bluuebunny/crossref_metadata_2025 huggingface dataset:
Water Exchange in Dogs Following Partial Section of the Pituitary Stalk
Authors: Campagna Mario J. , Dodge Henry W. , Clark Edward C.
Published: December 2017

After a preliminary observation period, a small lesion was made in the pituitary stalk of 10 dogs. The daily water intake, urinary output, urinary specific gravity and body weight were recorded. Each animal was given water-load tests consisting of a large volume of tap water by gavage. The surgical lesions were verified histologically. Immediately following the surgical procedure there was a marked spontaneous increase in water intake and urinary output lasting approximately 3 days. Each animal subsequently passed through a period of water retention as shown by the water-load test at some time between the 6th and the 10th postoperative day. Following this, the water exchange and the response to the water-load test approximated the preoperative values. The possible physiologic significance of these findings is discussed.
Respiratory Influence on the Vasomotor Center
Authors: Tang Pei Chin , Maire Frederick W. , Amassian Vahe E.
Published: December 2017

Respiration, blood pressure, and splanchnic and phrenic discharges were recorded from cats (anesthetized with chloralose, immobilized with Syncurine and artificially ventilated) under conditions of asphyxia, vagotomy, hyperventilation and pneumothorax. The results indicate a close relationship between the vasomotor and respiratory center. Both the respiratory center and ventilation can influence the vasomotor center. The ventilatory influence is exerted through blood pressure changes synchronous with respiration. Although unaffected by decerebration, respiratory grouping of splanchnic discharge was completely abolished by spinal transection at C1, and is probably controlled by the medullary vasomotor center. Since sinus denervation and vagotomy did not abolish respiratory grouping of splanchnic discharge, blood pressure changes can affect the vasomotor center through mechanisms other than sino-aortic reflexes. The difference between positive and negative pressure breathing in effecting the respiratory influence on the vasomotor center is discussed.
Vagal Gastric Secretory Nerves in the Rat Demonstrated With Insulin
Authors: Lane Ardelle , Ivy A. C. , Ivy E. K.
Published: December 2017

It was found in four tests on each of 12 rats with a chronic gastric fistula and accustomed to the experimental procedures that insulin hypoglycemia short of convulsions stimulated gastric secretion when the vagus nerves were intact. In five tests on each of seven rats, it was found that section of the vagi abolished the secretory response to insulin hypoglycemia. This evidence is interpreted as establishing the presence of gastric secretory nerves in the vagi of the rat.
Effects of Androgenic Hormones on the Rate of Incorporation of Labeled Amino Acids in Male Adult Mice
Authors: Novak Alfred
Published: December 2017

Measurements of radioactivity were made on various tissues of the male mouse and the rates of in vivo incorporation of various radioactive amino acids into proteins were determined in intact, castrated, and male hormone-treated castrated mice. Using the rate of incorporation of radioactive amino acids into protein tissue as a criterion for protein metabolism, male hormones at physiological dosages produced no significant protein anabolic effect in visceral and muscle tissues of the mice studied. As a general rule, the castrated mice incorporated more radioactive amino acids than intact animals. Incorporation of radioactive histidine however in longer time periods appeared to follow a somewhat different pattern, i.e., the male hormone showed a stimulating action in both intact and hormone-treated castrates.
Aldosterone Excretion in Urine From Hypophysectomized Dogs With Thoracic Inferior Vena Cava Constriction
Authors: Davis James O. , Bahn Robert C. , Goodkind M. Jay , Ball Wilmot C.
Published: December 2017

Effects of hypophysectomy on aldosterone and sodium excretion were studied in a group of seven dogs with ascites secondary to thoracic inferior vena cava constriction. In another group of three dogs, the pituitary was removed first and after 6–8 weeks the thoracic inferior vena cava was constricted. Following hypophysectomy of the seven dogs with the initial ascites, aldosterone became undetectable in urine and sodium excretion increased concurrently; adrenocorticotrophic hormone (ACTH) failed to prevent these effects. However, additional constriction of the vena cava with a consequent further elevation in venous pressure was followed by a return of nearly complete sodium retention. In two of the dogs in which hypophysectomy was performed first and the thoracic inferior vena cava constricted later, there resulted increased aldosterone output, marked sodium retention and ascites. In these dogs the adrenal cortex was markedly atrophic but the atrophy was limited to the two inner layers. The data suggest that in pathological states accompanied by edema and ascites the increased excretion and presumably increased secretion of aldosterone are not solely dependent upon pituitary hormonal function.
Effect of Bilateral Nephrectomy on Urea Formation in Rat Liver Slices
Authors: Sellers Alvin L. , Katz Joseph , Marmorston Jessie
Published: December 2017

The rate of urea synthesis by isolated liver slices has been determined. The rate of urea synthesis is approximately 50% greater in liver slices from nephrectomized rats than in those from nonuremic controls. Liver slices from intact rats maintained on a diet of 15% glucose formed only 23–50% as much urea as slices from fasted controls. The results indicate that the increased urea synthesis in liver slices from nephrectomized rats is largely due to an increase in the catabolism of liver protein resulting in an increase in urea precursors.
Effects of Acute Changes in Acid-Base Balance on Renal Calcium Excretion in Dogs
Authors: Williamson Billy James , Freeman Smith
Published: December 2017

