Published: December 2017

Goldthioglucose-obese mice cannot adjust their food intake to meet the increased energy requirements due to cold. At all ambient temperatures above 15°C the spontaneous running activity of these animals is less than that observed for nonobese controls. Activity of obese mice is maximal at 19°C and minimal at 15°C or lower. Body weights decrease during exposure to cold. In contrast to that of obese mice, running activity of nonobese controls is maximal at an ambient temperature of 25°C but nearly ceases at 15°C or lower. The food intake of these animals increases in the cold and remains elevated even at temperatures at which activity decreases. The body weight of nonobese controls is either maintained constant or increases during exposure to cold air.
Hypoglycemic Effect of High Environmental Temperature on Dogs
Authors: Kanter G. S.
Published: December 2017

Exposure of unanesthetized dogs to high environmental temperature (120°F) and low humidity (< 20%) for 4 hours with no water available for drinking, results in a fall in both whole blood and plasma glucose concentration in spite of the dehydration which also occurs. In one group of dogs so tested the whole blood glucose fell 22%, in another group it fell 16%. The average dehydration was –6% body weight. One would expect such a concomitant dehydration to cause an increase in glucose concentration, much as has been reported in man. Under the experimental conditions imposed, a hypoglycemia resulted in dogs. The hypoglycemia is apparently associated with high temperature for when the animals were exposed to heat the glucose fell and the rectal temperature increased, when they were removed from heat and allowed to recover, the rectal temperature fell and the glucose returned towards normal. The fall in glucose is metabolic in nature for no evidence of any glycosuria was found.
Effect of Hypothermia of 2 to 24 Hours on Oxygen Consumption and Cardiac Output in the Dog
Authors: Fisher Bernard , Russ Clem , Fedor E. J.
Published: December 2017

The changes occurring in cardiac output and oxygen consumption in short periods of hypothermia are the same when either ether or pentobarbital sodium is used as the anesthetic agent during the induction of hypothermia. Following an initial decrease in oxygen consumption, no further change occurred as long as the body temperature was maintained at a constant level. Cardiac output, arterial-venous oxygen difference, and coefficient of oxygen utilization remain unchanged for longer periods of time than most physiologic parameters studied during prolonged hypothermia at constant temperatures. After about 14 hours they also begin to alter so that by 24 hours the changes are profound. Stagnant anoxemia and marked increased in the coefficient of O2 utilization resulting from the markedly lowered cardiac output, which was 5% of the precooled controls, occurred.
Oxygen Consumption of the Auricles, Right and Left Ventricles of the Normal, Hypothyroid and Hyperthyroid Rat Heart
Authors: Goh Kong-oo , Dallam R. Duncan
Published: December 2017

A study of the oxygen consumption of the atrium, right and left ventricles from rat heart has been reported. The response of these heart regions to the in vitro and in vivo addition of thyroxine has been reported. Results obtained were: a) The oxygen consumption of the left ventricle from normal animals was found to be about 25% greater than that of the right ventricle and atrium. b) In animals whose thyroid activity was depressed the oxygen consumption of the atrium and the right and left ventricles was proportionately decreased about 25%. c) Animals whose thyroid activity was increased were found to have an increased oxygen consumption in all areas of the heart, however, not proportionately. d) The in vitro addition of thyroxine to the three heart areas from animals with decreased thyroid activity and normal animals caused an increase in oxygen consumption, whereas it did not appreciably affect the oxygen consumption of the heart areas from animals with increased thyroid activity.
Modification of Radiation Response in Mice by Heterologous and Isologous Bone Marrow
Authors: Cole L. J. , Habermeyer J. G. , Nowell P. C.
Published: December 2017

A marrow transfer technique was used to study the functional state of the marrow of lethally x-irradiated mice after intravenous injection with isologous or heterologous (rat) marrow. In the former case, it was found that the marrow behaved as functionally active mouse marrow (in terms of radiation protection) at 19 days postradiation; while it was essentially inactive at 14 days although it appeared to be regenerated, as judged histologically. Irradiated mice (800 r) injected intravenously with rat marrow exhibited ‘regenerating’ marrow, but it was not active in preventing death when injected into other irradiated mice. Rat bone marrow, administered intraperitoneally to lethally x-irradiated mice failed to elicit any 15-day survivors, even with 350 mg or 700 mg doses, per mouse. This latter dose is 70 times greater than the 10 mg of isologous mouse marrow, required to evoke 50% survival.
Effect of Incubation With Rabbit Serum on Toxicity and Tumor-Necrotizing Action of Polysaccharide From S. marcescens
Authors: Kelly Margaret G. , Smith Norman H. , Rall David P.
Published: December 2017

