bluuebunny/crossref_metadata_2025 huggingface dataset:
Influence of Dietary Amino Acids on Pancreatic Enzymes
Authors: Hong S. S. , Magee D. F.
Published: December 2017

Rats were fed a low casein diet to which was added either single dl-amino acids to make 1% of the diet or supplements of dl essential amino acids equivalent proportionally and in total amount to an extra 8% casein. Glycine was added to substitute for the nonessential acids in casein. In six groups of rats this supplement was lacking in pairs of essential amino acids previously found to stimulate protease and lipase production. The pairs were made up of all possible combinations of the four acids in question. Threonine addition reduced all enzyme activities. Threonine removal increased protease activity. Arginine and histidine additions increased protease and lipase respectively. The complete amino acid supplement reduced protease below the control as did the supplement lacking in methionine and phenylalanine. No activity was increased by any amino acid mixture supplement. Lipase and amylase were unchanged by the mixtures except for an amylase depression in the group receiving a supplement lacking isoleucine and valine.
Effects of Hormones on Carbohydrate Metabolism in the Alligator
Authors: Stevenson Octavia R. , Coulson Roland A. , Hernandez Thomas
Published: December 2017

The use of cold-blooded animals in research on carbohydrate metabolism permits one to observe the effects of stimuli for a period of days instead of minutes. With this fact in mind, epinephrine, insulin, hydrocortisone, glucagon and purified bovine somatotropin were injected into young alligators for various periods of time. Following the injections, bloods and urines were analyzed for glucose, lactate and electrolytes. Epinephrine and glucagon produced a 250–400 mg % rise in blood glucose. This hyperglycemia lasted for as long as 70 hours. Whereas epinephrine evoked a marked hyperlactemia which lasted for 10–20 hours, glucagon had no effect on lactic acid. Alligators primed with hydrocortisone showed a decreased ability to dispose of the lactic acid produced by epinephrine. Although epinephrine quickly reduced the stores of liver and muscle glycogen, the glycogen supply was replenished in 5 days or less, even when the alligators were deprived of food. Both somatotropin and hydrocortisone produced a slight hyperglycemia when given singly. When combined, they caused a marked hyperglycemia with glycosuria. In spite of the production of an apparent ‘diabetes,’ these alligators disposed of exogenous glucose at a nearly normal rate.
Effects of Cold on Evoked Cortical Potentials in the Rat
Authors: Battista Arthur F.
Published: December 2017

In the rat anesthetized with Nembutal, stimulation of the sciatic nerve elicited two cortical responses from the sensori-motor cortex. The characteristics of these effects were similar to the ‘primary response’ and the ‘secondary discharge’ recorded by others from the sensori-motor cortex of the cat when the sciatic nerve was stimulated. As the rat was cooled, the primary response increased in size, and the maximum amplitude of two to three times the normal value was found at the calculated brain temperature of 26° to 20°C. Although, no spontaneous electrical cortical activity was present at the calculated brain temperature of 18° to 16°C, the primary response always could be evoked down to a temperature of 15° to 13°C. On warming the animal, the primary response reappeared at 18° to 25°C.
Acute Effects of Acetazolamide (Diamox) on Plasma and Urinary Electrolytes of Dogs With Special Reference to Calcium
Authors: Freeman Smith , Jacobsen Anne B.
Published: December 2017

Administration of Diamox by ingestion or injection to adult fasting female dogs consistently produced an acute increase of approximately 1 mg % in the plasma concentration of calcium. At the same time there was an increase in the plasma phosphate and chloride concentration and a decrease in total plasma content of carbon dioxide of Diamox-infused dogs. Diamox did not affect the plasma concentration of calcium, chloride or bicarbonate if renal excretory function was abolished prior to its administration. Infusion of Diamox produced a prompt rise in the urinary excretion of sodium, potassium, calcium, phosphate, citrate, chloride and water in fasting female dogs. The effect of Diamox on the fasting concentration of calcium rendered unsatisfactory the interpretation of data concerned with a study of its effect on the disappearance of injected calcium. However, intravenous injection of small amounts of sodium carbonate was found to produce a definite delay in the rate of disappearance of injected calcium.
Mechanisms Causing Bilateral Pulmonary Edema Following Unilobar Miliary Embolization as Revealed by the Action of Certain Pharmacological Agents
Authors: Laurent Daniel , Larrain G. , Singer Donald , Pick Ruth , Katz Louis N.
Published: December 2017