The effects of acute disturbances in acid-base balance on renal cation excretion were studied in dogs. Special attention was given to the excretory mechanism for calcium. Four different states were produced experimentally: respiratory acidosis, metabolic acidosis, metabolic alkalosis and compensated metabolic alkalosis. Additional experiments were carried out in normal and alkalotic animals subjected to calcium loading. Calcium reabsorption was found to vary directly with the filtered load of calcium. The increased excretion of calcium in acidosis appears to be due to an increase in filtered calcium. The percentage of reabsorption of filtered calcium was 98–99% in normal and acidotic dogs, but decreased to approximately 90% in animals made acutely alkalotic. However, the relative loss of water to calcium in the urine in acute alkalosis was decreased, resulting in an elevated renal threshold of retention of calcium in metabolic alkalosis. Data are included on the behavior of inorganic phosphate in the various states studied. Elevated carbon dioxide tension was associated with phosphate mobilization from the tissues regardless of whether or not the carbon dioxide excess was compensated for by extra alkali.
Relation Between Amplitude of First Heart Sound and Duration of P-Q Interval in Dogs With Atrioventricular Block
Authors: Siecke Helmut , Essex Hiram E.
Published: December 2017

Curves that relate the amplitude of the first heart sound to the P-Q interval have been obtained in 13 dogs with complete atrioventricular (AV) heart block. The amplitude was highest at a P-Q interval of approximately 0.05 second, became lowest at a P-Q interval of 0.13 second and continued low for intervals up to 0.25 second or longer and then increased again to some extent with further prolongation of the P-Q interval. Cardiac failure or infusions into peripheral or pulmonary veins caused an earlier and higher rise of the amplitude with very long P-Q intervals, whereas exsanguination had the opposite effect. These factors probably alter reopening of the AV valves during atrial diastole and thereby change the intensity of the first heart sound.
Prevention of Congestive Heart Failure in Rabbits With Severe Aortic Constriction
Authors: Alexander Natalie , Drury Douglas R.
Published: December 2017

A severe aortic constriction induces hypertension followed by death from congestive heart failure within 8 days in the majority of rabbits. The present study was planned to find out if previous successful cardiac adaptation to moderately elevated pressure could prevent congestive heart failure or prolong survival time following severe aortic constriction. A three-stage operative procedure was used to vary the cross-sectional area of the aorta. A moderate degree of aortic constriction was induced for 4 or 7–13 (average 10) days during which time arterial pressure rose. The constriction was removed, pressures fell to within normal limits after 3–7 days and then the severe aortic stricture was applied. The presence of elevated pressure for more than a week after moderate constriction protected six of seven animals from the heart failure inducing effects of a severe aortic stricture. The seventh animal developed heart failure and died after 24 days. After less than a week of elevated pressure, survival was prolonged to 21–27 days in three of four animals, and heart failure was prevented in the fourth animal. At no time was bradycardia observed and sometimes high heart rates occurred when pressure reached new high values after the severe stricture. The pressure suddenly dropped for short periods in several animals, but they retained their ability to develop high pressure; something never observed in animals with no previous pressure elevation.
Water and Sodium Excretion in Hormonally Hypertensive Rats
Authors: del Greco F. , Masson G. M. C. , Corcoran A. C.
Published: December 2017

Osmotic diuresis with mannitol was used as a means of evaluating renal water and sodium reabsorption in uninephrectomized normotensive rats ( I) and in rats made hypertensive by adrenal enucleation ( II), and by injection of desoxycorticosterone acetate ( III), cortisone ( IV) or both hormones ( V). All the hypertensive rats showed a diminished capacity for water reabsorption, tentatively attributed to potassium depletion. Sodium excretion patterns were not related to arterial pressure in any group, nor to glomerular filtration rate in groups I, III, IV and V. Rats with regenerating adrenals ( II) showed some impairment of ability to retain Na during osmotic diuresis.
Influence of Testosterone, Methyltestosterone and dl-Ethionine on Canine Liver Lipids, Serum Lipids and Lipoproteins
Authors: Furman Robert H. , Norcia Leonard N. , Robinson Charles W. , Gonzalez I. Ernest
Published: December 2017

Methyltestosterone, testosterone or dl-ethionine administration to dogs causes marked reduction in high density -S1.21 0–20 (alpha) lipoproteins. Lower density -S1.21 25–40 or 40–70 (Sf 12–20 or 20–100 or beta) lipoproteins are not found in sera from healthy dogs and therefore cannot increase in amount during androgen administration, as is often the case in human subjects. In the dog, reduction in -S1.21 0–20 serum lipoprotein levels therefore is accompanied by reduced levels of serum cholesterol and phospholipid. The liver total lipid, cholesterol and lipid phosphorus values did not change, in spite of marked changes in serum values, after testosterone or dl-ethionine administration. Our failure to find fatty livers in the dogs fed dl-ethionine may be attributable to the fact that the animals were not force-fed. Since androgen appears to protect many species against fatty liver induced by dl-ethionine, presumably by a protein-sparing action, it is suggested that the reduction in canine serum lipids and lipoproteins induced by dl-ethionine and androgens must result from either a) different mechanisms, or b) if a common mechanism, then one not involving ‘protein metabolism’ per se.
Brain Acetylcholinesterase and a Respiratory Reflex
Authors: Metz Bernard
Published: December 2017

