bluuebunny/crossref_metadata_2025 huggingface dataset:
Pancreatic Lipase—Determination in Canine Pancreatic Secretion and Human Blood Serum
Authors: Guth Paul H. , Komarov S. A. , Shay Harry , Style C. Zislin
Published: December 2017

A previously reported method for lipase determination was modified to increase the sensitivity so as to permit application of the method without change to both pancreatic secretion and human blood serum. The errors determined in serial dilution experiments with pancreatic secretion were found to be 9.2% for deviations from linearity, and 9.1% for duplicate error (both expressed as coefficient of variation). The method was applied to the reinvestigation of the question of the lipase/protein nitrogen relationship in canine pancreatic secretion obtained a) under as identical conditions as possible, and b) following different test meals and dietary regimens. Two statistical approaches were utilized: a) analysis of covariance, to evaluate variations in the lipase activity/protein nitrogen relationship, and b) analysis of variance, to evaluate variations in the lipase concentration/protein nitrogen relationship. Highly significant variations in both ratios from specimen to specimen were found in the vast majority of our studies. These variations did not conform to the concept of adaption of the individual enzymes to the type of food ingested. Studies with human blood serum revealed the method to be specific for pancreatic-type lipase. No lipolytic activity was detected in normal serum, while in many cases of pancreatic disease, not only was lipolytic activity detected, but the lipase concentrations observed closely followed the clinical course of the disease. The reliability, specificity and rapidity of the method make it suitable for clinical studies.
Hemodynamic Determinants of Coronary Flow: Effect of Changes in Aortic Pressure and Cardiac Output on the Relationship Between Myocardial Oxygen Consumption and Coronary Flow
Authors: Braunwald E. , Sarnoff S. J. , Case R. B. , Stainsby W. N. , Welch G. H.
Published: December 2017

Although the general dependence of coronary flow on myocardial qo2 was confirmed in an in situ heart preparation, changes in aortic pressure and cardiac output were observed to be capable of influencing this relationship. Neither myocardial qo2 nor coronary flow were found to be dependent on left ventricular filling pressure.
Effects of Carbon Dioxide on Brain Excitability and Electrolytes
Authors: Woodbury Dixon M. , Rollins Lawrence T. , Gardner Morris D. , Hirschi Wayne L. , Hogan John R. , Rallison Marvin L. , Tanner George S. , Brodie David A.
Published: December 2017

Effects of various concentrations of CO2 on brain excitability and electrolyte distribution in rats were studied, and also some properties of seizures induced by abrupt withdrawal from high concentrations of CO2. Inhalation of relatively low concentrations of CO2 (5–20%) decreases brain excitability, as measured by an increase in electroshock seizure threshold (EST). In moderately high concentrations (25–40%), CO2 increases brain excitability, as measured by a decrease in EST and the appearance of spontaneous seizures. Inhalation of high concentration of CO2 (40% or higher) markedly decreases brain excitability and causes anesthesia. Thus the effect of CO2 on brain excitability is related to the concentration inhaled. Abrupt removal of rats from high (anesthetic) concentrations of CO2 results in spontaneous clonic seizures within 30 seconds to 1 minute after withdrawal; these seizures last for 1–2 minutes. Inhalation of 50% CO2 decreases brain intracellular Na and K concentrations and produces a marked cellular acidosis. Thirty seconds after abrupt withdrawal of rats from 50% CO2, but prior to the onset of seizures, the concentration of Na in brain cells increases and the concentration of K decreases.
Acid-Base Changes in Brain and Blood of Rats Exposed to High Concentrations of Carbon Dioxide
Authors: Brodie David A. , Woodbury Dixon M.
Published: December 2017

Blood ph, total plasma CO2 and total brain CO2 were determined in the following groups of rats: untreated controls, exposure to 30% CO2, exposure to 50% CO2 and 30 seconds after abrupt withdrawal from 50% CO2. Values were calculated for plasma concentrations of bicarbonate ion and carbonic acid, and for intracellular brain CO2, carbonic acid, bicarbonate and ph. Inhalation of 30% CO2 increased carbonic acid and bicarbonate concentration in plasma and brain cells, and decreased intracellular ph moderately. When the concentration of inhaled CO2 was increased from 30 to 50%, there was a further marked fall in the ph of blood and brain cells, a significant further increase in the amount of carbonic acid in plasma and brain, but no significant further increase in the bicarbonate ion concentration in plasma or brain. On abrupt withdrawal of rats from 50% CO2, the ph of the blood and the brain moved into the range of the ph of the 30% CO2 rats, bicarbonate ion concentration fell below control values; brain bicarbonate ion concentration, however, remained markedly elevated.
Increased Muscle Permeability to Aldolase Produced by Insulin and by Albumin
Authors: Zierler Kenneth L.
Published: December 2017

Insulin and fraction V of serum proteins increased aldolase efflux from isolated rat peroneus longus, a muscle in which fibers are not cut. The effect upon aldolase efflux in this preparation was about as marked as the effect of insulin upon glucose uptake. Since increased aldolase efflux is assumed to result only from increased membrane permeability the data are interpreted to demonstrate that insulin alters muscle membrane, reducing its ability to serve as a barrier to diffusion.
Effect of Denervation on Experimentally Induced Changes in the Growth of Bone and Muscle
Authors: Selye Hans , Bajusz Eörs
Published: December 2017

