bluuebunny/crossref_metadata_2025 huggingface dataset:
Effect of Acetylphenylhydrazine on Myoglobin Concentration
Authors: Faulkner Willard R. , Blood Frank R.
Published: December 2017

Myoglobin concentration was determined on rats given acetylphenylhydrazine by subcutaneous injection. After 94 days the concentration of myoglobin in the muscles of these animals was determined and compared with that in control animals. Acetylphenylhydrazine caused a marked reduction in the myoglobin concentration; the mean for the treated animals was 0.87 ± 0.03 mg/gm of muscle and 1.31 ± 0.06 mg/gm for the controls. There was about an eightfold increase in the size of the spleens of the treated animals over the controls.
Effect of Unilateral Nephrectomy on Determination of Inulin Space in Dogs
Authors: Wisenbaugh Paul E. , Morningstar William A. , Feil George , Shumway Norman P.
Published: December 2017

When the inulin space in dogs is measured using the 5-hour urine recovery method before and after unilateral nephrectomy there is an apparent decrease postoperatively. The prenephrectomy ‘urine recovery’ inulin space and the postnephrectomy space determined by the ‘difference’ method are virtually the same. The apparent reduction may be partly due to the reduction in renal dead space but is chiefly due to the effect of the postnephrectomy reduction in inulin clearance on the completeness of recovery of inulin in the postinfusion urine collection.
Effects of Carbon Dioxide in the Rhinencephalon in the Marsupial Phalanger
Authors: Dunlop Colin W.
Published: December 2017

The effects of CO2 on the propagation of seizure discharges in the hippocampus in the marsupial phalanger have been examined. In addition, the effects produced by CO2 in the fornix-hippocampal system have been compared with simultaneous changes in conduction occurring in a thalamocortical system. Ten per cent and thirty per cent concentrations of CO2 raise the threshold for seizure discharges in the hippocampus, and have a greater effect on the fornix-hippocampal system than the thalamocortical system.
Effects of Surgery and Autologous Tissue Implantation on Liver Catalase Activity of the Mouse
Authors: Heim Werner G.
Published: December 2017

A sham operation equivalent to a unilateral nephrectomy and adrenalectomy, but without the removal of tissue, causes a considerable reduction in the liver catalase activity of mice. This effect is large enough to obscure the reduction in activity, if any, due to the implantation of coarsely minced autologous kidney and adrenal.
Effects of Adrenocortical Steroids on Carbohydrate Metabolism in Hypophysectomized Dogs; Studies With C14-Labeled Glucose
Authors: Altszuler N. , Steele R. , Wall J. S. , de Bodo R. C.
Published: December 2017

Hypophysectomized dogs exhibit severe disturbances in carbohydrate metabolism and in recent studies using C14 glucose it was shown that such dogs have a) smaller than normal body glucose pools and b) lower rates of glucose inflow into the plasma from the liver and glucose uptake from the plasma by the tissues. These dogs also have lower rates of total CO2 production. Since cortisone or hydrocortisone treatment ameliorates various abnormalities of carbohydrate metabolism in hypophysectomized animals, the effect of a steroid regimen (0.8–1.5 mg/kg/day for 8–16 days) on several parameters was studied in hypophysectomized dogs. Using the C14 glucose-dilution technique it was found that the steroid treatment resulted in a) an increment in body glucose pool size proportional to the simultaneously observed increase in plasma glucose concentration and, b) an increase in the rate of glucose output by the liver and glucose uptake by the tissues. The rate of total CO2 production was not altered by the steroid treatment. The untreated hypophysectomized dog, in contrast to the normal one, is unable to increase adequately glucose output by the liver in response to hypoglycemia resulting from an insulin-induced increase in plasma glucose uptake by the tissues. It is reasoned that the steroid treatment brings about an increased turnover of plasma glucose by a primary increase in the release of glucose by the liver, rather than by a primary increase in glucose uptake by the tissues. An increase in endogenous insulin secretion, brought about by the increased glucose release, could explain the increased glucose uptake by the tissues.
Osmotic Diuresis in the Unanesthetized Hydropenic Rat
Authors: Koike Thomas I. , Kellogg Ralph H.
Published: December 2017

The osmotic pressure of the plasma and urine of hydropenic female rats was determined by the freezing point technique during solute loading. The urinary osmolarity decreased asymptotically toward the plasma level when the rate of total solute excretion was increased by infusion of mannitol with or without vasopressin. The data can be quantitatively accounted for by assuming that urinary hypertonicity is achieved by reabsorption of solute-free water, up to a maximal rate of about 37 µl/min/100 cm2, from isotonic fluid present in the tubules distal to the sites of tubular solute transfer. Thus the rat resembles man and the dog in this respect. Similar results were obtained when the loading solute was NaCl, Na2SO4, PAH, creatinine or sucrose. Results during urea loading, however, constitute an exception to the general rule.
Mechanisms Regulating the Renal Transport of p-Aminohippurate
Authors: White Abraham G.
Published: December 2017