The effect was studied of a number of drugs upon the severe bilateral pulmonary edema resulting from unilobar embolization of the lung, with 1 gm of starch. The edema in the embolized and nonembolized portions of the lung do not exhibit a uniform response to the several drugs tested. Intravenous Chlor-Trimeton, dibenamine, and Benodaine markedly inhibit its formation in the latter, but do not affect its appearance in the former. Procaine inhibits edema formation throughout the lungs. Its effect, however, is less marked in the injected than in the uninjected lobes. Atropine has an equivocal effect on the distant edema and no effect on that in the embolized lobe. The difference in response to drugs between the injected and the uninjected lung lobes suggests a possible difference in pathogenesis of the edema formation in these areas. The protective action of procaine on edema formation in the injected lobe suggests that a neural element may be involved acting on capillary permeability. In view of the ineffectiveness of antiadrenergic and antiparasympatholytic agents on the edema in this area, the possibility of axone-type reflex is suggested. However, the refractoriness of the local edema to the several drugs which exert a profound effect on the distant edema could also be due to an acute deterioration of capillary integrity accompanying the local trauma of massive embolization. The failure of Chlor-Trimeton to noticeably inhibit edema formation in the embolized lobe militates against histamine's importance in the genesis of the changes there. The marked inhibition of the edema formation in the nonembolized lung lends credence to the view that it is of the neurogenic or neuro-humoral variety.
Absorption of Various Fluorine Compounds From the Gastrointestinal Tract of the Rat
Authors: Zipkin I. , Likins R. C.
Published: December 2017

The absorption of variously bonded fluorine compounds from the gastrointestinal tract of the rat was determined. NaF, Na2SiF6, Na2PO3F and SnF2 were absorbed to the same extent (48%), whereas KPF6, EtNPF6 and KBF4 were absorbed to a significantly greater degree (74%). The results suggest that covalently held fluorine compounds are absorbed at a greater rate than the fluoride ion.
Dermal Lactic Acid Content and Development of the Local Shwartzman Reaction
Authors: Roethel Suzanne B. , Kelly Margaret G. , Rall David P.
Published: December 2017

Changes in metabolism and lactic acid content of prepared skin were studied in relation to intradermal dose level, polysaccharide preparation used, effect in tolerant rabbits and incidence of dermal Shwartzman reactions which could be provoked subsequently by a standard intravenous injection of a Shwartzman-active polysaccharide preparation from S. marcescens. Respiration of skin was not altered significantly by polysaccharide injection, although glycolysis was increased. The change in lactic acid content of skin varied directly with intradermal dose of bacterial polysaccharide. Doses adequate to produce significant increase in skin lactic acid also were adequate to prepare for subsequent development of the Shwartzman reaction in 80% of rabbits. Further increase in dose and skin lactic acid did not increase the incidence of positive reactions. Comparable incidence of Shwartzman reactions and increase in skin lactic acid were caused by intradermal injection of a plant polysaccharide (inactive as provocative material) but not by heat-inactivated bacterial polysaccharide. In tolerant rabbits, skin lactic acid was increased significantly by intradermal injection of bacterial polysaccharide but no Shwartzman reactions could be provoked subsequently.
Absorption of Atropine From Muscle
Authors: Schriftman Herbert , Kondritzer Albert A.
Published: December 2017

Rates of absorption of atropine after intramuscular injection have been studied by measuring colorimetrically the residual drug in guinea pig muscle. Effects of volume and concentration of the injected solution and the presence of hyaluronidase and polyvinylpyrrolidone on the absorption rates were investigated. Results indicate that, within the range of volumes and concentrations used, for a constant amount of atropine the smaller the volume of injected solution the faster the drug cleared the muscle; solutions of similar volume showed initially faster absorption when a lower concentration of drug was present. Addition of hyaluronidase produced an immediate increase in the clearance rate: four times as much atropine cleared the muscle in the first 35 seconds compared to an untreated solution. Addition of polyvinylpyrrolidone had no appreciable effect.
Metabolism of Insulin-I131 and Glucagon-I131 in the Kidney of the Rat
Authors: Narahara H. T. , Everett N. B. , Simmons B. S. , Williams R. H.
Published: December 2017