Experiments on albino rats indicate that, following complete intrapelvic severance of the femoral, obturator and sciatic nerves, the growth in length of the inactivated tibia continues at a normal rate. The denervated bone also retains its sensitivity to the growth-promoting effect of somatotrophic hormone (STH) and to the growth-inhibitory effect of a variety of agents, such as dihydrotachysterol, cortisol and estradiol. The characteristic pathologic changes normally produced in bones by an excess of dihydrotachysterol or vitamin A are likewise not prevented by central denervation. On the other hand, the morbid lesions characteristic of bone lathyrism are greatly diminished following central denervation; presumably, these changes depend upon the functional activity of the legs. The experiments also indicate that the atrophy of a muscle (triceps surae), that follows severance of its motor nerves, can be further enhanced by certain compounds which produce intense catabolism (e.g., dihydrotachysterol, cortisol, estradiol, thyroxin), and delayed by an anabolic hormone such as STH.
Ionic Composition of the Aorta in Renal and Adrenal Hypertension
Authors: Tobian Louis , Redleaf Paul D.
Published: December 2017

The ionic composition of the aorta of the rat was studied in ‘postdesoxycorticosterone’ hypertension, ‘adrenal regeneration’ hypertension, and the hypertension which persists after excision of an ischemic kidney. The development of hypertension as a result of each of these procedures was associated with an increase in intracellular sodium and potassium content of the aorta. These findings are similar to those obtained in other forms of experimental hypertension. If similar compositional changes occur in arterioles, they may be important in the altered peripheral vascular resistance which characterizes hypertension.
Extrarenal Factors in Diabetes Insipidus in the Rat
Authors: Friedman Sydney M. , Scherrer Harald F , Nakashima Miyoshi , Friedman Constance L.
Published: December 2017

Using inulin as indicator of the extracellular volume, the distribution of sodium, potassium and water was studied in rats with diabetes insipidus produced by interrruption of the supraoptico-hypophyseal tract. A well defined increase in the extracellular fluid volume associated with normal plasma sodium and reduced plasma potassium concentration was uniformly present in the rats with diabetes insipidus. These changes occurred in nephrectomized animals and were thus independent of renal function, but were in some degree referable to an increase in adrenal function since they could be partially reversed by adrenal ablation.
Model of Storage Space in the MES Auditory Cortex
Authors: Tunturi Archie R. , Dudman John A.
Published: December 2017

A model of the MES auditory area was formulated in order to count the number of different response patterns resulting from signals in the left and right ears under various conditions. The elementary sound signals for the model were similar to the short duration, narrow band pulses, which had been used experimentally. The elementary responses for the model were simplified from data obtained from experiments in which strychnine had been used locally. Combinatorial analysis and the methods of Shannon were used in counting the patterns of the model. With all signals considered for one ear, the number of patterns was greatest on the ipsilateral side. With all signals considered independently for both ears, the total number of patterns was equal on both sides and was the greatest count observed. Reducing the intensity of the components in one ear but keeping the spectrum of the signals the same for both ears, caused an increase in number of patterns on the side having the highest intensity of its components. The estimate of the total number of patterns suggests a lower limit for the storage capacity in the MES auditory area. The storage capacity is given by the logarithm to the base 2 of the number of patterns.
Effect of Cooling on Neuromuscular Transmission in the Frog
Authors: Li Choh-Luh , Gouras Peter
Published: December 2017

Recording with intracellular electrodes from endplate regions of frogs sartorius muscle showed that at –1°C miniature endplate potentials still occurred and that the resting membrane potentials differed very little from those recorded at room temperatures. The miniature potentials, however, were decreased in frequency and increased in amplitude by cooling; and at about 5°C, the amplitude began to fall while the frequency continued to be low. It was also at about 5°C that the muscle responses to nerve stimulation frequently consisted of endplate potentials only. Upon rewarming spike potentials again appeared. These observations suggest that there is a critical temperature for neuromuscular transmission, below which impediment of impulse transmission began; and in the frog it is 5°C. The experiments also demonstrated that during the process of cooling a blockage of impulses at one neuromuscular junction and transmission across the other in a single muscle fiber could occur.
Renal Response to Carbonic Anhydrase Inhibitor in Water-Loaded Intact and Adrenalectomized Rats
Authors: Olewine Donald A. , Perlmutt Joseph H.
Published: December 2017

Renal excretions of water, Na+ and K+ were determined over a 5-hour period in sham-operated and adrenalectomized male rats injected intraperitoneally with water (5% body wt.) at postoperative intervals of 3, 14, 21 and 28 days. Intact animals maintained fairly constant outputs. In the adrenalectomized group: decreased excretion of water was apparent by 3 days, but was not maximal until after this interval; Na+ excretion increased after 14 days and rose progressively; and K+ excretion was maximally depressed by 3 days. Diamox (25 mg/100 gm body wt.) increased these values in both groups. The absolute increases in water and K+ excretion for the adrenalectomized animals were less than those for the intact animals, while Na+ excretion exceeded that of the intact group at the 14-day and subsequent intervals. These data indicate that the diuretic does not completely overcome the increased water reabsorption occurring after adrenalectomy and that the Na+—K+ exchange mechanism operates at a reduced capacity. Diamox was ineffective in protecting adrenalectomized rats against water intoxication.
Evidence of Circulatory Failure in the Early Radiation Response of the Chicken
Authors: Stearner S. P. , Sanderson M. H. , Christian E. J. , Brues A. M.
Published: December 2017