The uptake of PAH was studied by the method of Cross and Taggart. Secretion was studied in two ways: a) measuring the movement of PAH into the ambient medium from renal slices which had been preloaded with PAH by the intraperitoneal injection of this compound into rats 40 minutes before killing, and b) measuring the uptake of PAH by guinea-pig renal slices, its rate of acetylation, and the movement of the newly-formed paraacetylaminohippurate (PAAH) from the tissue cells into the medium. The velocity of secretion is approximately 5–7 times that of uptake. Uptake is inhibited by 2,4-dinitrophenol, cyanide and Pentothal, while secretion is not. Pentothal also blocks the stimulatory effect of acetate on the uptake of PAH. The interpretation of the effects of Pentothal, with regard to the mechanism of the stimulatory effect of acetate on uptake, is discussed.
Effect of Diamox (Acetazoleamide) on the Carbon Dioxide Tension of the Urine
Authors: Capeci Nicholas E. , Kruesi Oscar R. , Weaver Davis C. , Hilton James G.
Published: December 2017

In the anesthetized dog the pCO2 of the urine, arterial blood, and renal venous blood was measured before and after the intravenous administration of Diamox (acetazoleamide). The pCO2 of the urine always rose to a much greater degree than did the pCO2 of the arterial or renal venous blood This rise in urinary pCO2 could be explained satisfactorily neither by a rise in intracellular pCO2 nor by an increase in the rate of urine flow, but seemed best explained by the fact that Diamox itself acted as a urinary buffer.
Oxidative and Phosphorylative Metabolism of Rat Liver Tissue Following in Situ Anoxia
Authors: Hannon John P. , Cook S. F. , Leon Henry A.
Published: December 2017

Rat liver tissue subjected to varying periods of in situ anoxia was investigated in the Warburg apparatus using slices, homogenates and mitochondrial suspensions. Alterations occurring in the respiration of slices were determined by the use of lactate, acetate, citrate and glutamates as well as glucose. Using citrate as a substrate, it was found that homogenate media which contained ATP, when used for slices, prevented the decline in qO2 caused by anoxia. Mitochondrial recovery by the method used here showed a decrease as the anoxia interval progressed. This was found to be caused by a morphologic change attributable to the lack of oxygen. Mitochondrial oxidation and phosphorylation were studied and it was found that in those mitochondria recovered, the ability to produce high-energy phosphate bonds is significantly depressed by anoxia, reaching negligible values within 90 minutes.
Fructose Metabolism in Dairy Cows
Authors: Luick Jack R. , Kleiber Max , Lucas J. M. , Rogers T. A.
Published: December 2017

Metabolism of C14 fructose has been studied in dairy cows and the results compared to those obtained earlier with C14 glucose. C14 fructose disappeared rapidly from the plasma; simultaneously there occurred an immediate rise in plasma glucose C14. The pattern of isotope distribution in milk C and the peak expired CO2 specific activity was the same after fructose as after glucose injection. These results suggest that glucose is a key intermediate in the metabolism of fructose—the conversion of fructose to glucose presumably occurring in the liver. That fructose is also metabolized to a considerable extent by other pathways was indicated by the earlier peak—and more rapid decline—in expired CO2 specific activity. Further, considerably less fructose C14 was found in expired CO2 and in milk C 24 hours after injection. The extent to which fructose was metabolized by pathways which did not involve plasma glucose was estimated by comparing the integrated specific activity/time curves after fructose and glucose injection. It appears that up to 50% of the transfer of fructose C to expired CO2 and to milk C goes by pathways exclusive of blood glucose.
Effect of Intravenous Thiopental on Spontaneous and Evoked Eye Movements in Cats
Authors: Eliasson Sven G. , Hyde Jane E. , Bach-Y-Rita Paul
Published: December 2017

The effect of small intravenous injections of thiopental has been studied on spontaneous and evoked eye movements in the encéphale isolé cat. Spontaneous movements of the eyes decrease and tend to become dissociated for some minutes after thiopental. Electromyographic recordings from the extraocular muscles reveal a sharp reduction in spontaneous discharge during and after the injection, followed by a gradual recovery. Stimulation of brainstem sites which yielded conjugate deviations before thiopental frequently results in mid-positioning of the eyes after the injection, usually after a period of complete unresponsiveness. Recovery of the original evoked conjugate deviation may occur within 6 minutes upon stimulation of a site in the tegmentum of the medulla; it takes 20 minutes or longer for sites located in the midbrain tegmentum. Cortically evoked conjugate eye movements disappear for longer periods of time following thiopental injection. Some of the possible mechanisms of thiopental action are discussed with particular reference to the mid-positioning response so readily obtained on stimulation in an animal lightly anesthetized with a barbiturate.
Functional Analysis of the Cardioaugmentor and Cardioaccelerator Pathways in the Dog
Authors: Randall Walter C. , McNally Howard , Cowan Jerry , Caliguiri Lawrence , Rohse Wayne G.
Published: December 2017

The direct, electrical stimulation of the thoracic anterior roots, the communicating rami, and the upper thoracic sympathetic trunk in the dog reveals the preganglionic pathways followed by the cardiac accelerator and augmentor nerves. These nerve fibers are generally intermingled in each of the above pathways, but accelerator fibers are much more prominent on the right whereas augmentor fibers predominate on the left. The most significant pathways are via the T2 and T3 anterior roots and communicating rami, but significant responses were elicited from the T4 nerves and occasionally from the T1 and T5 nerves. Neither accelerator nor augmentor responses could be induced by stimulation of the C8 nerve nor by excitation of nerves below T5. It is concluded that preganglionic cardiomotor fibers enter the trunk between T1 and T5, course cephalad to the stellate ganglion where they may synapse or pass to the caudal cervical ganglion by way of the ansa subclavia. The stellate cardiac nerve furnishes a very important postganglionic augmentor and accelerator pathway, when it is present, but direct branches from the caudal cervical ganglia carry a majority of these fibers in most animals. Augmentor and accelerator fibers can not be functionally separated at any point in their anatomical pathways from the spinal cord to the heart. Responses seem to be determined rather, by the site of nerve terminations in heart tissue.
Absorption of Radioiron Perfused Through the Duodenum of the Rat
Authors: Hyde Alvin S.
Published: December 2017