Effect of incubation with rabbit serum on the lethality and tumor-necrotizing activity of two pyrogenic polysaccharide preparations was studied in mice carrying i.m. implants of sarcoma 37. The polysaccharide materials were isolated from the same strain of S. marcescens, but were prepared in different laboratories and obtained by different methods. One preparation was a crude, insoluble fraction containing protein, the other was a soluble, trypsin-digested material giving negative protein color tests. Incubation in serum reduced the lethality of the crude preparation by about 50%, but had no effect on the lethality of the more highly purified polysaccharide; it had no demonstrable effect, moreover, on the tumor-necrotizing activity of either preparation. Similar results were obtained with mice rendered tolerant by two injections of polysaccharide in saline. The factor in serum responsible for the decrease in toxicity of the crude preparation was stable to heating at 56°C for 30 minutes, but was inactivated by heating to 70°C for 8 minutes. Tumor implants exhibited apparent refractoriness to the tumor-necrotizing action of the polysaccharide preparations after 6 days growth in hosts rendered tolerant to the lethal action of the material before tumor implantation.
Crossed Reflexes of Cutaneous Origin
Authors: Perl Edward R.
Published: December 2017

Changes in excitability of spinal motorneurons produced by a volley of impulses in cutaneous nerves of the contralateral hindleg were studied in cats acutely made spinal or decerebrate. Motorneuron excitability was determined by measuring changes in electrical activity recorded from ventral roots or muscle nerves. Depending upon the size of fibers fired, at least two different effects were produced by synchronous impulses in crossed cutaneous nerves. When the cutaneous nerve activity was confined to the low threshold, rapidly conducting fibers, 14–6 µ in diameter, crossed knee and ankle flexor motorneurons were facilitated after a central latency of some 3 msec., and on occasion discharged. In several instances crossed extensor motorneurons were depressed during the course of flexor facilitation. When the cutaneous nerve activity involved the smaller (6–2 µ) myelinated fibers as well, prolonged inhibition of the crossed flexor motorneurons followed the initial facilitation and the crossed extensor motorneurons were facilitated, after a delay of 6–30 msec., for periods up to 300 msec.
Mechanisms of Respiratory Responses to Vasodilator Drugs Urecholine (Carbaminoyl Beta-Methylcholine) and Nitroglycerine
Authors: Schopp Robert T. , Gilfoil Thomas M. , Youmans William B.
Published: December 2017

The effects on respiratory rate and amplitude following intravenous injection of the vasodilator drugs, Urecholine (carbaminoyl-beta-methylcholine) and nitroglycerine were determined in dogs before and after bilateral vagotomy and isolation of the carotid sinuses. The animals were anesthetized with sodium pentothal followed by alpha-chloralose (70 mg/kg). Following the procedures for denervation of sino-aortic pressoreceptors and carotid and aortic chemoreceptors the animals showed no respiratory response to 1–2 mg sodium cyanide. It was found that the respiratory stimulation which occurs during the fall in blood pressure induced by injection of Urecholine or nitroglycerine frequently persists after sino-aortic denervation. The respiratory stimulation in the denervated animals in response to nitroglycerine was reduced or prevented in individual experiments by counteracting the fall in arterial blood pressure by means of a pressure-regulating device. It is concluded that in the dosage used nitroglycerine, and possibly also Urecholine, exert their effects on respiration indirectly by causing alterations in blood pressure or blood flow rather than through any specific action on the respiratory center.
Role of Primary Sensory Cortex in Generalized Electrocortical Activation
Authors: Beller Aaron J. , Gestring Gidon F. , Purpura Dominick P.
Published: December 2017

Experiments were performed on intact unanesthetized-succinylcholine paralyzed cats in order to compare the effects of ablations of primary cortical regions on the ability to evoke generalized activation to specific sensory stimulation with those obtained by Bremer on encéphale isolé preparations. Bilateral destruction of the auditory or somatic sensory cortex in intact preparations does not block generalized activation to auditory or sciatic stimulation. It is concluded that in the presence of spinal afferent activity as exists in the intact preparation corticifugal influences arising in either the auditory or somatic sensory cortex are not necessary for the activation process that follows auditory or sciatic stimulation.
Localized Changes in Electrical Activity of the Hypothalamus in Estrous Cats Following Vaginal Stimulation
Authors: Porter Robert W. , Cavanaugh Edward B. , Critchlow B. Vaughn , Sawyer Charles H.
Published: December 2017