The early radiation syndrome in the chicken is distinct from that associated with death several days after exposure. In both young chicks and adult roosters, the mode of early death is characterized by a progressive circulatory collapse. To obtain more precise estimates of the circulatory changes in the initial postirradiation period, we have measured total peripheral blood volume and the blood volume of several visceral organs and of skeletal muscle. Determinations were made on control and x-irradiated chicks and adult roosters. In chicks the postirradiation decrease in actively circulating blood volume ranged from 30 to 60%. Previous studies of hemorrhagic hypotension in chicks have shown that loss of one-third of the circulating blood volume was sufficient to produce irreversible shock and renal failure. Roosters, however, can compensate for much greater loss in blood volume. Loss by hemorrhage of more than 60–70% of the normal circulating volume is frequently required to produce irreversible shock. In x-irradiated roosters, values obtained from the peripheral blood indicated no decrease in volume of circulating red cells and a 30% decrease in plasma volume. The distribution of erythrocytes and plasma, however, was significantly altered. The decrease in circulating blood volume was most marked in liver, spleen and kidneys and was probably sufficient to cause a significant decrease in function.
Evidence of Central Nervous System Influence Upon Cold-Induced Acceleration of Thyroidal I131 Release
Authors: Knigge Karl M. , Bierman Stanley M.
Published: December 2017

During the initial 12 hours of cold-exposure (5°C) of the hamster, thyroidal I131 release is accelerated markedly. Bilateral nephrectomy, adrenal demedullectomy or adrenalectomy do not influence this response. Treatment of animals with reserpine, placement of appropriate median eminence lesions 24 hours before exposure, or chronic lesions (3–6 weeks) do not interfere with subsequent normal hormone delivery but do block the accelerated release attendant upon cold exposure. Using hypophysectomized hamsters, I131 uptake is restored to normal by treatment with TSH. After this uptake is achieved and exogenous TSH discontinued, release from the thyroid is slow and cannot be accelerated by cold. Transplantation of fragments of 1/2–2 pituitary glands into the cheek pouch of hypophysectomized hamsters temporarily restores both uptake and release. Cold-exposure, however, does not accelerate thyroidal release in such graft-bearing animals. These experiments indicate that upon cold-exposure a central nervous system stimulus is responsible for triggering the pituitary-thyroid system and that the accelerated thyroidal I131 delivery, depending upon increased secretion of TSH, requires adenohypophyseal tissue with its normal anatomical connections to the hypothalamus.
Effects of Anisotonicity in the Cisterna Magna and Fourth Ventricle of Cats
Authors: Andrew John , Taylor Julien
Published: December 2017

Following the observation that distilled water, when introduced into the cisterna magna of a cat, produced marked disturbances of autonomic function, a series of experiments was carried out to determine the effect of altering the tonicity of the cerebral spinal fluid. Observations were made on 20 cats under general anesthesia. Precautions were taken to eliminate undesirable effects from raised intracranial pressure. An increase in osmotic tension was found consistently to stimulate respiration and cause marked changes in the electrocardiogram. Reduction of the osmotic tension depressed respiratory function and could cause death. Evidence obtained from a) recording electrical activity in different parts of the brain, b) applying distilled water and hypertonic sodium chloride directly to various parts of the central nervous system, and c) interruption of neural pathways, suggests that an area of special sensitivity to alterations of tonicity in the cerebral spinal fluid exists, and that it is located in the floor of the fourth ventricle.
Gastric Contractions in the Rat
Authors: Morrison Seoras D. , Lin Hsiang Ju , Eckel Helen E. , Van Itallie Theodore B. , Mayer Jean
Published: December 2017

A method is described for continuous recording of gastric concentrations in the normal rat. Fasting concentrations normally show a cyclical behavior with a period of 15–20 minutes. These concentrations are inhibited by instillation of many substances into the stomach via a permanent gastric fistula, the duration of the inhibition varying with volume and concentration. Neither glucose nor insulin given i.v. affects the fasting contractions; however, 0.1 mg of intravenous glucagon invariably produces complete inhibition of contractions for 4–7 minutes.
Quantitative Effects of Bile Salt and Fatty Acid on Cholesterol Absorption in the Rat
Authors: Vahouny George V. , Woo C. H. , Treadwell C. R.
Published: December 2017

The influence of various molar proportions of oleic acid and sodium taurocholate on the absorption of cholesterol and upon the lipid partition of thoracic duct lymph has been studied. In bile fistula rats a marked reduction of all lipid fractions of lymph was evident. The administration of oleic acid, taurocholate and cholesterol, singly or in various combinations to these animal preparations failed to elevate the lipid levels to those found in the fasting control animals having a normal bile circulation. The inclusion of up to 430 mg of taurocholate in an intragastric emulsion containing 50 mg of cholesterol and an excess of fatty acid failed to produce significant absorption of cholesterol, emphasizing the importance of the continuous circulation of the bile constituents for the absorption of cholesterol. In lymph fistula animals a molar relationship of oleic acid, taurocholate and cholesterol of 8:4:1 was found to be most effective for lipid and cholesterol absorption from the intestine and phospholipid production by the intestinal mucosa. Several levels of cholesterol greater than 50 mg were administered in emulsions in which the contents of fatty acid and bile salt were optimum for cholesterol absorption at the 50-mg level. No increase in absorption occurred either in absolute amounts or in percentage of the administered sterol. The results of these studies indicate the necessity of fatty acid, bile salt and cholesterol, present at the same time and in the proper molar amounts, for optimal transfer of fatty acid and cholesterol in the rat.
Effect of Glucagon on Peripheral Utilization of Glucose
Authors: Tomizawa Henry H. , Hyde Paul M.
Published: December 2017