Retention and postabsorptive distribution of iron were studied by perfusing the small intestine of the rat at a constant rate with radioiron-ascorbate in a medium of known and constant composition in the absence of bile and pancreatic secretions. The intestine accumulated radioiron as long as perfusion was maintained (125 min.). The amount of iron retained varied considerably, from 3.79 to 9.35 µg, but the percentage distribution of the retained iron followed a consistent pattern during 18 hours following perfusion. The amount retained was related to both length of time that the intestine was exposed to perfused iron and weight of the intestinal segment. Increasing the amount of iron-binding globulin in blood to three times the normal levels by intravenous injection of iron-free siderophilin decreased the amount of iron accumulating in intestine and increased the rate at which iron entered blood. The total amount of retained iron increased to 1.5 times the mean retention of control animals. The increased retention was accounted for primarily by the enlarged iron-carrying capacity of the blood.
Blood Flow in the Isolated Perfused Bovine Udder
Authors: Tindal J. S.
Published: December 2017

Rates of blood flow expressed per unit weight of tissue have been determined in the isolated perfused cow udder. An improved apparatus was used, enclosed in a Perspex cabinet, to enable the air surrounding the udder to be kept warm and moist, and also making the apparatus safe for work with C14-labeled compounds. All manipulations are carried out by remote control. In 6 out of 24 experiments, the rate of blood flow exceeded 20 ml/100 gm tissue/min., and the highest value observed was 26.4 ml/100 gm/min.
Influence of Perfusate Characteristics on Pulmonary Vascular Response to Endotoxin
Authors: Hinshaw Lerner B. , Kuida Hiroshi , Gilbert Robert P. , Visscher Maurice B.
Published: December 2017

The isolated ventilated dog lung was perfused with heparinized gelatin, dextran and plasma. The typical response to endotoxin of the isolated lung perfused with heparinized whole blood does not occur when gelatin or dextran are substituted as the perfusate. When plasma free from formed elements is used, the pulmonary vascular response to endotoxin is either minimal or does not occur. Lungs perfused with dextran, gelatin and plasma were shown to be reactive by their characteristic response to test drugs and by their subsequent response to endotoxin during perfusion with heparinized fresh whole blood. It is believed that endotoxin does not have a direct effect on lung tissue but that some components of whole blood are required for the pulmonary vascular response. These studies have not, however, excluded tissue factors nor have they conclusively shown whether plasma, formed elements or both, are involved in the pulmonary vascular response to endotoxin.
Effect of Estrogen on Iodinated Amino Acids of the Thyroid and Serum
Authors: Feldman Joseph D.
Published: December 2017

A chromatographic analysis of hydrolyzed and nonhydrolyzed thyroid tissue and of serum was made 6 and 24 hours after the administration of I131 to estrogen-treated and control castrate male rats. No consistent significant differences were noted between the thyroids and sera of experimental and control animals. Triiodothyronine was released more rapidly from the thyroids of all animals than was thyroxine. Thyroidal accumulation and renal excretion of I131 was also studied. When 10,000 iu of estrogen (1.0 mg estrone) were administered over 4 days, 24-hour renal excretion of I131 was significantly depressed. When 1000 iu of estrogen (0.1 mg estrone) were administered over 4 days, 24 hour renal excretion of I131 was depressed to a lesser degree. It was concluded that the action of estrogen on thyroidal uptake was twofold; indirect, by suppression of I131 urinary excretion and, most likely direct, from the evidence cited, by enhancing the iodide trapping mechanism.
Action of Insulin on Release of Fatty Acids From Tissue Stores
Authors: Bierman Edwin L. , Schwartz Irving L. , Dole Vincent P.
Published: December 2017

The mechanism by which carbohydrate utilization reduces the concentration of nonesterified fatty acids (NEFA) in plasma was studied by comparing the clearance of C14-labeled palmitic acid before and after the administration of insulin. The rate of disappearance from blood of a single injection of C14-labeled palmitic acid was identical before and after an intravenous injection of insulin (0.1 µ/kg) although the expected significant fall in total NEFA concentration occurred. When steady concentration of labeled NEFA was maintained by a constant infusion, the administration of insulin produced a significant increase in specific activity. It is, therefore, concluded that insulin decreases the release of fatty acids from tissue stores but does not accelerated their removal from blood.
Evaluation of the Cell Separation Hypothesis of Autoregulation of Renal Blood Flow and Filtration Rate
Authors: Thompson D. D. , Kavaler F. , Lozano R. , Pitts R. F.
Published: December 2017