Experiments were carried out to determine the correlation, if any, between the level of acetylcholinesterase (AChE) activity in the brain and the degree of respiratory reflex potentiation and inhibition which occurs after the administration of varied doses of an anticholinesterase, tetraethyl pyrophosphate (TEPP). After a steady state of reflex response was reached (elicited by electrical stimulation of Hering's Nerve), TEPP was injected in varying doses via a cisternal puncture, and the anesthetized dogs were killed at various stages of reflex potentiation and inhibition. Analyses of the AChE activity of representative brain areas indicated that following an initial marked potentiation, maximal at AChE values approximately 84–88% of the controls, there is a gradual but progressive decline in the potentiated respiratory reflex which parallels the fall in the AChE activities of the brain areas vitally concerned with respiration, until respiratory failure was evident when the enzyme activity was 8–11% of the control values. These experiments lend suggestive evidence that a neurohumoral component (e.g. acetylcholine) may be factor in respiratory control.
Effect of Stretch on Formation and Conduction of Electrical Impulses in the Isolated Sinoauricular Chamber of Frog's Heart
Authors: Pathak C. L.
Published: December 2017

The influence of stretch due to increased intraluminal pressure on the formation and conduction of electrical impulse was studied electrocardiographically in 12 isolated sinoauricular chambers of frog hearts perfused with frogs' Ringer. The impulse frequency was found to be directly proportional to the degree of intraluminal perfusion pressure up to a certain critical head of pressure (2–6 cm Ringer), beyond which the impulse frequency declined. At higher pressures the electrogram showed a diminished amplitude of the action potential and broadening and notching of sinus waves and auricular complexes. The duration and conduction velocity of electrical impulse was increased.
Effect of Epinephrine on the Rate of Urine Formation
Authors: Langston Jimmy B. , Guyton Arthur C.
Published: December 2017

It is concluded that epinephrine and norepinephrine affect urine formation in two ways: first, by increasing the arterial pressure which indirectly increases urinary output, and, second, by acting directly on the kidney to decrease the output. When the arterial pressure was held constant only the direct effect was evident. The results of other workers showing that there is no distinguishable difference in the actions of epinephrine and norepinephrine on the kidney were confirmed.
Cellular Sites of Hepatic Ferritin Activation and Inactivation
Authors: Baez Silvio , Srikantia S. G. , Carleton Anne
Published: December 2017

Studies with viable reticulo-endothelial (RE) and parenchymal cells separated from the liver show that the parenchymal cells contain most of the liver ferritin. This ferritin is vasoinert, and anaerobic incubation of the parenchymal cells does not release it in vasoactive form. Aerobic parenchymal cells readily inactivate exogenous vasoactive ferritin. Parenchymal cells isolated from the liver of normal rats subjected to traumatic shock contain vasoactive ferritin and have lost their ferritin inactivating capacity, whereas those from resistant rats subjected to the same trauma contain only vasoinert ferritin and are still able to inactivate added ferritin. On the other hand, RE cells contain smaller amounts of vasoinert ferritin but readily release it in vasoactive form on anaerobic incubation. RE cells are not able to inactivate exogenous ferritin. When a small amount of a vasoinert, clear extract, prepared from homogenized RE cells, is added to parenchymal cells during anaerobic incubation, the parenchymal cells release their ferritin in vasoactive form. The ‘activator’ obtained from the RE cells has not been identified.
Alloxan Diabetes and Demonstrated Direct Action of Insulin on Metabolism of Isolated Perfused Rat Liver
Authors: Haft David E. , Miller Leon L.
Published: December 2017

The direct effect of insulin was studied in intact surviving livers removed from normal and alloxan-diabetic rats and perfused for 4 hours with rat blood containing acetate-1-C14. Changes due to diabetes per se were a) decreased lipogenesis from acetate, b) increased ureogenesis, and c) increased incorporation of acetate into carbohydrate. The positive effects of insulin consisted of an at least partial correction of the depressed lipogenesis characteristic of diabetes and of fasting, and a net removal of glucose from the perfusate after the 1st hour. The action of insulin was inhibited in most of the experiments with ketotic liver donors, and also in many experiments in which the operative procedure was accompanied by excessive trauma. Insulin administration depressed gluconeogenesis from acetate and lowered ketogenesis in experiments with alloxan diabetic donors.
Transport Through the Rabbit Oviduct
Authors: Black D. L. , Asdell S. A.
Published: December 2017

Longitudinal contractions of the rabbit oviduct do not change in amplitude or rate at different intervals after mating to 4 days, but they become greater in pregnancy and less in pseudopregnancy. Oil and India ink are spread in both directions by segmentation and pendular movement of the smooth muscle but they are arrested at 2–3 cm anterior to the tubo-uterine junction unless more than 0.1 ml is used. Paralysis of the muscle with nicotine prevents movement. When a plastic tube is inserted through the tubo-uterine junction, passage of ova past the critical zone is hastened. Ligature of the infundibular end of the oviduct causes distension, so that oviduct secretions must normally pass through the infundibulum and not into the uterus. This probably aids the transport of spermatazoa while ova are kept from escaping in this direction by the cilia and by the mucosal folds.
Comparative Inhibition of Anaphylaxis in Mice by Steroids, Tranquilizers and Other Drugs
Authors: Fox Charles L. , Einbinder Julia M. , Nelson Carl T.
Published: December 2017