Crystalline glucagon or glucose was administered to anesthetized normal and depancreatized dogs. Arteriovenous differences in blood sugar levels during the course of hyperglycemia produced by these substances were compared. Since the data obtained were quite similar, there was no evidence to indicate that glucagon has a direct enhancing effect on the peripheral utilization of glucose.
Influence of Testosterone Propionate on the Succinic Dehydrogenase Activity of Male Rat Liver
Authors: Rindani T. H.
Published: December 2017

Castration of male rats was shown previously to cause an increase of the succinic dehydrogenase activity in male rat liver homogenate. The present study was undertaken to examine if this increase was influenced by testosterone administration to the castrated animals over different periods of duration. It was observed that testosterone treatment counteracted the increase in the enzyme activity caused by castration and that this effect was more marked with longer duration of the hormone administration. Further the succinic dehydrogenase activity was not related directly to the wet weight of the liver.
Cerebral Blood Flow in the Rat
Authors: Sapirstein Leo A. , Hanusek Gordon E.
Published: December 2017

The cerebral uptake of iodoantipyrine (I131) was measured in anesthetized rats as a function of time after a single intravenous injection. The cerebral content stabilized in 7–9 seconds and remained constant for 64 seconds indicating that the brain and body had the same extraction ratio for the label. The cerebral blood flow fraction therefore corresponded to the fractional uptake of iodoantipyrine by the brain. The cerebral blood flow was calculated as the product of the cardiac output and the cerebral flow fraction. The perfusion rate of the brain was found to be 0.51 ml/gm/min. in female rats.
Relation of Hypoxemia and/or Hypocapnia to Lactic Acid Content of Brain and Cardiovascular Response
Authors: Biddulph Clyde , Van Fossan Donald D. , Criscuolo Dominic , Clark Robert T.
Published: December 2017

The lactic acid concentration of brain was measured 3 hours after death in dogs which had been subject to hypocapnia, hypoxemia with hypocapnia, and hypoxemia without hypocapnia for 15 minutes. There was no elevation of brain lactic acid above the control level in those dogs subjected to hypocapnia or hypoxemia alone, however, when hypocapnia and hypoxemia were combined there was a significant increase. Cardiovascular and blood chemical analyses support the conclusion that variations in cerebral blood flow, availability of oxygen at the tissue level and interference with oxidative metabolism are important determining factors in brain lactic acid build-up. The results agree with those obtained in altitude-exposed animals, for they likewise show an elevation of brain lactic acid.
Effect of Estrone on Some Criteria of Thyroid Function
Authors: Florsheim Warner H.
Published: December 2017

The effects of estrogen upon thyroidal I131 uptake, hormone discharge, total iodine content and distribution of radioiodine among the iodinated amino acids of the thyroid gland have been investigated in orchiectomized rats. Acute administration of estrone increased significantly the 24-hour I131 uptake and augmented thyroidal weight at the higher of the two levels employed. It had no effect upon the serum PBI, the I127 content of the thyroid or the iodinated amino acid pattern. I131 discharge from the thyroid was slowed significantly by estrone, both on a stock diet and when propylthiouracil was used to block I131 reaccumulation.
Hypertrophy and Changes in Cholinesterase Activities of the Intestine, Erythrocytes and Plasma After ‘Partial’ Resection of the Small Intestine of the Rat
Authors: Loran M. R. , Althausen T. L.
Published: December 2017

‘Partial’ resection of the small intestine in rats resulted in a disproportionately great impairment of absorption of vitamin A and several lasting anatomical and enzymatic changes. Anatomical changes consisted of a true hypertrophy of the remaining intestine, indicated by an increase in its wet and dry weight. Simple transection produced some increase in the weight of the intestine, and sham operation resulted in loss of intestinal tissue. Our interpretation of these data is that the stress of the abdominal operation results in loss of intestinal tissue, whereas actual removal of a section of the intestine releases a mechanism for restoration of lost tissue. Enzymatic changes after resection consisted of an increase in cholinesterase activity of the intestine and erythrocytes, which was not observed after simple transection or sham operation. All three groups of rats showed an increase in cholinesterase activity of the plasma. Our tentative conclusions from these data are: a) Regenerated intestinal tissue is capable of synthesizing cholinesterase. b) Disproportionately greater impairment of intestinal absorption of vitamin A after resection may be caused in part by a disequilibrium in the acetylcholine-cholinesterase system in favor of cholinesterase. c) Increase in the specific cholinesterase activity of the erythrocytes may be related to the mechanism responsible for the intestinal hypertrophy. d) Increase in the cholinesterase activity of the plasma is caused by the abdominal operation per se.
Concentrations of K and Na in Skeletal Muscle of Mice With a Hereditary Myopathy (Dystrophia Muscularis)
Authors: Baker Nome , Blahd William H. , Hart P.
Published: December 2017