Renal blood flow (RBF) and glomerular filtration rate (GFR) were measured in anesthetized normal and anemic dogs at normal and reduced renal arterial pressures. Reductions in pressure were produced by inflation of a balloon catheter positioned fluoroscopically above the origins of the renal arteries. Sampling of renal venous blood via a catheter inserted under fluoroscopic visualization allowed a calculation of renal blood flow by the Fick equation, utilizing PAH excretion and blood values. Control values of GFR and RBF progressively declined during the course of most experiments. After correction of data to constant control values, it was found that autoregulation of GFR and RBF was present in both normal and anemic animals to approximately the same degree. These findings are in contrast to the reports of Pappenheimer and Kinter, who found a reduction or loss of autoregulation in acutely anemic cats, and in a few anemic dogs. In accord with the findings of Pappenheimer and Kinter, we found a reduction in PAH extraction in the anemic animals. However, we failed to find a correlation between PAH extraction and arterial pressure, which argues against their thesis of cell separation as a cause of autoregulation. In a separate series of experiments it was found that plasma volume expansion by dextran or plasma was usually associated with a reduction in PAH extraction but that there was no apparent correlation between the extent of the expansion of plasma volume and the extent of the reduction in PAH extraction.
Interaction Between Thyroxine and Dibenzyline on Metabolic Rate
Authors: Schwartz Neena B. , Hammond Gerald E. , Gronert Gerald A.
Published: December 2017

Doses of Dibenzyline adequate to block the pressor effect of epinephrine were administered to rats with various degrees of chronic hypo- or hyperthyroidism. Rate of oxygen consumption was measured under barbiturate anesthesia. Dibenzyline decreased or did not change hypothyroid metabolic rates, but increased metabolic rates in hyperthyroid rats. The data indicated that Dibenzyline exerts a synergistic effect with thyroxine on metabolism resembling the previously reported synergism between thyroxine and epinephrine. Apparently discrepant findings presented in the literature regarding the interaction of thyroxine and Dibenzyline probably result from differences in the thyroid status of the experimental animals.
Effect of Varying the Hematocrit Ratio on the Susceptibility to Hemorrhagic Shock
Authors: Crowell Jack W. , Bounds Sara H. , Johnson W. W.
Published: December 2017

By the use of a) acetyl phenylhydrazine, b) hemorrhage, c) transfusion, and d) natural variation, 67 dogs with hematocrit ratios varying from 12 to 56 were obtained. These dogs were subjected to hemorrhagic shock by lowering their arterial blood pressure to 30 mm Hg, and the time lapse between the initial production of hypotension and the beginning deterioration of the animal determined. This time lapse is a measure of the resistance of the animal to the development of irreversible shock. A graph of initial hematocrit versus the time required for the development of irreversible shock shows that an increase in the hematocrit ratio from 12 to 35 increases the resistance of the animals by a factor of approximately 5; however, increasing the hematocrit ratio above 35 decreases the resistance of the animal to the development of irreversible shock.
Distribution of Urokinase Among the Common Mammals
Authors: Mohler Stanley R. , Celander D. Robert , Guest M. Mason
Published: December 2017

Urokinase, a principle capable of activating profibrinolysin to fibrinolysin, has been found in the urine of the cat, rat, cow, rabbit, man, dog and hamster. Soluble concentrates of this activator were prepared by precipitation of urine with equal volumes of cold acetone, suspension of the precipitate in borate buffer and sequential dialysis of the suspension against borate buffer (ph 9.2), distilled water and phosphate buffer (ph 7.25). The ability of the urokinase concentrates from the urine of a given species to activate the profibrinolysin of its own and various other species was measured in a two-stage assay system which is described. The activation of profibrinolysin by urokinase was limited by definite species specificities and did not appear to involve the intermediation of a plasma prokinase.
Uretero-Renal Reflex Facilitating Renal Vasoconstrictor Responses to Emotional Stress
Authors: Hix Elliott Lee
Published: December 2017

In trained and conscious dogs, with ureters exteriorized in flank skin-flaps to facilitate the simultaneous determination of unilateral renal function, it was determined that unilateral irritation of the ureter reflexly produced a decrease in renal plasma flow and glomerular filtration rate in the ipsilateral kidney. Three unilateral renal response patterns were observed on catheterizing the ureter. This uretero-renal reflex was always unilateral and ipsilateral with respect to the stimulated ureter, and could be blocked by anesthetizing the ureter, denervating and/or transplanting the kidney. It was determined that sensory fibers from the ureter communicate reflexly with renal efferent vasoconstrictor fibers. These ureteral afferent fibers pass up the entire length of the ureter where they probably enter the splanchnic nerves. Afferent discharges from the stimulated ureter, whether acute or subliminal, selectively promoting the recruitment of preganglionic neurons, effectively facilitate renal nerve pathways to the kidney under conditions of sympathetic activation (stress). It was concluded that the mechanism of action of this uretero-renal (viscero-visceral) reflex, and its functional significance to renal vasomotor regulation, is that of a facilitating phenomenon. By this facilitating action it channelizes sympathetic activity into efferent renal nerve pathways, exposing the kidney to an exaggerated impact from general and nonspecific environmental stress factors.
Determination of the Total Carbon Dioxide Outputs of Rats By the D2O18 Method
Authors: McClintock Ruth , Lifson Nathan
Published: December 2017

The doubly-labeled water (D2O18) method for measuring CO2 output has been tested in eight rats by comparing the value obtained by this procedure with the total CO2 actually collected. The average absolute discrepancy between the two values was 3 (±3)%, and the average discrepancy when account was taken of algebraic sign was +2 (±4)%. (The values in parentheses are standard deviations of the distributions.)
Blood Ammonia Elevation and Toxicity From Intravenous L-Amino Acid Administration to Dogs: the Protective Role of L-Arginine
Authors: Fahey John L. , Perry Robert S. , McCoy Patricia F.
Published: December 2017