The physiological mechanisms involved in anaphylaxis were further investigated by studies of drugs with adrenolytic, hypertensive, vasoconstrictive action, also tranquilizers and antihistaminics, diuretics, anti-inflammatory agents and newly available steroids. Mice were sensitized with normal horse serum. All drugs were administered prior to challenge and protection gauged by survival of sensitized mice compared with incidence of fatal anaphylaxis in untreated sensitized mice. Compounds exerting maximum protection were chlorpromazine, promazine, reserpine, lysergic acid diethylamide, prednisolone, prednisone, fluorohydrocortisone, hydrocortisone and cortisone. Inactive compounds were meprobamate, sedatives and antihistaminics, inflammatory agents, diuretics and predominantly sodium-retaining steroids.
Effects of Insulin and Activity on Pentose Transport Into Muscle
Authors: Sacks Jacob , Smith Jolynn F.
Published: December 2017

The effects of insulin and muscular activity on the transport across the cell membrane of muscle of pentoses having the same steric configuration about carbon atoms 1, 2 and 3 as d-glucose has, were found to be additive in the nephrectomized cat. The degree of intracellular penetration of l-arabinose into muscle was found to be related to the extent of activity. The results suggest that the effect of muscular activity on pentose penetration is not due to a humoral agent. They also suggest that insulin and muscular activity exert their effects by different mechanisms.
Effects of Xanthine Diuretics on Renal Tubular Transport of PAH and Glycine Conjugation of PABA
Authors: Huang K. C. , King N. B. , Genazzani E.
Published: December 2017

In renal cortical slices, methylated xanthine diuretics caused a reduction of PAH uptake to 50–70% of the control values with a slight increase in O2 consumption; xanthine, hypoxanthine, guanine and adenine had little effect. Among the three methylated xanthine derivatives studied, 1,3 dimethylxanthine ethylenediamine (Aminophylline) was found to have more inhibitory effect than the others. This inhibitory effect was a function of the concentration of the compound in the medium and cannot be reversed by addition of glutathione as is the case with mercurial diuretics. The potassium exchange between cells and medium and the glycine conjugation of PABA to PAH by the tubular cells were not significantly affected in the presence of aminophylline. The mechanism of the action is discussed and it is postulated that aminophylline or the other methylated xanthine compounds increase the membrane permeability of renal tubular cells, allowing more PAH to leak out.
Distribution in Renal Cell Fractions of Sulfhydryl Groups in Rats on Normal and Sucrose Diets and Its Relation to Renal Mercury Distribution After Mercuric Chloride Injection
Authors: Surtshin A. , Yagi Koichi
Published: December 2017

Most rats fed a diet of sucrose and vitamins for 3 or more weeks survive intravenous injection of mercuric chloride, 3 mg/kg, a dose uniformly lethal to rats on a normal diet. It is found that the sulfhydryl content of the ‘soluble’ fraction obtained from kidney by means of the centrifuge is greater in sucrose-fed than in chow-fed rats. Three hours after injection of mercuric chloride the sucrose-fed as compared with the chow-fed rat shows the same total mercury content in kidney, but a much higher content in the ‘soluble’ fraction and much lower contents in the ‘nuclear’ and ‘granular’ fractions. The increase in resistance to the toxicity of mercuric chloride seen in sucrose-fed rats may be related to a decrease in the binding of mercury by sulfhydryl groups of the renal nuclei and mitochondria. Severe protein depletion may be causally involved in producing the state of increased resistance.
Effect of Nicotine on the Synapse of the Central Nervous System
Authors: Takagi Sadayuki F. , Oomura Yutaka
Published: December 2017

The effect of nicotine on synaptic transmission in the frog and cat spinal cord was studied. Both a regular wick electrode and a microelectrode of the Ling-Gerard type were used. The reflex activity of the bullfrog spinal cord is facilitated by 0.01% nicotine solution, but is depressed and abolished by 0.1% solution. In the cat, intravenous administration of 150 mg/kg fails to block reflex activity, but topical application does block. The intracellular potential, of both frog and cat motoneurones, shows no change in the synaptic potential after application of the drug, but the spike appears after a shorter synaptic delay and one or more additional spikes appear. When the synaptic delay becomes sufficiently short, however, all spikes suddenly disappear, leaving the still unchanged synaptic potential. Occasionally the synaptic delay is again increased just before the spike potentials disappear. The excitability of a frog motoneurone was measured, by a recording microelectrode, before and after nicotine application. The drug first increased and then decreases excitability. Epinephrine can restore a reflex discharge depressed or abolished by nicotine. It is concluded that high concentrations of nicotine block synaptic transmission in the central nervous system, acting on the cell body but not on the synaptic potential.
In Vitro Effects of Carbutamide and Tolbutamide on Isolated Frog Muscle
Authors: Gourley D. R. H. , Dodd R. H.
Published: December 2017