In experiments designed to record central nervous electrical activity related to neurogenic stimulation of the adenohypophysis, hypothalamic EEG records were made of the effects of vaginal stimulation in the estrous cat. Mechanical stimulation, known to be capable of activating release of pituitary ovulating hormone in the estrous animal, evoked a reproducible EEG pattern in the anterior and lateral hypothalamus, in and around the medial forebrain bundle. This alteration of the spontaneous resting EEG was characterized by bursts of increased frequency and amplitude lasting several seconds or by trains of high amplitude slow waves. These changes recurred spasmodically for 3–7 minutes and may be temporally related to the behavioral after-reaction in the unrestrained unanesthetized cat. Although present in 10 out of 13 estrous cats no such EEG changes could be recorded in any of 9 anestrous animals. The likelihood that these alterations in nervous activity represent some of the electrical concomitants of neurogenic stimulation of the release of pituitary ovulatory hormone is discussed.
Comparison of the Diuretic Effects of Nitrate Salts With Other Diuretic Agents
Authors: Hiatt Edwin P.
Published: December 2017

A comparison of the diuretic effect of single large doses of NH4NO3, KNO3, NaNO3, NaCl, Diamox and Mercuhydrin was made in three dogs. Measurement was made of urinary volume, sodium, potassium and osmolar excretion during the 24-hour period following administration of each agent. The net sodium excretion was taken to be the best diuretic index for our purposes. By this index, Mercuhydrin, Diamox, and NH4NO3 were of the same order of effectiveness ( ca. 3 mEq/ kg/24 hr.), with KNO3 next ( ca. 2 mEq/kg/24 hr.) and NaNO3 still less ( ca. 0.5 mEq/kg), while NaCl was not completely excreted in 24 hours. The effect on urine volume was in the same order but with smaller differences. Net potassium excretion was significant only with the acidifying agents Diamox and NH4NO3, which caused about 2.5 mEq/kg loss in 24 hours, and NaNO3, which caused about 0.7 mEq/kg loss. The excretion of osmotically active material as measured by freezing point depression of the urine was much less than would be predicted from the cation excretion.
Renal Hemoglobin Transport: Glomerular Permeability and Tubular Reabsorption During Infusions of L-Norepinephrine
Authors: Lathem Willoughby
Published: December 2017

Effect of pressor doses of 1-norepinephrine on the glomerular permeability to hemoglobin relative to creatinine and on the rate of tubular reabsorption of hemoglobin was examined in anesthetized dogs following the administration of 2.0 grams of dog hemoglobin solution intravenously in a single dose. The administration of this hormone resulted in an increase in the relative glomerular permeability to hemoglobin and an increase in the maximal rate of tubular reabsorption of hemoglobin in 8 of 10 animals. Since glomerular filtration rate tended to fall or remained unchanged, the amount of hemoglobin reabsorbed per unit of filtrate also increased in these 8 studies. In one animal the relative glomerular permeability to hemoglobin did not change and in one it diminished. In these 2 studies tubular reabsorption remained constant or fell. Hence an inter-relationship between permeability and reabsorption appeared to exist. The mechanism of these changes was not established.
Polarity of the ST Vector
Authors: Donoso E. , Wachtel F. , Grishman A.
Published: December 2017

A technique has been evolved which yields consistently reproducible electrocardiographic records of injury effects in the dog as a result of the application of potassium chloride to the epicardium. The electrical results were recorded both by a string galvanometer and a condenser coupled amplifier electrocardiographic apparatus. The electrocardiograms taken by the two machines were different. Injury to the anterior wall of the dog's heart results solely in a depression of the baseline, the TP and PR interval segments. The ST segment ‘take off’ remains at the isoelectric level.
Alterations in Kidney Weight Produced by Escherichia coli Endotoxin
Authors: Hinshaw L. B. , Bradley G. M.
Published: December 2017

The rapid injection of E. coli endotoxin in eviscerated anesthetized dogs resulted in a sudden fall in kidney weight beginning within 15–35 seconds after injection and reaching a minimum weight within 10–20 minutes. This decrease in weight occurred independently from blood pressure changes and represented an average loss in weight of 25%. The results suggest that E. coli endotoxin either has a direct action on the renal vasculature or that it causes the liberation of an unknown substance, or substances, elsewhere in the body which act on the kidney.
Organ Weights in Three Forms of Experimental Obesity in the Mouse
Authors: Marshall N. B. , Andrus S. B. , Mayer Jean
Published: December 2017