A nontoxic intravenous l-amino acid mixture became markedly toxic when l-arginine and l-histidine were deleted from the mixture and was capable of producing convulsions and death in dogs. Associated with these infusions was a marked increase in blood ammonia levels that coincided with the signs of toxicity. Similar toxicity was produced by infusion of ammonium salts. Administration of l-arginine·HCl prior to or with the infused amino acid mixture prevented the toxicity and the blood ammonia rise. Subsequent injection of l-arginine·HCl produced a prompt fall in blood ammonia to normal levels. l-Ornithine·HCl or l-citrulline·HCl were similarly effective. d-Arginine·HCl and l-histidine·HCl were ineffectual. Urea production was more rapid when l-arginine was added to the infused amino acid mixture. The results suggest that the Krebs-Henseleit cycle is a functioning metabolic pathway that normally is a major deterrent to the accumulation of excessive blood ammonia when large amounts of amino acids are infused.
Effect of Gram-Negative Endotoxin on Pulmonary Circulation
Authors: Kuida Hiroshi , Hinshaw Lerner B. , Gilbert Robert P. , Visscher Maurice B.
Published: December 2017

Effects of endotoxin on the pulmonary hemodynamics of dogs and cats have been studied in intact animals, open chest animals with and without control of cardiac output by an extracorporeal venous reservoir—pump system, and in isolated perfused continuously weighed lungs. Pulmonary artery pressure increased without a rise in left atrial pressure in all preparations following the injection of endotoxin. Pulmonary artery wedge and small pulmonary vein pressures uniformly increased. Total pulmonary vascular, pulmonary arterial and pulmonary venous resistances were calculated in five perfused lungs. The absolute increase in pulmonary venous resistance was greater than in the arterial resistance in four of the five studies and was relatively greater in every instance. There was a consistent increase in lung weight associated with these hemodynamic changes. Analysis of the determinants of lung weight changes has provided evidence to support the conclusion that the pulmonary vascular response to endotoxin administration is characterized predominantly by constriction of pulmonary venules and/or small veins.
Effect of Pentobarbital Anesthesia on Tmpah in the Dog
Authors: Støren E. J.
Published: December 2017

Tmpah was determined with and without pentobarbital anesthesia in six mongrel female dogs with both kidneys explanted to a subcutaneous position. A consistent 26.5% depression of Tmpah was seen in the anesthetized animals, as judged by the combined means of 12 experiments with anesthesia and 12 experiments without anesthesia. The depression was manifested as early as 1 1/2 hours after induction of anesthesia, and was constant for at least 1 hour. Anesthesia caused no change in glomerular filtration rate, effective renal plasma flow, or filtration fraction.
Emetic Action of Nitrogen Mustard (Mechlorethamine Hydrochloride) in Dogs and Cats
Authors: Borison H. L. , Brand E. D. , Orkand R. K.
Published: December 2017

The early emetic response (within 4 hr.) after intravenous injection of the nitrogen mustard, methyl-bis (beta-chlorethyl) amine hydrochloride, was compared in dogs and cats. The emetic effect of the drug in dogs differed from that in cats in the following respects: a) the dose of 0.5 mg/kg was uniformly effective in dogs whereas the lowest uniformly effective dose in cats was 5.0 mg/kg. b) Dogs were completely protected against the emetic effect, up to 10.0 mg/kg, by chronic ablation of the medullary emetic chemoreceptor trigger zone (CT zone), whereas cats were not. Cats were completely protected against the emetic effect by abdominal deafferentation accomplished by transthoracic vagotomy in combination with either spinal cord transection at T4 or dorsal rhizotomy of spinal segments T5 to T10. The dose-response curve for emesis after nitrogen mustard in the cat was shifted towards a higher dose level by acute decerebration. A forebrain facilitatory role was further supported by a protective effect, against the mustard-induced vomiting, afforded by chronic frontal lobectomy in the cat. Attention is directed to the similarity in emetic actions of nitrogen mustard and x-radiation, including parallel species differences between dogs and cats.
Reversible Heat Block of Electrical Activity in the Goldfish Brain
Authors: Cerf Jean A. , Otis Leon S. , Takagi Sadayuki F.
Published: December 2017

The effect of temperature elevation on the electrical activity of the vagal lobe was studied in both intact and isolated goldfish brain. The slow potential changes recorded at room temperature ceased above a critical temperature (about 37°C), and reappeared on cooling. The degree of reversibility of the block was inversely proportional to the duration of heat application and the final temperature of the brain immediately preceding cooling.
Factors Determining the Liver Glycogenating Action of Orinase
Authors: Henry W. L. , Kim John H. , Hall Alice S.
Published: December 2017

The liver glycogenating action of Orinase was studied in normal, adrenalectomized and alloxan diabetic rats. The adrenalectomized rats were studied in three groups, salt maintained, cortisone maintained and cortisone plus adrenaline maintained. The alloxan diabetic rats were studied in two groups, protamine zinc insulin (P.Z.I.) maintained and uncontrolled. Of the adrenalectomized rats only those maintained on cortisone plus adrenaline responded to Orinase administration with increased liver glycogen. The alloxan diabetic animal maintained on P.Z.I. presented increased liver glycogen after Orinase administration but the untreated alloxan diabetic rat did not. This series of experiments indicated that the liver glycogenating effect seen during Orinase administration requires the participation of adrenomedullary, adrenocortical and beta cell hormones.
Influence of Diet on Glucose Tolerance
Authors: Uram J. A. , Friedman L. , Kline O. L.
Published: December 2017