Carbutamide and tolbutamide, sulfonylurea compounds which reduce the blood glucose concentration in intact animals, do not act like insulin in isolated frog muscle. Carbutamide, like sulfanilamide, inhibits the consumption of oxygen and increases the loss of potassium from the muscle. Tolbutamide greatly increases the oxygen consumption and decreases the loss of potassium from the tissue. These effects of tolbutamide are accompanied by a loss of muscle glycogen and an accumulation of lactate. Since the effect of tolbutamide on oxygen consumption can be inhibited with sodium azide, the extra oxygen is presumably used to oxidize the accumulating lactate and energy is thus provided to increase the influx of potassium into the tissue.
Influence of Insulin on Protein Metabolism and Cardiac Glycogen in Houssay Animals
Authors: Lukens F. D. W.
Published: December 2017

The urinary nitrogen excretion of hypophysectomized-depancreatized (Houssay) cats on constant diets was measured before and during the administration of insulin. Metabolic periods of 4–8 days were used. Nitrogen retention occurred in the absence of the anterior pituitary, when urinary glucose was reduced by 5 gm or more during insulin treatment. Otherwise, retention of nitrogen did not occur. Conventional calculation of the total utilization of glucose for these and control groups of animals suggest that the amount of change in glucose utilization and secondary hormonal effects exert more influence on protein metabolism than the actual amount of carbohydrate used. Restoration of hepatic tissue (protein) was grossly demonstrable. In animals lacking insulin, the anterior pituitary, or both, cardiac glycogen appeared to be significantly related to the level of blood glucose.
Kinetics of Distribution of D2O and Antipyrine in Isolated Perfused Rat Liver
Authors: Thompson Alan M. , Cavert H. Mead , Lifson Nathan
Published: December 2017

Isolated rat livers were perfused via the portal vein with a blood-Ringer mixture containing a constant inflow concentration of D2O and, in some cases, antipyrine. The rate of increase of outflow concentration was studied, comparisons being made between D2O, antipyrine and a theoretical outflow curve based on completely flow-limited distribution. The effect of flow rate on the deviation of D2O from theoretical was also studied. The results indicate that exchange of D2O and antipyrine between blood and tissue in the perfused rat liver is extremely rapid relative to the rate of blood supply of these substances to the organ, even at flows several times that occurring in vivo. In the average experiment the average D2O concentration in the liver during the early period of the perfusion was about 90% of the mixed venous concentration. The factors responsible for the failure of D2O to distribute maximally, particularly tissue perfusion heterogeneity and diffusion limitation, are discussed. Although quantitation of the difference is difficult, antipyrine appears to distribute somewhat more rapidly than D2O due to its greater solubility in cell membranes.
Regeneration of Hemoglobin in Rats Exposed to Low Ambient Temperature
Authors: Šimonović Ivan , Šlat Blanka , Kostial Krista
Published: December 2017

Rats kept at low ambient temperature (5°C) for 20 days showed on the 2nd and the 5th day of exposure slightly lower hemoglobin values than the control animals kept at room temperature. The rate of hemoglobin regeneration after acute bleeding (30% of the total amount of blood lost) in rats exposed to low temperature was approximately the same as in rats kept at room temperature.
Effect of Exposure to Cold on the Islets of Langerhans in the Rat
Authors: Baker D. G. , Ashworth M. A.
Published: December 2017

The amount of insulin extractable from the pancreas of rats was decreased by exposure to cold (1.5°C) for a period of 50 days. The weight of the pancreas was increased by exposure to cold. Changes in the weight of the Islets of Langerhans were so variable that no statistically significant variation was observed. Prolonged exposure to cold did not affect the concentration of blood lactic acid.
Venous Pressure and Total Peripheral Resistance in the Dog
Authors: Read Raymond C. , Kuida Hiroshi , Johnson John A.
Published: December 2017

The techniques of total body perfusion have been applied to the problem of the influence of venous distension on resistance to blood flow. The results obtained support the classical view that a rise in venous pressure leads to a fall in total peripheral resistance. The possibility of a venivasomotor constrictor reflex occurring in certain parts of the circulation was not excluded by these studies.
Effects of 2,4-Dinitrophenol on Respiration in the Dog
Authors: Williams T. Franklin , Winters Robert W. , Clapp James R. , Hollander Walter , Welt Louis G.
Published: December 2017

The intravenous administration of 2,4-dinitrophenol (DNP) to unanesthetized or anesthetized dogs produced an increase in arterial pH and decrease in arterial Pco2 which preceded any significant rise in body temperature. Thus the hyperventilation associated with DNP-administration appears not to be solely the result of increased production of CO2. Although DNP in small amounts stimulated respiration via the carotid body, larger doses still produced increased ventilation and pH and decreased Pco2 after denervation of the carotid bodies and bilateral vagotomy, thus demonstrating a stimulatory effect of DNP at some more central site as well. DNP increased the sensitivity of the respiratory center (or its afferent connections) to Pco2 and/or concentration of hydrogen ion. The similarities of respiratory effects of DNP and salicylate are discussed. An unexplained increase in ‘buffer base’ of the blood occurred in association with the respiratory alkalosis induced by DNP.
Kinetics of the Negative After-Potential in Frog Single Nerve Fibers
Authors: Schoepfle Gordon M. , Bloom Floyd E. , Hellam Duane
Published: December 2017