Crystalline insulin or glucagon labeled with I131 was injected intravenously in adult male Sprague-Dawley rats under ether anesthesia. The left kidney was removed at intervals ranging from 10 seconds to 6 minutes following the injection, and radioautographs of histological sections were prepared. Radioactivity was found to be concentrated in the cortex of the kidney. At intervals less than 2 minutes after injection, radioactivity was prominent in the lumina of proximal convoluted tubules. At later intervals radioactivity tended to become more concentrated in the cells of the proximal tubules than in the lumina. The observations support the hypothesis that proteins may be filtered through the glomerular membrane and reabsorbed in the tubules.
Development of a Skin Burn Technique Protection Afforded Rats by Prescald Subcutaneous Air Insufflation
Authors: Einheber Albert
Published: December 2017

Experimental skin burns induced by scalding may result in inadvertent damage to subdermal structures. To avoid this, a technique is used which employs the prescald injection of 200 ml of air subcutaneously in the dorsal skin region to be scalded (30–40% of body surface area). Lightly etherized rats preinsufflated with air and scalded at 90°C for 30 seconds showed a greater survival rate up to 72 hours postburn than noninsufflated, similarly scalded rats. The protective action of prescald subcutaneous air insufflation was demonstrated in a series of rats that was permitted food and water ad libitum after burn and in another series that was given, by gavage, a volume of 5% dextrose in 0.9% saline equivalent to 2% of the body weight immediately after burn but deprived of all food and fluid thereafter. At necropsy, air-insufflated, scalded rats showed no visible damage to underlying muscle; noninsufflated scalded rats did. This burn technic should prove valuable for studies on the possible release of deleterious factors from the site of the burn and studies on the enzymatic debridement of burned skin.
Incorporation of P32 in the Muscle by Normal and Thyrotoxic Resting Rats
Authors: Johnson Philip C. , Posey Audrey F. , Patrick Daniel R. , Caputto Ranwel
Published: December 2017

The muscles of thyrotoxic and normal rats were compared in their abilities to incorporate P32, injected intravenously, into their organic compounds. When the over-all incorporation is compared by determining the ratio of the specific activity of the P organic of the muscle to the specific activity of P inorganic of the blood, it is found that the process is faster in the thyrotoxic than in the normal. The data suggest that this results from faster penetration of P inorganic into the cells of the thyrotoxic muscle. However, the incorporation of intracellular P inorganic into P organic appears to be slower in the thyrotoxic animals. The ratio of the P32 incorporated into the organic components to the O2 consumed (somnolent metabolic rate) is lower in the thyrotoxic than in the normal rats.
Optical Anisotropy and Mechanical Behavior of Smooth Muscle of the Longitudinal Layer of Dog Ileum
Authors: Eberstein Arthur , Stacy Ralph W.
Published: December 2017

A method was devised and apparatus constructed for the rapid recording of optical phase retardation and tension of living muscle. Studies were made of tension and phase retardation of the longitudinal layer of smooth muscle from the dog ileum during a) slow stretch, b) rapid stretch and subsequent stress relaxation, and c) active contraction induced by acetylcholine. During slow stretch, phase retardation increased without appreciable increase in tension until the muscle length was nearly twice its length in the intestine. At greater lengths, tension increased, while phase retardation decreased with increasing length. When the muscle was stretched rapidly, the tension increased, then decreased as stress relaxation occurred. Phase retardation increased if the final length was equal to or less than that at which retardation peaked in slow stretches, but did not change if the final length was greater than the peaking length. During the stress relaxation which followed, phase retardation always decreased. In active contraction, phase retardation decreased.
Respiratory Studies on the Utilization of Carbohydrate After Adrenalectomy
Authors: Winternitz W. W. , Kline D. L.
Published: December 2017

Respiratory quotients and C14O2 production from 2-C14 pyruvate were studied in normal and adrenalectomized rats following subcutaneous epinephrine as a carbohydrate mobilizing agent. The adrenalectomized rats responded with a rise in R.Q. that was greater and more prolonged than that of the controls. They also expired more C14O2 than did the normal animals during the 4-hour period of study. These data are consistent with an increased rate of oxidation of carbohydrate by the adrenalectomized animal rather than increased lipogenesis.
Effect of Mercurial Diuretics Upon Oxidative Phosphorylation in Rat Kidney Mitochondria
Authors: Greif Roger L. , Jacobs Gloria S.
Published: December 2017

Administration of large doses of Hg203-labeled chlormerodrin to rats does not lower the P/O ratio of isolated kidney mitochondria. In vitro addition of chlormerodrin will lower the P/O ratio of rat kidney mitochondria, but only in concentrations greater than can be found by measurement of the mitochondrial radiomercury content following intramuscular injection. These techniques fail to demonstrate an in vivo effect of chlormerodrin upon oxidative phosphorylation by rat kidney mitochondria.
Effects of Salicylate on the Metabolic Activity of the Small Intestine of the Rat
Authors: Smith M. J. H.
Published: December 2017