Observations are reported in which the curves obtained from the glucose tolerance test depend upon the nature of the diet on which the animals have been maintained. On a casein sucrose diet the glucose blood levels approach 200 mg % as compared to 120 mg % on a cereal ration. These observations are discussed in the light of the work of von Noorden and Himsworth. It is suggested that they may be explained either by the metabolic adjustment to the digestion of complex carbohydrates or to the presence of a hypoglycemic substance.
Sensitivity of Paramecium Caudatum to High Oxygen Tensions and Its Modification by Cobalt and Manganese Ions
Authors: Gerschman Rebeca , Gilbert Daniel L. , Frost Justin N.
Published: December 2017

Paramecia were put in a hanging drop in a special chamber in which they could be observed under the microscope while they were exposed to different pressures of oxygen. Characteristic morphological changes were recorded photographically and were found to be very similar to changes induced by radiation. Survival times decreased from 8.05 hours at 2 atm. to 0.87 hours at 20 atm. of pO2. Treatment with cobalt (II) chloride and manganese (II) chloride (m/200,000) increased the survival times at 9 atm. and decreased them at 2 atm. pO2.
Capillary Resistance and the Corticoids
Authors: Kramár Jenö , Levine Victor E. , Meyers V. William , Sass Robert N.
Published: December 2017

In an attempt to elucidate further the relationship of capillary resistance to the adrenal corticosteroids, capillary resistance was studied in connection with the plasma concentration and excretion of the 17, 21-dihydroxycorticosteroids in three groups of experiments. The actual concentration of these steroids in the plasma of nonstressed subjects failed to show any correlation with the actual capillary resistance level. The stress-induced increase in capillary resistance (capillary stress response) was accompanied by simultaneous changes in the plasma concentration or excretion of these corticosteroids in some experiments. In other experiments, on the other hand, plasma concentration and elimination of the corticosteroids did not change despite marked capillary response. This failure to demonstrate a consistent correlation between capillary resistance and plasma concentration and urinary excretion of the 17, 21-dihydroxycorticosteroids militates against a direct relationship of capillary resistance to adrenocortical activity and suggests the existence of another factor as playing a role in the capillary resistance-corticosteroid relationship.
Autonomic Balance in Cardiac Control
Authors: Rushmer Robert F.
Published: December 2017

Stimulation of the sympathetic nerves to the heart in anesthetized dogs produced tachycardia and changes in left ventricular performance, including alterations in both pressures and dimensions. Stimulation of the vagus nerves in dogs predominately induced a bradycardia. When the heart rate was controlled by an artificial pacemaker, sympathetic stimulation produced changes in ventricular performance. By adjustments in stimulus frequency, the effects of vagal and sympathetic stimulation on heart rate could be balanced, but complete cancellation of effects was impossible because the vagus had a more powerful effect on heart rate and the sympathetic nerves had a greater influence on mechanical performance.
Excretion of Phenol Red and Inulin by the Fetal and the Newborn Rabbit
Authors: Levine Joseph , Levine Ann D.
Published: December 2017

Simultaneous clearances of phenol red (PSP) and inulin (in) were measured in fetal, newborn and adult rabbits. The clearances were determined from single injection and single blood and urine collections. This method tends to reduce the numerical values of the clearances but not to change the ratios of the two clearances when compared with clearances obtained by conventional methods in adult rabbits. The CPSP/Cin ratio fell from a fetal value of 0.4 to a newborn level of 0.2 and then rose to approximate the adult ratio of 2.0 by 1 month after birth. The use of plasma PSP concentrations both above and below the adult TmPSP did not influence significantly the clearance ratios in young animals. The percentage of total PSP not bound to plasma proteins, determined by ultrafiltration, was more in the newborn plasma (30%) than in adult plasma (4%). Both are greater than might be predicted from an adsorption isotherm using constants determined in adult blood by others. It was concluded that the rise in clearance ratio with age probably reflected both an increase in filtration with age and a greater increase in tubular secretion with age; and that these factors were more important than corresponding changes in the binding of PSP by plasma proteins in young and adult animals.
Effect of Phenylhydrazine and Bone Marrow Inhibitors on Red Cell Destruction and Serum Iron Concentration
Authors: Chanutin Alfred
Published: December 2017

The administration of sublethal doses of bone marrow depressants (nitrogen mustard, triethylene melamine and thioguanine) causes a temporary, moderate increase in serum iron concentration, a slight depression of bone marrow activity and no change in hemoglobin concentration. A combination of any of these drugs with a small dose of phenylhydrazine causes a temporary marked hyperferremia, a moderate anemia and a marked reticulocytosis. The results indicate that hyperferremia is not necessarily associated with bone marrow activity.
Cardiovascular Responses to Pressure Alterations Within the Urinary Tract of the Dog
Authors: Berman Leonard B. , Rose John C.
Published: December 2017