The time course of the negative after-potential from an isolated single nerve fiber is adequately described by the sum of two exponential terms. Conductance changes are confined to the relatively brief initial phase. The difference between active and resting membrane potential bears a relation to over-all membrane resistance which is consistent with the view that the first phase of the negative after-potential is dependent on a change in potassium conductance. The prolonged terminal phase of the after-potential is characterized by an exponential time constant identical with that of the slow drift in membrane potential (slow component of electrotonus) associated with the break of an anodal pulse. Both magnitude and time parameter of this terminal phase vary with pre-existent membrane potential. The differential changes in magnitude of spike and after-potential resulting from changes in pre-existent membrane potential suggest that the effects of anoxia on the after-potential/spike ratio are dependent only on the change in membrane potential.
Localization of Lesions in the Lateral Hypothalamus of Rats With Induced Adipsia and Aphagia
Authors: Morrison Seoras D. , Barrnett Russell J. , Mayer Jean
Published: December 2017

A detailed examination was made of the areas damaged in animals exhibiting aphagia and adipsia following electrolytic lesions placed in the lateral hypothalamic and sub-thalamic areas with the use of a stereotaxic instrument. This study strongly suggests that the median forebrain bundle may be as important as the lateral area proper in the control of food and water intake. A similar conclusion is also suggested by the localization of areas of destruction in the midbrain of animals showing prolonged aphagia and adipsia following a ‘sham operation’ involving placement of needle electrodes without passage of current.
Uptake of Cholesterol and Cholesterol Esters by Inverted Sacs of Rat Intestine
Authors: Smith Archie L. , Hauk Rosalind , Treadwell C. R.
Published: December 2017

Conditions for the use of inverted sacs of rat small intestine for the study of the mechanism of cholesterol absorption are described. Incubation of inverted sacs in albumin-stabilized emulsions of free cholesterol or cholesterol esters, under oxygen-carbon dioxide mixture, led to the disappearance of cholesterol from the external medium and accumulation of free or ester cholesterol in the sacs. Both forms of cholesterol were taken up against a concentration gradient without demonstrable chemical change. The uptake of free cholesterol was quite constant from the lower duodenum to the upper ileum and was independent of the pH of the external medium. Additions of oleic acid, sodium taurocholate or pancreatic extract depressed the uptake of free cholesterol. Comparable but more variable effects were found in respect to cholesterol ester uptake. Addition of pancreatic extract to the external medium increased the proportion of ester in the total cholesterol taken up by the sacs. This was due, in part, to synthesis of cholesterol esters in the mucosa.
Effects of Antecedent Food Intake Pattern on Hepatic Lipogenesis
Authors: Tepperman Jay , Tepperman Helen M.
Published: December 2017

Liver slices of ATG obese mice, of rats trained to eat their 24-hour ration in 1 hour and of rats fed a high carbohydrate diet after a 48-hour period of fasting were incubated with acetate-1-C14 and with glucose-U-C14 and the extent of incorporation of the precursor label in the fat fraction was measured. Comparatively high rates of lipogenesis were observed in all three circumstances, the highest in the ‘refed’ group. A high positive correlation was found between initial glycogen content and lipogenic performance of the slices. A high rate of glucose absorption from the g.i. tract was noted in the ‘trained’ animals. A three to fourfold increase in TPN-linked hexose monophosphate shunt dehydrogenase activity was found in preparations from the livers of ‘refed’ rats. The problem of ‘supernormal’ lipogenesis is discussed in the light of recent studies on the ‘failure’ of lipogenesis associated with diabetes and carbohydrate deprivation and the possible significance of a fluctuating supply of TPNH as a central mechanism in the adaptation and de-adaptation of the lipogenic apparatus is reemphasized.
Effect of Cobra Venom on Leucocytes
Authors: Khalil Fouad , Abou-El-Naga Ibrahim , Riad Zakia Mohammad
Published: December 2017

Intermittent injections of sublethal doses of the venom of Naja haje of Egypt caused temporary leucopenia followed by leucocytosis in guinea-pigs and rabbits. There was always a rise in the percentage of neutrophil leucocytes and a corresponding drop in the percentage of lymphocytes. The leucocytes of both types of animals exhibited morphological signs of phagocytosis and degeneration.
Discrete Threshold and Repetitive Responses in the Squid Axon Under ‘Voltage-Clamp’
Authors: Tasaki I. , Bak A. F.
Published: December 2017

By using the so-called voltage-clamp technique, records were obtained indicating the presence of undulatory or oscillatory membrane current under fixed potential difference between the internal and external electrodes. This oscillatory membrane current was observed only when rectangular membrane depolarization was in the range between 15 and about 35 mv. The amplitude of the oscillatory membrane current was of the order of 1 ma/cm2. The oscillatory membrane current disappeared suddenly when the depolarizing clamping pulse was reduced below the ‘threshold.’ Various sources of artefact were examined.
Nonuniform Response in the Squid Axon Membrane Under ‘Voltage-Clamp’
Authors: Tasaki I. , Spyropoulos C. S.
Published: December 2017