Exchangeable body potassium (Ke), muscle potassium and muscle sodium concentrations have been measured in hereditarily dystrophic mice and in their normal littermates. Both Ke and K39/gm muscle were depressed in the dystrophics approximately 20% below the mean normal value; however, the concentration of Na23/gm muscle was higher by 50%, on the average, in the dystrophic tissue. The data suggest a partial replacement of intracellular by extracellular space in the dystrophic mice. Thus, this form of hereditary muscular dystrophy is qualitatively similar, with regard to K and Na concentrations, to human muscular dystrophy, vitamin E deficiency in rabbits, nutritional dystrophy in calves, and denervation in puppies.
Effect of Serotonin on Renal Hemodynamics and Sodium Excretion in the Dog
Authors: Blackmore William P.
Published: December 2017

The effects of constant intravenous infusion of serotonin with doses of 5 and 10 µg/kg/min. on glomerular filtration rate, effective renal plasma flow, urine flow and sodium excretion were studied in trained, unanesthetized female dogs. A small but significant decrease in glomerular filtration rate associated with increased renal plasma flow occurred at the 5 µg/kg/min. dose indicating a specific effect of serotonin on the kidney. Similar changes were noted with the 10 µg/kg/min. dose plus a marked antidiuretic effect that occurred in the absence of any significant change in mean arterial blood pressure and an intact neurohypophysis indicating a direct action on water reabsorption in the kidney. Urinary sodium excretion decreased with both doses as a result of a decline in glomerular filtration rate associated with increased tubular reabsorption. These results indicate that serotonin has a specific effect on the kidney and suggest that this substance may alter the caliber of the glomerular vessels to decrease renal vascular resistance.
Changes in Renal Blood Flow in Dogs During the Inhalation of 30% Carbon Dioxide
Authors: Stone Joseph E. , Wells J. , Draper W. B. , Whitehead Richard W.
Published: December 2017

Mongrel dogs lightly anesthetized with thiopental sodium were used as experimental animals. After suitable controls were taken the changes in renal blood flow, urine volume, venous blood pH, blood pressure and heart rate, respiratory rate and volume and relative blood cell volume were measured at intervals during inhalation of 30% carbon dioxide in oxygen for 30 minutes. No anesthetic was administered during the period when CO2 was inhaled. No constant change in pH, hematocrit or heart rate was observed to result from the CO2 inhalation. Respiratory rate increased throughout the experiments. The inhalation of 30% carbon dioxide in oxygen produced a marked reduction in renal blood flow, concomitant with a marked oliguria. The renal ischemia under these conditions was prevented by pharmacological block of the left renal nerves (by injection of 5 ml of .5% tetracaine into the peripelvic area of the kidney). The pharmacologically denervated kidney continued to secrete urine in somewhat diminished quantities while the undenervated kidney developed severe oliguria or anuria. It is postulated that the renal ischemia observed in these experiments is a component of a generalized centrally induced vasoconstrictor response to the inhalation of a high concentration of carbon dioxide.
Lymphatic Permeability to Albumin
Authors: Patterson Rodney M. , Ballard Charles L. , Wasserman Karlman , Mayerson H. S.
Published: December 2017

Radioactive albumin was infused proximally into a leg lymphatic of dogs at a constant rate, thoracic duct lymph and blood were sampled for 150 minutes and the radioactive albumin in these fluids determined. The infused albumin returns to the circulation primarily by the thoracic duct. Less than 3% of the infused albumin reaches the circulation by routes other than the thoracic duct except in unusual cases of right and left thoracic duct anastomoses. Lymph nodes do not phagocytize the serum albumin passing through them and exchange of albumin between lymph and blood in lymph nodes is quantitatively insignificant.
Production of Experimental Hypertension and Cardiovascular-Renal Lesions With Licorice and Ammoniated Glycyrrhizin
Authors: Girerd R. J. , Rassaert C. L. , Di Pasquale G. , Kroc R. L.
Published: December 2017

The intragastric administration of either licorice or ammoniated glycyrrhizin for 50 days to male rats, unilaterally nephrectomized and given 0.87% sodium chloride solution to drink, caused a blood pressure elevation consistently higher than that induced by DCA under similar conditions. Renal and cardiovascular lesions, consisting essentially of arteriolar necrosis and hyalinization, were very severe in the DCA- and licorice-treated groups, while they were milder in the glycyrrhizin group. Licorice or DCA treatment caused a significant polydipsia and growth impairment, whereas the curves of fluid intake and body growth of the glycyrrhizin treated group remained approximately like those of the controls. These results support some previous reports on the steroid-like activity of licorice. It seems that the hypertensive properties of licorice could be attributed to its glycyrrhizin content, while polydipsia and some other effects may be due to other constituents.
Interaction of Stretch and Ryanodine on Oxygen Uptake in the Rat Diaphragm
Authors: Whalen William J. , Dernberg Ernest , Jenden Donald J.
Published: December 2017