Acute changes in pressure within the bladders and renal pelves of intact, anesthetized dogs were produced by the infusion of normal saline. Direct and continuous observations were made of aortic, right ventricular and intravesical or intrapelvic pressures, as well as the electrocardiogram. No significant cardiovascular alterations were observed during acute and extreme increments and decrements of intraluminal urinary tract pressures. These results are in marked contrast with those seen in reptilia and amphibia.
Carbohydrate, Electrolyte and Amino Acid Metabolism in the Anoxic Newborn Lamb
Authors: Brandt Ira K. , Harned Herbert S. , Cooke Robert E.
Published: December 2017

Newborn lambs are delivered by hysterotomy, their respiratory passages occluded, and their umbilical cords ligated. Periodic aortic blood samples taken before and for 15 minutes after ligation demonstrate the accumulation of lactate and potassium in the plasma, an elevation of PCO2, a fall in the pyruvate concentration, and no significant change in the glucose, sodium, chloride, phosphate or free amino acid concentrations.
Adaptation to Forced Exercise in the Rat
Authors: Thomas Barbara M. , Miller A. T.
Published: December 2017

The influence of forced exercise (treadmill running) on food intake, body weight and spontaneous activity was studied in male albino rats. The initial response to gradually increasing exercise load was a decrease in food intake and body weight on exercise days, with compensatory increase in both factors on rest days (week-ends). By the time exercise had been increased to 1 mile/day, food intake on exercise days had returned to normal or slightly above, and food intake on rest days was significantly elevated. During the recovery period following the exercise experiment, food intake remained elevated despite the absence of a significant weight deficit. Overnight spontaneous activity was strikingly reduced in exercised rats, with only partial restoration on rest days, and with gradual return to normal during the postexercise recovery period.
Renal Excretion of l-Epinephrine in the Dog
Authors: Jones Richard T. , Blake William D.
Published: December 2017

The renal excretion of epinephrine was studied in dogs anesthetized with sodium pentobarbital. Epinephrine in plasma and urine was quantitatively estimated by the fluorometric method of Lund. Glomerular filtration rate (creatinine clearance), renal plasma flow (PAH clearance) and PAH transport were employed as parameters of renal function. During periods of intravenous infusion of epinephrine, the percentage of hormone excreted was about 4.6% of that infused. The renal clearance of epinephrine was significantly greater than the glomerular filtration rate though less than renal plasma flow. From this and other information it was concluded that epinephrine is excreted both by tubular transport (tubular secretion) and glomerular filtration. The tubular transport of epinephrine was not inhibited by either 2,4-dinitrophenol or an adrenergic blocking agent.
Influence of Rhythmic and Tonic Contraction of Intestinal Muscle on Blood Flow and Blood Reservoir Capacity in Dog Intestine
Authors: Sidky Mahmoud , Bean John W.
Published: December 2017

The influence of rhythmic and tonic contractions of intestinal muscle on intestinal blood flow and reservoir capacity were studied in isolated, perfused segments of dog intestine set up in a constant temperature plethysmographic chamber, or isolated in situ with extrinsic nerves intact. Blood flow recorded continuously by thermopile and drop methods showed that rhythmic intestinal contractions caused a reciprocal periodicity in arterial and venous flows due to a positive pumping action which can develop venous pressures well in excess of the arterial inflow and therefore contributes importantly to the active propulsion of blood through the intestine and the liver. Prolonged tonic contraction diminishes intestinal blood flow and may nullify the augmentative influence of the rhythmic contractions and/or of vascular dilatation. Decreased intestinal tonus by itself augments intestinal blood flow even in the absence of rhythmic contractions. Intestinal tonus is therefore an important determinant of the functional blood reservoir capacity of the intestine, the total peripheral resistance and the degree of intestinal hemostasis. These motor influences on intestinal blood flow are superimposed upon those of the intestinal vasculature per se, which thereby may be augmented, completely masked or even reversed. These data find ready explanation in a consideration of the peculiar anatomical features of the intestinal vasculature.
Metabolism of Choline by Slices of Fatty Livers From Choline-Deficient Rats
Authors: Rees E. Douglas , Kline Daniel L.
Published: December 2017

Fatty livers were produced in rats by a choline-deficient diet and the metabolism of slices from the livers was studied. The addition of choline increased the qo2 of slices of fatty liver more than it did the qo2 of control slices. The qco2 and R.Q. of both types of slices decreased in the presence of choline. For both the control and the fatty liver slices, an increased concentration of an unidentified material, (probably not betaine aldehyde), which reacted with 2,4-dinitrophenylhydrazine was found whenever the respiration medium contained choline. Fatty liver slices produced more of this substance relative to oxygen uptake.
Hypercholesteremic Effect of Various Phospholipid Preparations
Authors: Byers Sanford O. , Friedman Meyer
Published: December 2017

Twelve phosphatide preparations from vegetable, animal, yeast and synthetic sources were infused intravenously into normal or functionally hepatectomized rats at such a rate as to maintain plasma phospholipids at 2–10 times normal levels over a period of 6–24 hours. Consequent upon such infusion, plasma cholesterol concentration rose significantly. All preparations were active in greater or lesser degree, with the exception of duck egg lecithin.
Measurement of ‘Basal’ and Total Metabolism in Hereditarily Obese-Hyperglycemic Mice
Authors: McClintock Ruth , Lifson Nathan
Published: December 2017