By cooling a portion of the squid giant axon at a time, it was shown that the repetitive membrane currents observed under the so-called voltage-clamp conditions derived from the main portion of the ‘clamped’ axon membrane and not from the lateral unclamped portion. An improvement of the guard system by the use of the method of ‘double voltage-clamp’ also supported this conclusion. Using a microelectrode introduced through the axon surface, it was found that, when the clamping level was between 20 and 35 mv, some part of the membrane became fully active while other parts remained at rest. In this range of membrane depolarization, the active area was found to increase with increasing depolarization. It was stressed that spatial nonuniformity of the squid axon membrane has to be taken into consideration in the interpretation of the results of so-called voltage-clamp experiments.
Hypothalamic Responses During and Following Occlusion of Cephalic Vasculature in the Cat
Authors: Costantin LeRoy L. , Wang S. C.
Published: December 2017

Classical anemic decerebration in the cat resulted in variable changes in muscle tone and pupillary size. In some animals the light reflex and blood pressure responses to hypothalamic stimulation were observed to persist for significant periods of time. These results indicate that the method is not reliable in obliterating the blood supply to the rostral brain stem. More thorough ligation of cerebral vessels was shown to produce a much greater degree of success as shown by the uniformly prompt increase in extensor tone and pupillary size and the rapid disappearance of light reflexes and hypothalamic responses. The recovery of hypothalamic activity subsequent to periods of almost complete ischemia as long as 1 hour suggests that the region is very resistant to irreversible change if even a small fraction of its normal blood supply is maintained.
Effect of X-Ray Irradiation on Muscle Fatigue in Rats
Authors: Haley Thomas J. , Flesher A. M. , Komesu N. , McCulloh E. F. , McCormick W. G.
Published: December 2017

With the Ingle fatigue test, it has been demonstrated that a loss of muscle responsiveness, increased fatigability and decreased work output follow acute whole body irradiation. These effects increase with time postirradiation. In both normal and irradiated animals, strain differences were observed. In the dosage used, the administration of adrenal cortical extract did not improve performance. Adrenalectomy plus cortical extract did not improve performance. It has been postulated that the poor performance of the irradiated animals is related to a lack of glycogenolysis, poor intestinal absorption of glucose and circulatory collapse.
Effect of Insulin and Cortisone on Weight Gain, Protein and Fat Content of Rats
Authors: Hausberger F. X. , Hausberger B. C.
Published: December 2017

Male Wister rats weighing 240 ± 2 gm show an average protein and fat content of 41.6 gm, and 13.1 gm. During a period of normal growth, the body weight increases within 14 days to 311 gm, the protein content to 57 gm, and the fat content to 21.7 gm. Several groups of rats were subjected to experimental procedures for 14 days, after having reached a body weight of 240 gm. Administration of protamine zine insulin (12 u/day) greatly enhanced weight gain, and deposition of excess fat, without affecting accumulation of body protein. Cortisone (5 mg/day) produced variable results. Diminished gain of body weight and total body protein occurred in 60% of the animals while accumulation of body fat was normal. Some rats lost weight and body protein but comparatively less fat than animals losing fat due to food restriction. Weight loss was most frequently observed in rats with visible infections. Simultaneous administration of insulin (12 u/day) did not alter the cortisone effect on body protein but markedly increased accumulation of body fat. One hundred twenty units per day accelerated gain of body fat still more. Values were observed comparable to those found in rats receiving insulin only. The amount of total body fat closely paralleled the amount of adipose tissue the composition of which was not significantly altered by any of the hormonal manipulations.
Physiologic Observations on Yellow Obesity in the Mouse
Authors: Carpenter K. J. , Mayer Jean
Published: December 2017

In our colony, yellow obese mice were longer than nonobese littermates and yellow males were heavier than yellow females. Weight gain was greatest on high fat diets. If the yellow mice were given a possibility to exercise (activity cages), they lost weight. Resistance to cold was good. Fasted blood glucose levels were normal, fed levels frequently elevated in males. Yellow male and female mice showed a degree of insulin resistance; yellow males showed a marked hyperglycemic response to growth hormone, ACTH, cortisone, and glucagon. Blood total lipids were elevated in yellow mice, with the females exhibiting hypercholesterolemia. As in other forms of ‘metabolic’ obesity, blood ketones were decreased by an 18 hours fast.
Metabolic and Nutritional Studies in Mice With a Hereditary Myopathy (Dystrophia Muscularis)
Authors: Baker Nome , Tubis Manuel , Blahd William H.
Published: December 2017

Nutritional, chemical and metabolic studies have been carried out on hereditarily muscular dystrophic mice and their littermate controls. Certain characteristics of the dystrophic syndrome which may not have been emphasized previously are described: denudation of the eyelids, periocular inflammation, tremors and an unusual reflex involving the head and neck, inflammation of the penis, and diminished bone growth. The dystrophic mice consumed, on the average, more food per day per unit body weight than their normal controls. Parenteral administration of vitamins A, D, E, the B-complex vitamins and ascorbic acid failed to reverse any of the dystrophic syndrome in eight dystrophic mice. The metabolic rate was normal (per unit weight basis) as measured by the rate of CO2 production; similarily, acetate-1-C14 was oxidized to C14O2 at the same rate in normal and dystrophic mice. Finally, levels of plasma glucose, cholesterol, protein-bound I131, and of liver cholesterol were not significantly different in a small group of normal and dystrophic mice.
Changes in Circulating Plasma and Proteins Following Graded Transfusions in the Dog
Authors: Huggins R. A. , Deavers S. , Smith E. L.
Published: December 2017