Obesity in mice is accompanied by changes in organ weight. Certain changes, like the enlargement of the liver, heart and kidneys appear to be nonspecific effects of prolonged hyperphagia. Such changes are seen in ‘regulatory’ as well as in ‘metabolic’ obesities. Other changes may be part of a syndrome of which obesity is also a component; for example, in the hereditary obese-hyperglycemic syndrome, a metabolic form of obesity, the pancreas and the thymus are enlarged and the size of the brain decreased. These findings emphasize the need for a wider recognition of the differences between obesities of various etiologies and pathogeneses.
Serum and Serum Fractions as Antagonists for Desoxycorticosterone Inhibition of the Chick Heart in Tissue Culture
Authors: Cornman Ivor , Gargus James L.
Published: December 2017

The stimulation and subsequent suppression of cardiac activity by desoxycorticosterone has been studied on embryonic chick heart fragments in tissue culture. Three successive doses of 10γ/ml DOC were sufficient to induce cardiac stimulation while single doses of 30–40γ induced a prompt reduction in activity. Ten per cent whole serum, protein-rich serum concentrate, and ultrafiltrate were comparable in inducing a temporary reversal of the suppression induced by DOC.
Effect of Adrenalectomy on Ethanol and Fat Metabolism in the Rat
Authors: Mallov Samuel
Published: December 2017

Fasting reduced or completely prevented the accumulation of liver lipid brought about by the administration of ethanol to intact rats; the longer the fast, the greater the degree of inhibition. This is inconsistent with the hypothesis that fatty infiltration of the liver resulting from ethanol intoxication is due to mobilization of depot fat, promoted by increased secretion of pituitary and adrenal cortical hormones. Adrenalectomized rats, pair-fed with intact controls prior to alcohol intoxication, did not show fatty infiltration of the liver after such intoxication, while the controls did. When a single dose of fat was administered to pair-fed adrenalectomized and intact rats, the former showed significantly less liver lipid accumulation and significantly greater blood ketone levels than did the latter. These results are consistent with the hypothesis that fasted or adrenalectomized rats do not show liver lipid accumulation following ethanol administration because they catabolize fat in their livers more rapidly than do fed intact rats.
In Vitro Metabolism of Fatty Acids by Adipose and Liver Tissue of the Adrenalectomized Rat
Authors: Perry W. F. , Bowen Helen F.
Published: December 2017

The utilization of acetate and octanoate by adipose tissue from rats 1 and 2 weeks postadrenalectomy has been studied. In addition, acetate incorporation into liver fatty acids and ketogenesis by liver slices from 2-week postoperative animals has been measured. Adrenalectomy resulted in a progressive loss of fat from adipose tissue. At 1-week postadrenalectomy the incorporation of acetate into fatty acids by adipose tissue did not differ from the control preparations but was much increased 2 weeks after adrenalectomy. At this time there was no increase in utilization of added octanoic acid by the adipose tissue and neither at 1 nor at 2 weeks was the production of CO2 from either acetate or octanoic significantly different from normal. Liver slices from 2-week adrenalectomized animals had a markedly defective ability to incorporate acetate into liver fatty acids similar to that previously noted in 1-week animals. However, liver slice preparation from 2-week adrenalectomized rats showed increased ketone body formation, indicating increased fatty acid utilization by the liver. It is suggested that there is a gradual mobilization of fat from the depots to the liver in the adrenalectomized rat with increased utilization of fat by the liver.
Analysis of Forced Circling Induced by DFP and Ablation of Cerebral Structures
Authors: White Richard P. , Himwich Harold E.
Published: December 2017

The effects of unilateral ablation of specific prosencephalic structures in rabbits induced to circle by the administration of DFP into the right common carotid artery were studied. In most cases, ablation of the cortex did not stop the circus movements, whereas excision of the right caudate nucleus in animals circling contralaterally usually stopped this behavior. Ipsiversive turning, however, was not usually affected even with bilateral removal of the telencephalon, a finding which indicates that mesodiencephalic structures may be involved in ipsiversive responses produced by intracarotid injections of DFP. This result, together with cholinesterase activity measurements, support the conclusion that in the rodent the nucleus caudatus is principally involved in contraversive responses and mesodiencephalic structures may be important to ipsiversive turning following an injection of DFP into the right carotid artery.
Generation of Prothrombin Activity With Mitochondria or With Cathepsin
Authors: Barnhart Marion I.
Published: December 2017