The relation between oxygen consumption, length and tension of isolated strips of rat diaphragm was examined as a function of the concentration of ryanodine. The influence of mechanical stretching on oxygen consumption of resting rat diaphragm was found to be very small compared with that reported in Rana temporaria There is evidence that the stretch response is related to an increase in length rather than to rise in tension; the latter per se may have a negative influence on Qo2. Ryanodine causes a small but definite rise in Qo2; in contrast to frog muscle, no significant difference was observed between muscles maintained isometrically and those which were allowed to shorten. The limited observations which have been made on different species are consistent with the possibility that the Qo2 responses to stretch and to ryanodine may involve a common mechanism.
Bilateral Asymmetry of Rat Brain Calcium
Authors: Streicher Eugene
Published: December 2017

Values ranging between 2.2 and 9.0 mEq/kg were found for the calcium content of rat brain. In half the tissues examined, the figures for the two halves of the same brain differed from each other by more than 100%. Evidence is presented which indicates that values in excess of approximately 2–3 mEq/kg probably represent calcium deposition in nonparenchymal structures of the brain.
Determination of Blood Flow to the Rat Pituitary Gland
Authors: Goldman Harold , Sapirstein Leo A.
Published: December 2017

A radioactive tracer method, employing Rb86, is described for measurement of hypophyseal blood flow in the pentobarbitalized rat. The results indicate that the perfusion rate of the posterior lobe is 3.6 ml/gm/min. The anterior lobe has a minimal perfusion rate of 0.59 and a maximum of 0.90 ml/gm/min. under the experimental conditions employed. The time pattern of Rb86 uptake of both lobes of the pituitary is similar to that of non-nervous tissue, indicating that the blood-brain barrier does not extend into either part of this gland.
Excretion of Sodium and Water in Rats Made Hypertensive by Subtotal Nephrectomy
Authors: Ezrow Leonard , Sapirstein Leo A.
Published: December 2017

The excretion of sodium and water by rats made hypertensive by subtotal nephrectomy in basal circumstances and after loading with various saline solutions shows these animals to have essentially normal patterns of sodium excretion. Water excretion, however, is invariably greater than that observed in normal animals. The hypertensive animal thus has a continually greater load of sodium on his body water than the normal in comparable circumstances. Some possible implications of these findings are discussed.
Investigation of Mechanism of Diuresis Produced in the Rat by an Intravenous Infusion of Isotonic Solution of Sodium Chloride
Authors: Keeler R. , Schnieden H.
Published: December 2017

Following intravenous infusions of isotonic saline a marked increase in the tubular rejection fractions for sodium and water occurred. Only a slight rise in inulin clearance was found. Since the expansion of plasma volume produced by 6% albumin in isotonic saline solution was less effective in producing a diuresis than a similar expansion of plasma volume by an infusion of isotonic saline the results suggest that plasma volume expansion alone could not account for all the effects observed in saline diuresis. Dilution of plasma proteins may have played some part but bilateral vagotomy or bilateral severance of the cervical cardiac branches of the vagus did not significantly affect the diuretic response to an intravenous infusion of 0.9% sodium chloride solution.
Dietary Cholesterol and Adrenal Regulation of Plasma Lipids
Authors: Powers B. S. , Di Luzio N. R.
Published: December 2017

Adrenalectomized dogs maintained on desoxycorticosterone acetate manifest a progressive depletion of plasma phospholipid and cholesterol. Within a 4-week period a mean decrease of 60% is observed. The daily addition of cholesterol to the Purina chow diet prevented the hypolipemic response and resulted in significant elevation in the concentration of plasma cholesterol. The feeding of an identical amount of cholesterol to dogs with intact adrenals was not associated with any alteration in plasma lipid levels. The feeding of identical amounts of highly saturated fats or soya lecithin to adrenalectomized dogs resulted in the characteristic decline of plasma phospholipid and cholesterol. A significant contribution of the adrenal gland to the regulation of plasma lipid metabolism in normal and cholesterol-fed dogs is indicated.
Antagonistic Effects of Acetylcholine and Nicotine on Isolated Frog Hearts
Authors: Pathak C. L.
Published: December 2017

A study of the relationship between the actions of acetylcholine and nicotine on frog hearts indicates that both the excitatory and inhibitory effects of acetylcholine are antagonised by nicotine. Hearts stopped by acetylcholine and also spontaneously stopped hearts were restarted by nicotine. It has been suggested that exogenously administered acetylcholine and nicotine act through same receptors in a competitive manner.
Effect of Atrial Systole on Ventricular Pressure at Variable P-Q Intervals
Authors: Siecke Helmut , Essex Hiram E.
Published: December 2017

Eight dogs with complete atrioventricular heart block showed a definitive relation between the P-Q interval and the systolic left ventricular pressure if the P-Q interval increased or decreased slowly at a regular rate. The ventricular pressure reached a ‘plateau-like’ maximum at a P-Q interval between 0.1 and 0.2 second, and decreased only slightly with somewhat longer P-Q intervals. The lack of abrupt decrease in pressure suggests that the mitral valve closes passively during early atrial diastole and that this prevents rapid regurgitation of blood into the left atrium.
Electrical Activity of the Small Intestine With Special Reference to the Origin of Rhythmicity
Authors: Holaday Duncan A. , Volk Herbert , Mandell Julian
Published: December 2017