The effects of salicylate on the transfer of glucose, sorbose and fluid across the intestinal wall and on the respiration, glycolysis and histological structure of sacs of everted small intestine from the rat, incubated under aerobic conditions, have been studied. 5 mm salicylate was found to inhibit the active transport of glucose and fluid, to increase the passive diffusion of sorbose, to decrease the oxygen uptake, to cause structural damage to the columnar epithelium lining the villi of the intestine, but not to affect the aerobic glycolysis of the sacs. It was concluded that the salicylate interfered with normal respiratory processes and hence with the supply of energy necessary for active transport processes in the intestinal preparation. The increased permeability of the sacs to sorbose may have resulted from the epithelial damage caused by the salicylate.
Effect of Galactose Ingestion on the Urinary Amino Acid Excretion in the Rat
Authors: Human L. E. , Middleton M. , Geiger E.
Published: December 2017

Groups of weanling rats were fed diets containing various levels of galactose or glucose or both. The excretion of amino acids was not affected by the type or quantity of ingested carbohydrate. It seems likely, therefore, that the aminoaciduria observed in galactosemic infants must be due to some cause other than the toxic effects of galactose itself or a competition for the renal reabsorption mechanism.
A Rapid Method for the Estimation of Fibrinolytic Changes in the Dog
Authors: Heinrich R. A. , Noe F. E. , Vonder Heide E. C.
Published: December 2017

The fibrinolytic system in the dog was studied for investigating possible etiological factors concerned with the bleeding diathesis observed following surgery and shock. Canine profibrinolysin is poorly activated with streptokinase and therefore provided the basis for the test procedure for fibrinolysin. Marked fibrinolytic activation was observed in dogs as early as 5 minutes after 2.5 mg/kg of protamine sulfate was given intravenously. Heparin produced inhibition of the fibrinolytic system. This protamine activation and heparin inhibition was shown both in vivo and in vitro. Test procedures are presented for the estimation of profibrinolysin, fibrinolysin and antifibrinolysin. Activation of the fibrinolytic system through surgery, hyperventilation or protamine sulfate, was followed by an increase in antilysin but no change in total fibrinolysin concentration was noted.
Release of C14-Histamine From Stomach and Intestine on Feeding
Authors: Schayer Richard W. , Ivy A. C.
Published: December 2017

Twenty-four male rats were divided into two groups of equal body weight. Food was withdrawn for approximately 16 hours when a subcutaneous injection of C14-2-l-histidine was made. Forty-eight hours after the withdrawal of food one group was fed for 24 hours and decapitated, the other group was fasted for the entire 72 hours and decapitated. The C14-histamine in the entire glandular stomach and the entire small intestine was decreased by feeding to the extent of 52% and 30%, respectively. Although some loss may have occurred as a result of desquamation, it is concluded that most of the loss of C14 histamine from the stomach and intestinal mucosa on feeding was due to its release into the blood stream.
Relationship Between Food Intake and Osmotic Effect of Dietary Carbohydrate
Authors: Harper A. E. , Spivey H. E.
Published: December 2017

The objective of this study was to determine whether differences in the food intake and in the rate of gain of rats fed on low protein diets containing different carbohydrates could be related to differences in the osmotic effects of the various carbohydrates. Rate of gain, food intake, stomach volume, dry weight and moisture content of the stomach contents, and the rate of stomach emptying were determined in rats at intervals after feeding low protein diets containing various carbohydrates. There was an inverse relationship between the capacity of the dietary carbohydrate to exert osmotic pressure and the food intake and rate of gain of rats fed for a single interval each day but the positions of glucose and sucrose in the series were reversed under conditions of ad libitum feeding. There was a direct relationship between the capacity of the dietary carbohydrate to exert osmotic pressure and the stomach volume and moisture content of the stomach contents. Rats could be trained to consume an adequate quantity of a diet in a limited time more readily if the osmotic capacity of the dietary carbohydrate was low.
Effects of Chlorpromazine and Autonomic Nervous System Blocking Agents in Combating Heat Stress
Authors: DeBias D. A. , Paschkis K. E. , Cantarow A.
Published: December 2017