Prothrombin activity can be regenerated from ‘inactive’ prothrombin in the presence of either liver mitochondria or cathepsin concentrates obtained from spleen or liver. This regeneration of prothrombin occurs more rapidly near ph 7.9. Mitochondria and cathepsin may also accelerate destruction of prothrombin activity. This occurs in acid solutions, and at ph 5 such destruction is very pronounced. Either mitochondria or cathepsin can be used under similar conditions for producing apparently identical changes in prothrombin. Most likely the agent in mitochondria which participates in the generation of prothrombin activity from a precursor is cathepsin.
Absorption of Monoglycerides
Authors: Tidwell Herbert C.
Published: December 2017

The rate of absorption of glyceryl monooleate, when fed alone, appeared to be much slower than that of other glycerides. However, the monooleate was found to be relatively unavailable for absorption because a large part of it was retained for a time in the stomach as a thick gel. In contrast, the chylomicronemia was markedly greater after feeding olive oil, Tween 80, or 1:1 mixtures of the glyceryl monooleate and olive oil or the fatty acids prepared from it. The slower absorption of the monoglyceride was not associated with a decreased lipid retention over a longer period, because eventually all of the lipid became available for absorption. In an unsuccessful attempt to prevent excessive gastric retention of this lipid, several 10% emulsions of the monooleate were employed. Observation showed that the retention in these attempts could not be attributed solely to gel formation, but more likely to a decreased gastric motility. Nevertheless, a similar rate of absorption of the monooleate and olive oil was obtained if only that part of the lipid were considered which had passed from the stomach and was therefore readily available for absorption. Insufficient evidence is at hand to determine whether the major hydrolysis of the monoglycerides, which is necessary for formation of the triglycerides of the chyle, occurs in the lumen or the mucosal cell.
Renal Metabolism of 5-Hydroxyindolacetic Acid
Authors: Despopoulos Agamemnon , Weissbach Herbert
Published: December 2017

Slices of rabbit kidney cortex concentrate 5-hydroxyindolacetic acid by an active aerobic process. The accumulation of 5-hydroxyindolacetic acid can be increased by acetate ion and decreased by dinitrophenol. In patients with malignant carcinoid, the excretion of the indole can be decreased by the intravenous administration of probenecid. These data suggest that the renal elimination of 5-hydroxyindolacetic acid, like that of p-aminohippuric acid, is achieved by glomerular filtration and active tubular excretion.
Effects of Prolonged Administration of Diamox on Excretion of Acid and Carbonic Anhydrase and Glutaminase Activities in the Kidney
Authors: Seldin Donald W. , Rector Floyd C. , Teng H. C.
Published: December 2017

Diamox inhibits renal carbonic anhydrase activity as effectively when given chronically as when given acutely. The persistently high urine ph, low titratable acid and high bicarbonate excretion in the urine of rats receiving Diamox chronically were the result of the alkaline load effects of sodium Diamox, rather than effects from the inhibition of carbonic anhydrase. The chronic administration of Diamox activated the renal glutaminase enzyme system, resulting in the excretion of normal or increased amounts of ammonia into an alkaline urine. The activation of glutaminase was potentiated by the restriction of dietary NaCl. An unexplained hypernatremia developed during the course of prolonged administration of Diamox.
Electric Potentials Across the Aorta of Dogs
Authors: Eisner Gilbert M. , Berrian James H. , Carter Edwin L. , Huggins Charles E. , Sewell William H.
Published: December 2017

Using a high impedance voltmeter in series with a pair of measuring electrodes, attempts were made to measure potential differences along and across the wall of the abdominal aorta of 28 dogs. Aortic grafts in the nature of either plastic or freeze-dried homografts had been inserted in some of these animals from 3 days to 6 months previously. In two animals with homografts a small potential gradient was demonstrable along the adventitial surface of the vessel, but in none of the animals was a potential difference detectable across the vessel when the electrodes were directly opposed. Crushing injuries to host aorta and grafts failed to produce a measurable potential difference. If potentials across blood vessel walls normally exist, these are less than 1 mv, the limit of sensitivity in the techniques and apparatus employed.
Effects of Adrenergic and Cholinergic Drugs on Splenic Inflow and Outflow Before and During Adrenergic Blockade
Authors: Ottis Kenneth , Davis J. E. , Green Harold D.
Published: December 2017