A series of dogs was anesthetized with a morphine-pentobarbital combination and the plasma volume measured with radioactive I131 and plasma protein by the method of Barbour and Hamilton. Blood was then transfused in 10 cc/kg increments up to a total of 50 cc/kg. After each 10 cc/kg of blood 20 minutes was allowed for equilibration and then plasma volume and protein were redetermined. No loss of plasma volume or protein occurred with a transfusion of 10 cc/kg, but the loss of both was statistically significant with 20 cc/kg. There was a progressive loss of both plasma volume and protein from the initial values with each additional increment of 10 cc/kg.
Thromboplastin: Nomenclature and Preparation of Protein-Free Material Different From Platelet Factor 3 or Lipid Activator
Authors: Hecht Eugen R. , Cho Min H. , Seegers Walter H.
Published: December 2017

A method was developed for obtaining a highly active fraction from rabbit brain tissue which meets all of the requirements of a complete thromboplastin in the ‘traditional’ sense. The material we have isolated is called brain thromboplastin. This lipid fraction contains no protein. It is a complex consisting of sterol, glutamic acid, serine, ethanolamine and probably sphingosine. These components are also found in lipid activator and in the lipid portion of purified platelet factor 3, the latter being a lipoprotein. It is lethal upon intravenous injection in suitable quantity, while purified platelet factor 3 and or lipid activator are not. When the brain thromboplastin is combined with Ac-globulin and calcium ions, purified prothrombin changes to biothrombin, but such a change to thrombin does not occur when purified platelet factor 3 or lipid activator replaces the brain thromboplastin. For complete transformation of prothrombin to thrombin, it is sufficient to have the following proportions given on a dry weight basis: prothrombin 500, brain thromboplastin 80, and Ac-globulin 1. Heating brain thromboplastin to 100°C for 30 minutes or refluxing it with ether for 90 minutes impairs only very little of its activity but refluxing with alcohol for 90 minutes destroys its activity. However, then the material can still function as a procoagulant. The word ‘thromboplastin’ apparently now is utilized in all kinds of ways so that the meaning is diluted extensively. We use the term more specifically. The terms lung thromboplastin, beef lung extract thromboplastin, brain extract thromboplastin and lipid activator are used in terms of carefully considered descriptions related to preparations. To fulfill the requirements for generic designations, the word procoagulant can refer to all those substances and conditions that further the coagulation of blood while anticoagulant is the opposite designation.
Role of Plasma Accelerator-Globulin and Serum Accelerator-Globulin in Conversion of Prothrombin
Authors: Johnston Betty R. , Jensen H.
Published: December 2017

Either plasma accelerator-globulin or serum accelerator-globulin must be present in order to obtain complete conversion of prothrombin in the presence of serum-eluate factor(s) [proconvertin or plasma thromboplastin component or both], antihemophilic factor, platelet factor 3, and calcium ions. If plasma accelerator-globulin is present, it must first be converted to serum accelerator-globulin by the action of thrombin before the maximum rate of prothrombin conversion is reached. Serum accelerator-globulin does neither affect the degree nor the rate of interaction of serum-eluate factor(s), antihemophilic factor, platelet factor 3, and calcium ions forming a prothrombin-conversion factor but affects thrombin formation at a point just prior to or during the conversion of prothrombin.
Effects of Propylthiouracil on Development and Maintenance of Renal Hypertension in Rats
Authors: Fregly Melvin J.
Published: December 2017

Dietary treatment of rats with propylthiouracil prevented the development of the elevated blood pressure usually accompanying kidney encapsulation with latex envelopes. Within 4 weeks after dietary administration, propylthiouracil also reduced to control levels the elevated blood pressure of rats whose kidneys were encapsulated 9 weeks previously. With regard to dosage, 0.1% PTU appeared to be more effective than 0.06%. This drug (0.1%) also reduced the blood pressure of normal rats. When PTU was administered to growing rats, body weight remained at the level at which administration began. Older rats generally lost weight on the drug, although the extent of weight loss was not consistent among three separate lots of PTU used. The reduction in blood pressure of the ‘encapsulated’ rats could not be attributed solely to the weight loss produced by PTU administration.
Effects of Reserpine on the Fowl
Authors: Sturkie Paul D. , Durfee Wayne K. , Sheahan Mary
Published: December 2017

The effects of intramuscular injections of reserpine (Serpasil) on blood pressure, heart rate, body temperature and general behavior were determined on adult white leghorn capons 4 hours, and up to 24 hours after injection. The dosages used ranged from 0.006 to 0.75 mg/kg. Dosages from 0.006 upwards caused a significant drop in blood pressure, but the extent of drop was not appreciable at the lower doses. Doses from 0.01 to 0.75 significantly depressed heart rate, and the effects were greater and more consistent than for blood pressure. The changes in blood pressure and heart rate with log-dose were linear, but the heart rate response exhibited a closer fit to linearity. Moreover, the results suggest that heart rate response is an efficient assay method for reserpine-containing compounds. Dosages up to 0.10 mg/kg had no effect on body temperature but above this level body temperatures were depressed significantly. The tranquilizing dose for capons is between 0.10 and 0.2 mg/kg.