Measurements of oxygen consumption and carbon dioxide production were made by the Haldane open circuit method on hereditarily obese mice and littermate controls, and the energy expenditures were estimated. Studies were made on mice for short periods under ‘basal’ conditions, and for periods of approximately a day with the mice fasted and confined, fasted and relatively unconfined, and fed and unconfined. The total energy expenditures of fed and unconfined obese mice were found to be higher than those of nonobese littermate controls by virtue of a) increased ‘basal metabolism’, b) greater energy expenditure associated with feeding, and possibly c) larger energy output for activity despite reduced voluntary movement. The values obtained for total metabolism confirm those previously determined by an isotope method for measuring CO2 output.
Heat Balance in Restraint (Emotionally) Induced Hypothermia
Authors: Bartlett R. G. , Quimby F. H.
Published: December 2017

Hypothermia produced by restraint in the rat was shown to be due to an increased rate of heat loss (rather than to a decreased heat production) as a result of: a) a greater effective body surface exposure in the restrained rat as compared to the nonrestrained control animal (effective body surface exposure is that portion of the surface radiating to objects other than opposing areas of the animal's own body surface). b) A greater rate of heat loss per unit of effective body surface exposure in the restrained rat as compared to the nonrestrained control.
Trophic Effects in the Absence of Respiratory Function of the Phrenic Nerve
Authors: Jefferson N. C. , Ogawa T. , Necheles H.
Published: December 2017

In the dog, section of a phrenic nerve is followed by progressive and finally complete atrophy of the muscle of the hemidiaphragm. If a phrenic nerve is crushed, or cut and reunited by primary anastomosis, no degeneration of the diaphragm is seen, although respiratory function is absent for about 3 months. Likewise, no atrophy of the diaphragm occurs after vagophrenic anastomosis. Therefore, trophic effects may exist in the absence of functional activity and they may be transmitted by another nerve, independent of its original function.
Changes in Renal Function During Induced Apnea of Diffusion Respiration
Authors: Bohr V. C. , Ralls R. J. , Westermeyer R. E.
Published: December 2017

If apnea is induced in dogs by overdoses of thiopental sodium, urine production will be greatly diminished or totally cease, despite good hydration, normotensive arterial pressures and adequate oxygenation of the animals by means of diffusion respiration. This oliguria or anuria can be largely reversed by infusion of osmotic diuretics, although mercurial-xanthene diuretics and Diamox diuretics do not alter the course of the developing anuria. Likewise, unilateral surgical stripping of the renal pedicle, unilateral splanchnicectomy, or spinal hemisection cause the kidneys on the side of the lesions to continue to produce urine after the contralateral intact kidneys become anuric. The clearances of PAH and creatinine are depressed in both intact and surgically denervated kidneys during the apnea. However, the depression is very much less in the denervated kidneys. A diminution in PAH extraction ratios, which appear to correlate with a drop in blood pH, was also observed.
Effects of Central Venous Congestion on Sodium, Potassium and Water Metabolism in the Rat; Response to Desoxycorticosterone
Authors: Yates F. Eugene
Published: December 2017

Passive venous congestion of the liver following constriction of the inferior vena cava above the hepatic veins impairs the renal excretion of sodium and water loads, and greatly increases the responsiveness of rats to the sodium-retaining and life-maintenance effects of desoxycorticosterone. These experiments support the hypothesis that the in vivo rate of inactivation of adrenal cortical hormones may be impaired by central passive venous congestion, and suggest the possibility that the secondary aldosteronism of congestive heart failure may be accounted for in part by a defect in steroid metabolism.
An Analysis of Human Prothrombin by Starch Block Electrophoresis
Authors: Lanchantin Gerard F.
Published: December 2017

Prothrombin preparations, obtained from human ACD blood plasma and characterized by certain chemical, physical and biological measurement, were subjected to various types of electrophoretic analysis. Evidence obtained by starch block electrophoresis of these products appears to indicate that human prothrombin requires a factor similar in properties to prothrombin itself, for optimum biological conversion to thrombin in vitro.
Eosinophil Cell Reaction in Male and Female Rats During Adaptation to High Altitude
Authors: Kostial Krista , Šimonović Ivan , Häusler Vera
Published: December 2017

Male and female albino rats were exposed to a simulated altitude of 31,600 feet for 30 minutes daily. According to the eosinophil cell reaction female rats became adapted to hypoxia more rapidly than male animals. Moreover, the acquired adaptation was retained much longer by females.
Effects of Hypothermia on Contractility of the Intact Dog Heart
Authors: Goldberg Leon I.
Published: December 2017

The effects of hypothermia on ventricular contractility were studied in intact dogs, directly, by attachment of a strain gauge arch to the myocardium and indirectly, by observation of left and right atrial, pulmonary and femoral arterial pressures. Marked increments in heart contractile force and reduction in the rates of contraction and relaxation occurred in all experiments during cooling. Myocardial depression occurred in several experiments, but only at temperatures near 20°C, and in the presence of extreme bradycardia. Total sympathetic block produced by epidural injections of 0.45% procaine solution and large doses of hexamethonium did not prevent development of the increments in heart contractile force, but did further decrease the rates of contraction and relaxation at low body temperatures. Epinephrine administration resulted in pronounced increments in heart contractile force and increases in rates of contraction and relaxation, often in the absence of chronotropic effects. No relationship was found between occurrence of ventricular arrhythmias and magnitude of heart contractile force. Spontaneous occurrence of fused contractions, with apparent summation and incomplete tetanus was observed in several experiments at low body temperatures.