Blood flows (electromagnetic flowmeters) and lateral pressures were recorded simultaneously from the splenic artery and vein during intra-arterial injections of adrenergic substances and methacholine. These injections were repeated after progressively increasing doses of the adrenergic blocking agent phenoxybenzamine. Epinephrine and arterenol simultaneously reduced arterial inflow and increased venous outflow and splenic vein pressure, and reduced splenic volume. Isoproterenol and methacholine, and epinephrine and arterenol during partial adrenergic blockade, increased arterial inflow and venous outflow and pressure, and increased splenic volume. This is the only vascular bed so far studied in which any significant degree of reversal of arterenol arteriolar constriction has been noted.
Effect of Hypophysectomy and Subsequent Administration of Growth Hormone and ACTH on Serum Proteins of Dogs
Authors: Warner R. C. , Weber I. , de Bodo R. C. , Kurtz M.
Published: December 2017

Changes in the serum proteins of dogs following hypophysectomy and administration of growth hormone or ACTH were studied by electrophoretic analysis. In the hypophysectomized dog a drop in the albumin concentration and a rise in the globulin concentration contributed to an average decrease of 38% in the A/G ratio. The continued administration of growth hormone to hypophysectomized dogs, in dosages sufficient to abolish their insulin hypersensitivity and to increase their renal functions, caused a further reduction in the concentration of the albumin and an increase in the concentration of the total globulin, thereby further decreasing the A/G ratio. ACTH therapy restored the serum proteins to the normal range in animals in which the hormone treatment resulted in adrenal hyperplasia and a restoration to normal of the adrenal gland weight, carbohydrate metabolism and renal function
Effect of Age on Radiosodium Exchange in Bone (Rat)
Authors: Forbes Gilbert B. , Mizner George L. , Lewis Anne
Published: December 2017

On a wet weight basis, bone from young animals contains more water and chloride, and less sodium and calcium than that of the adult. In the young animal, a much larger fraction of the skeletal sodium exchanges readily with radiosodium. However, since the skeleton of the older animal has a much higher sodium concentration, the total amount of sodium per unit skeletal weight which is available for exchange does not vary appreciably with age. Sodium in bone is considered metabolically to consist of three phases: 1) ‘fluid’ phase sodium, represented by that contained in the chloride space; 2) the exchangeable portion of the ‘crystal’ phase Na; and 3) the nonexchangeable Na of the ‘crystal’ phase. Changes in the magnitude of each of these phases occurs during growth in the rat.
Effects of Oxygen at High Pressure on the Transport of Potassium, Sodium and Alpha-Ketoglutarate in Guinea Pig Kidney Cortex
Authors: Kaplan S. A. , Stein S. N.
Published: December 2017

Slices of guinea pig kidney cortex were incubated in a medium containing alpha-ketoglutarate, potassium, sodium, chloride, calcium and phosphate. After 90 minutes incubation at 37°C the potassium content of the slices diminished slightly when exposed to oxygen at a partial pressure of 1 atm. absolute. As the pressure of oxygen was raised above 2 atm. absolute, the potassium content of the slices increased over the control values by about 20% while the sodium content was decreased by a similar amount. At pressures exceeding 9 atm. absolute, the potassium content was reduced and concomitantly the sodium content was increased. Exposure of kidney slices to nitrogen at high pressure (5 atm. N2 plus 1 atm. O2) does not produce any changes in electrolyte content of the slices as compared with that of the slices exposed to 1 atm. of oxygen alone. Oxygen at high pressure does not appear to have any effect on the uptake of alpha-ketoglutarate from the medium by the slices.
Pulmonary Blood Volume of the Dog and Its Changes in Acute Heart Failure
Authors: Lindsey Arthur W. , Banahan Benjamin F. , Cannon Russell H. , Guyton Arthur C.
Published: December 2017

The volume of blood in the lungs and left heart and the amount of blood that can shift between the pulmonary circulation and the systemic circulation has been measured in intact dogs by a direct method. The systemic blood was separated from the pulmonary blood by instantaneously constricting the pulmonary artery and ascending aorta with plastic loops placed around these vessles at a previous operation. The volume of the two systems was then determined by a washout technique. In 13 control dogs the average pulmonary and left heart blood volume was 10.3 ml/kg ± 1.9 S.D. or 13% of the total blood volume. When acute right heart failure was produced by gradually constricting the pulmonary artery, the pulmonary and left heart blood volume in 12 dogs was reduced to an average of 5.3 ml/kg ± 1.0 S.D., which represents a 48% decrease below the control value. Acute left heart failure was produced by gradual constriction of the ascending aorta in 13 dogs, and the pulmonary and left heart blood volume increased to 17.5 ml/kg ± 2.8 S.D., representing a 70% increase above the control value.
Role of the Gonads in Control of Blood Pressure in Chickens
Authors: Ringer Robert K. , Sturkie P. D. , Weiss H. S.
Published: December 2017