Unipolar recordings of small intestinal potentials were obtained from chronic dog preparations with exteriorized segments of bowel, from anesthetized dogs, cats and rabbits at laparotomy and from unanesthetized human subjects. Two dominant types of electrical activity were observed and correlated with function. The first type consisted of brief, nonpropagated, spike-like negative potentials which occurred only immediately preceding and during contraction and varied in frequency of occurrence proportionate to intensity of contraction. It is concluded that they represent the action potentials of contracting muscle fibers. The second type of electrical activity consisted of a recurring complex of slow potential changes, the configuration of which varied with the region of intestine and type of preparation. The complex was most stable and most clearly defined in transplanted segments of dog jejunum. The form of the complex was not altered by anesthetics or by sympathomimetic or parasympathomimetic drugs, and was the same during inactivity as during contractions. Initiation of contractions occurred only during the relatively positive phase of the slow complex. It is concluded that the slow complex is a cyclic alteration of the resting potential of the smooth muscle cells of the intestine which originates more or less synchronously in adjacent cells and is associated with a mechanism which renders the muscle alternately relatively excitable and absolutely refractory.
Effect of Derivatives and Inhibitors of Histamine Metabolism on Gastric Secretion
Authors: Ivy A. C. , Liepins K. W.
Published: December 2017

Since the derivatives of histamine metabolism are quite well known, those which have been synthesized were tested for gastric secretory activity in Heidenhain pouch dogs. All were inactive in a single total dose of 20 mg or 1.7 mg/kg. N-acetylhistamine is 1000 times less active than histamine. 1-Methyl-4-(aminoethyl) imidazole, the first derivative produced by the methylation of histamine in the liver, was inactive. Imidazole-4-acetaldehyde, the first derivative of the oxidative deamination of histamine has not been synthesized, but the next derivative, imidazole-4-acetic acid, was inactive. Among the five histamine diamine oxidase inhibitors studied in relation to gastric secretion to date, aminoguanidine is the most ideal. It has the additional advantage of not inhibiting histidine decarboxylase.
Effects of Hypoxia on the Course of Induced Fever in Dogs and Monkeys
Authors: Kubicek W. G. , Anderson W. D. , Geber W. F.
Published: December 2017

Data were obtained in regard to rectal temperature, inspired pO2, circulation, metabolic rate and hematology. Fevers ranged from 39°C to 45°C and inspired pO2 from 25 mm Hg to 83 mm Hg during hypoxia. In control experiments on dogs with normal body temperature hypoxia resulted in a fall in body temperature, blood O2 and CO2 content, while pulse rate, blood sugar, plasma creatinine and hematocrit increased. The main effects of induced fever in these animals breathing air were an increase in pulse rate, plasma creatinine, blood pH, blood O2 content, hematocrit, O2 consumption rate and CO2 production. Blood sugar usually decreased. Blood pressure either remained essentially constant or fell during the most rigorous experiments. Total leucocyte counts indicated a trend toward an increase and differential counts indicated a rise in the proportion of segment nuclears and a fall in the relative number of lymphocytes. Hypoxia superimposed upon fever resulted in an increase in rectal temperature in 31%, a decrease in 20% and no change in 49% of the experiments, indicating that under certain conditions hypoxia can aggravate a febrile condition by further elevating body temperature. Fever produced observable tissue damage in the heart, intestine, kidney and liver. No tissue damage could be found in the brain or skeletal muscle. In three experiments cardiac index reached a maximum at approximately 43°C rectal temperature and then fell as the temperature was increased.
Effects of hemorrhage and hypoxia on febrile dogs and monkeys
Authors: Kubicek W. G. , Anderson W. D.
Published: December 2017

Studies were made with: a) hemorrhage held constant and blood pressure variable; b) hemorrhage variable and blood pressure held constant. The average effects of hemorrhage during fever were: an increase in rectal temperature (fever), a decrease in blood pressure, an increase in pulse rate, an increase in blood sugar, an increase in plasma creatinine, no change in plasma chloride, a slight decline in blood pH, a decrease in blood CO2 content, no change in blood O2 content, no change in hematocrit and no change in O2 consumption rate. The average effects of hypoxia superimposed upon fever plus hemorrhage were: little, if any, change in rectal temperature and, in some cases, a circulatory collapse resulting in an autotransfusion. Pulse rate increased slightly. The blood sugar changes were variable, with an increase in some experiments and a decrease in others. Plasma creatinine, plasma chloride, blood pH, blood CO2 content, hematocrit and sedimentation rate changed little, if any. The blood O2 content and oxygen consumption rate decreased.
Chromatolysis and vacuolation of specific diencephalic nuclei induced by acute pyrexia
Authors: Brody Harold , Rodbard Simon
Published: December 2017

To determine the effects of high body temperature upon cells of the central nervous system, chicks were exposed to radiant heat. An increase in body temperature 3°C above normal resulted in chromatolysis and vacuolation in the cells of the nucleus rotundum, the nucleus entopeduncularis inferior and nucleus anterior medialis of the hypothalamus. A decrease in body temperature 15°C below normal had no effect upon these cells. It is suggested that the nuclei affected by the induced acute pyrexia may be involved in sensing and responding to the specific thermal overload.
Potassium and sodium content of uterine and seminal vesicle secretions
Authors: Howard Evelyn , De Feo Vincent J.
Published: December 2017