Blood pressure changes in gonadectomized and gonadotrophin-treated chicks were utilized to determine the role of the gonads in establishing and maintaining the sex difference in pressure of the adult chicken. By the 23rd week, 4–5 weeks after the normal rise in male pressure, both capon and poulard pressures had climbed to near the male level and significantly above the female. This confirms that androgen is not essential to the rise in pressure, and indicates that other than ovarian activity, nothing inherent in the female prevents the rise. Furthermore, elevated poulard pressures could be depressed to near female levels with estrogen or 2-amino,5-nitrothiazole, presumably through suppression of pituitary gonadotrophin secretion. Exogenous gonadotrophin failed to change the pressure of the chick prematurely, despite marked sexual stimulation, suggesting that chronological maturation, possibly independent of the pituitary-gonad interrelationship, is a prerequisite.
Effect of Pitressin on the Isolated Perfused Rabbit Heart
Authors: Hanson Kenneth M. , Johnson John A.
Published: December 2017

The effect of Pitressin on the cellular content of sodium and potassium, the resistance to perfusate flow and heart rate were studied in the isolated perfused rabbit heart. The resistance to flow was markedly increased in the Pitressin-treated hearts while no significant change occurred in any of the other measured variables.
Alterations in Enzymes and Metabolites Resulting From Adaptation to Low Oxygen Tensions
Authors: Tappan Donald V. , D. Baltazar Reynafarje , Potter Van R. , Hurtado Alberto
Published: December 2017

Succinoxidase activity has been demonstrated to be significantly higher in the tissues of guinea pigs native to altitudes of 14,000–14,900 feet than in sea level guinea pigs. Desoxyribonucleic acid content is higher in the tissues of the altitude animals, indicating a larger number of cells per gram of tissue with a constant amount of succinoxidase activity per cell. ‘Antimycin A titer,’ which varies little with altitude, and cytochrome c oxidase, which is increased in some tissues of altitude guinea pigs, indicate that altitude acclimatization may be aided by increases in key reactions of enzyme series, avoiding the necessity for changes at all of the steps of the series. Altitude animals have increased glycolysis and adenosinetriphosphatase capacities and accumulate higher levels of high energy phosphate. Animals moved from one altitude to the other show changes in enzyme concentrations indicative of acclimatization.
Tissue Pigment Manifestations of Adaptation to High Altitudes
Authors: Tappan Donald V. , D. Baltazar Reynafarje
Published: December 2017

Studies on the pigment content of muscle and organ tissues of sea level and altitude (14,900 ft.) guinea pigs have demonstrated a significant increase in myoglobin in several skeletal muscles, heart and liver in sea level animals kept in the altitude for an average of 75 days. Smaller increments were indicated for the myoglobin and cytochrome c levels for the altitude compared to the sea level groups. Higher blood hemoglobin values and higher ratios of heart weight to body weight and red to white tissue in several muscles were observed for the altitude guinea pigs and add to the total body content of respiratory pigments. The relationship of pigment levels to enzyme activities and the utility of various methods for measuring tissue pigments are discussed.
Membrane Potentials in Normal, Isolated, Perfused Frog Hearts
Authors: Ware Frederick , Bennett A. L. , McIntyre A. R.
Published: December 2017

Intracellular potentials from isolated normal frog hearts were measured in a series of 29 experiments, using microelectrodes of less than 1 micron tip diameter, a cathode follower input, direct coupled amplifier, and photographic registration of an oscilloscope trace. The perfusion fluid was Clark's solution, containing 1.08 mm calcium and 1.88 mm potassium. The average of 485 measurements of the normal resting potential was 84.5 mv. The average of 421 measurements of overshoot was 18.9 mv; and the average of 421 measurements of action potential was 102.5 mv. In eight experiments, including 141 values, the maximum depolarization rate was determined, using a graphical method of analysis. The average maximum upstroke velocity was 33.9 v/sec. The voltage-time curve of the action potential during the repolarization sequence showed considerable variation from fiber to fiber, but in most cases some evidence of a ‘spike’ component was seen.
Aldolase Activity of the Heart and Skeletal Muscle of Exercised Rats
Authors: Hearn George R. , Wainio Walter W.
Published: December 2017