K and Na concentrations of the fluid which accumulates in the uterine lumen of the rat during proestrus were studied before and after the animals were mated. The K in the resting uterine secretion was 37, the Na 115 mEq/l. The sum of the K plus Na in the resting uterine secretion did not differ from the sum of the K plus Na in serum samples obtained simultaneously. The seminal vesicle secretion of the rat contained 1.1 mEq/l. of K and 34 of Na. The fluid obtained from the uterine lumen after mating with a vasectomized male did not show a significant reduction in K, but the Na concentration was reduced 11%. The high K/Na ratio found in the rat uterine fluid is similar to the K/Na ratios reported by others for the seminal plasma of several mammals.
Effect of trimethylamine and its homologues on renal conservation of trimethylamine oxide by the spiny dogfish, Squalus acanthias
Authors: Cohen Julius J. , Krupp Marcus A. , Chidsey Charles A. , Biltz Charles I.
Published: December 2017

In renal clearance experiments with dogfish, trimethylamine HCL (TMA) administration (i.m.) results in a large increase in trimethylamine oxide (Oxide) excretion. This is shown to occur by inhibition of net renal tubular reabsorption of the Oxide. The TMA, on the other hand, reaches the urine by net tubular secretion in quantities which are consistent with the attainment of diffusion equilibrium across the pH gradient between urine and plasma. The effect of TMA is not related to increased urine flow but is a specific effect on Oxide reabsorption. The administration of the homologue of TMA, dimethylamine, results in a similar but less profound blockade of Oxide reabsorption. Methylamine, however, has no effect at all on Oxide reabsorption. Large excretory losses of TMAO occurred without any change in TMAO plasma level, further indicating the physiological regulation of the plasma concentration of this weak base.
C14 studies in carbohydrate metabolism: glucose pool size and rate of turnover in the normal rat
Authors: Baker N. , Shipley R. A. , Clark R. E. , Incefy G. E.
Published: December 2017

The curve of decline of specific activity after an intravenous injection of C14 glucose in rats consists of at least three components. Because extrapolation of the third portion of the curve (subsequent to 1 hr.) gives a value for glucose space which appears to be spuriously high, the rate of glucose disposal calculated therefrom is also likely to be in error. Assumption that the total curve is formed from the composite effect of mixing, recycling via nonglucose carbon, and irreversible glucose disposal permits construction of a compatible physiological model. Glucose pool size and rate of irreversible disposal calculated by mathematical treatment of this model may then be approximated. Calculations indicate that glucose space in the rat is approximately 20% of body weight. Irreversible disposal (oxidation plus synthesis to fat, etc.) is in the vicinity of 0.6 mg/min. for fasted rats and 1 mg/min. for postabsorptive rats. Total turnover time of plasma glucose is approximately 2–3 minutes. Combined glucogenesis and gluconeogenesis seem to proceed more rapidly in the postabsorptive state than during fasting.
Metabolic relationship of exogenous phospholipids and phosphate to biliary phospholipids
Authors: Nakayama Fumio
Published: December 2017

To study the metabolic relation between exogenous phosphorus and biliary phospholipids, P32-orthophosphate and P32-labeled phospholipids were injected into the duodenum through the distal end of the severed common duct of the rat while bile was collected from the proximal end of the severed duct. Following the administration of biosynthesized P32-labeled phospholipids, P32 appeared in the bile within 3 hours, reached a maximum concentration in about 6 hours and then decreased gradually. About 5–6% of the total absorbed radioactivity was recovered. Following the administration of labeled orthophosphate, P32 appeared in the bile more rapidly, within 30 minutes, and reached a maximum concentration after about 4 hours. Specific activity of organic phosphorus in bile reached its peak from the 4th to the 12th hour. About 2% of the total absorbed radioactivity was recovered. Following the administration of radioactive bile obtained from rats given high radioactive inorganic orthophosphate intraperitoneally, the pattern of P32 excretion in bile was similar to that of P32-labeled phospholipids administration. After intravenous administration of labeled phospholipids with sodium cholate as an emulsifer, P32 appeared in the bile immediately.
Olfactory bulb potentials evoked by electrical stimulation of the contralateral bulb
Authors: Walsh Raymond R.
Published: December 2017

A single, short-duration electrical stimulus delivered to one olfactory bulb evokes a potential in the contralateral bulb. As recorded with a unipolar electrode, the potential is negative central to, and positive peripheral to the external plexiform layer. Bipolar recordings from multiple sites show that the potential is not actively propagated. The potential summates in response to tetanic stimulation and is blocked by anoxia and dimethyl ether d-tubocurarine. In addition to confirming the existence of an interolfactory bulb system, the electrophysiological evidence in conjunction with known anatomical relationships strongly suggests that the evoked potential is a postsynaptic potential of the internal granular cells.
Cardiac output of the hypothermic rat
Authors: Bullard Robert W.
Published: December 2017

As the colonic temperature of the rat was lowered the heart rate and cardiac output fell linearly with the temperature. The arterial pressure did not fall linearly indicating an increase of total peripheral resistance. The increase of hematocrit ratio and the effect of cold on blood per se combined to increase the in vitro viscosity threefold as the colonic temperature approached 15°C. It appears from these data that the increase in viscosity of the blood is the important factor in the increase in total resistance to flow and that little change in total or average vascular geometry took place. However, comparison of the local clearances of 1131 from specific extravascular areas shows that individual vascular geometries may be changing but in such a fashion as to balance out each other.