Young adult male Wistar rats with an average initial weight of 250 gm were exercised from 5 to 8 weeks on a training regimen consisting of swimming one-half hour daily. Pair-fed, nonswimming animals served as controls. The unit protein of the heart ventricles and gastrocnemii (mg protein/gm wet weight of organ) was in general greater for the exercised animals. Aldolase activities were determined in the heart ventricles and the gastrocnemii. The results were expressed in terms of unit activities, actual total activities and relative total activities. The exercise significantly altered the unit and relative total activities of both the heart ventricles and skeletal muscle ( P < 0.05 or < 0.01), except for the 8th week in heart, and the actual total activities of the heart ( P < 0.01), except for the 8th week.
Role of Adrenaline and Noradrenaline in Chemical Regulation of Heat Production
Authors: Hsieh A. C. L. , Carlson L. D.
Published: December 2017

Cold-adapted spinal rats showed a greater increase in oxygen consumption following adrenaline than did warm-adapted ones. Thyroidectomy reduced the responses of warm- and cold-adapted spinal rats to about the same levels. In curarized rats, exposure to cold resulted in a greater increase in oxygen consumption and lower blood glucose concentration than adrenaline injection did. While noradrenaline had little effect in warm-adapted rats, there was a marked calorigenic response in cold-adapted rats. The results indicate, in addition to the increased calorigenic action of adrenaline in cold-adapted rats, a greatly increased calorigenic response to noradrenaline. The possibility that noradrenaline may be the mediator in chemical regulation of heat production is discussed.
Role of the Sympathetic Nervous System in the Control of Chemical Regulation of Heat Production
Authors: Hsieh A. C. L. , Carlson L. D. , Gray G.
Published: December 2017

The ganglionic blocking agent hexamethonium chloride and the adrenolytic agent piperoxane hydrochloride prevented the increase in oxygen consumption otherwise observed in curarized, cold-adapted rats exposed to cold. Atropine sulfate had no effect. The sympathetic nervous system, including the adrenal medulla, appears to be important in the mediation of chemical regulation of heat production in these animals. L-noradrenaline was more effective than adrenaline in preventing the fall in oxygen consumption caused by hexamethonium. This finding suggests that noradrenaline may also play an important part in chemical regulation.
Alterations in Metabolism During Electrical Excitation of Frog Nerve
Authors: Samuels Arthur
Published: December 2017

Isolated frog sciatic nerves, after preliminary soaking in tracer phosphate (P32), showed an increased uptake into the labile phosphates, phospholipids (P.L.) and residual phosphates (R.P.) and a decreased uptake into the glycolytic intermediates, and nucleic acids (N.A.P.) during subsequent stimulation as compared to rest. This evidence for increased oxidative phosphorylation and decreased glycolysis during electrical excitation is supported by analytical evidence showing an increased concentration of glycolytic intermediates and lactic acid in the absence of decreased carbohydrate precursors, during electrical stimulation.
Metabolism of Octanoate by Fatty Liver Slices
Authors: Rees E. Douglas , Kline Daniel L.
Published: December 2017

Metabolism of octanoate by slices of fatty liver from choline-deficient rats was studied by manometric determinations of Qo2 and Qco2 and by direct chemical determinations of octanoate utilization. The Qo2 in the absence of added substrate was lower for fatty liver. The R.Q. of the control slices but not of the fatty liver slices decreased markedly in the presence of octanoate due to the lowering of the Qco2. This was interpreted to mean that there is an impairment in the oxidation of fatty acids by fatty liver slices, and that this impairment is predominantly in the formation of ketone bodies.
Refractoriness in Cardiac Muscle
Authors: Hoffman Brian F. , Kao C. Y. , Suckling E. E.
Published: December 2017

A preparation consisting of a papillary muscle and attached bundle of Purkinje fibers has been employed to study refractoriness of single cardiac fibers of the dog heart. Transmembrane stimulation of single fibers and records of the transmembrane potential have been used to compare the stimulating efficacy of applied current pulses and normally propagated action potentials. The absolute and effective refractory period and full recovery time of the single cardiac fiber are outlined in a similar manner by both applied cathodal stimuli and the propagated action potential. Two factors, a local response and a change in the local action potential, have been shown to contribute to the latency of response to stimuli applied during the relative refractory period. These studies have also demonstrated a considerable safety factor in propagation in cardiac muscle.