The effects of autonomic blocking agents were studied on the survival rate of adrenalectomized rats exposed to 37.5°–38.5°C for 6 hours. Thorazine increased the survival rate of heat-stressed adrenalectomized rats, its effect being enhanced by addition of subeffective doses of hydrocortisone. Pendiomide ditartrate was ineffective when given alone, but was protective when added to subeffective doses of hydrocortisone. Dibenamine, Regitine and Pro-Banthine appeared to be detrimental under the experimental conditions employed. The mechanism underlying the protective effects of Thorazine and Pendiomide apparently does not involve body temperature control. The observations suggest that the mechanisms of protection against heat and cold exposure differ from those involved in protection against other types of stress.
Temperature Effects on Phosphate Uptake and Release in the Isolated Rabbit Heart
Authors: Omachi Akira , Ginski John M.
Published: December 2017

Radiophosphate uptake by the isolated rabbit heart fails to increase with temperature when the organ is perfused for 1 hour with Ringer-Locke's solution containing 5 µg P/ml. The low perfusate oxygen and phosphate concentrations appear to be partly responsible for this result. Phosphate concentration in the effluent perfusate increases with temperature. Thus, phosphate release does not appear to be immediately dependent upon entrance of phosphate. The lower total acid-soluble phosphate content at 37° compared to 26° is accounted for largely by differences in phosphocreatine and adenosine polyphosphate concentrations. The underlying basis for cellular release of phosphate may therefore be related to degradation of high energy phosphate.
Mechanisms of Respiratory Inhibition Produced by Sudden Aortic Obstruction
Authors: Gilfoil Thomas M. , Schopp Robert T. , Norris Gail R. , Youmans W. B.
Published: December 2017

External constriction of the descending aorta elicits immediate inhibition of breathing in dogs under Pentothal-chloralose anesthesia both before and after sino-aortic denervation. Impulses initiated by traction of a ligature on the aorta are conducted into the thoracic part of the cord. There is no indication that this mechanism is activated in experiments involving internal occlusion in the innervated animals. Internal occlusion of the descending aorta elicits inhibition of breathing in dogs under morphine sulfate-chloralose anesthesia having all neural pathways intact. The inhibition is related in large part to reflexes from the sino-aortic zones. In the majority of dogs studied the delayed inhibition of breathing following internal occlusion of the descending aorta was greatly reduced but usually not entirely eliminated by sino-aortic denervation. Therefore, some other respiration-inhibiting mechanism is involved. That the respiratory center may be relatively insensitive to changes in blood flow under the conditions of these experiments is indicated by the fact that in individual cases sudden severe changes in blood pressure in sino-aortic denervated animals were not accompanied by changes in respiration.
Transfer of Histidine and Xylose Across the Placenta and Into the Red Blood Cell and Amniotic Fluids
Authors: Dancis Joseph , Olsen Gordon , Folkart Gladys
Published: December 2017

The transfer of l-histidine and d-xylose across the placenta and into the red blood cell and amniotic fluids was investigated in the guinea pig to see if a correlation existed that might be adapted to a measure of placental function. There was a rough correlation in the permeability of the red blood cell and the placenta to both substances but it was not constant. Insufficient l-histidine was transferred into the amniotic fluid under the conditions of these experiments to be accurately measured. d-Xylose was demonstrable in the amniotic fluid in relatively low concentrations, but there was no evident relation to placental permeability.
Fatty Acid Oxidation by Skeletal Muscle During Rest and Activity
Authors: Fritz Irving B. , Davis Don G. , Holtrop Robert H. , Dundee Harold
Published: December 2017

The metabolism of C14-labeled acetate, octanoate and palmitate by isolated skeletal muscle (latissimus dorsi and diaphragm) from normal, fed rats has been examined. The rates at which these substrates were converted to C14O2 have been shown to vary with concentration, temperature, functional state of the muscle, and the presence of albumin. Increased concentration of fatty acids led to enhanced conversion of substrate to C14O2. Electrical stimulation of muscles under tension resulted in approximately a 60% increase in oxygen consumption and about a 100% rise in fatty acid oxidation. The addition of glucose did not alter the rate of fatty acid metabolism by muscle. The addition of bovine albumin at concentrations up to approximately 1 µm albumin/7 µm palmitate resulted in augmented palmitic acid oxidation. However, at concentrations of albumin greater than 1 µm albumin/7 µm palmitate, palmitic acid degradation by resting diaphragm was inhibited, suggesting a firmer binding of fatty acid to albumin. The Q10 for palmitic acid oxidation by resting diaphragm was 2.23 in the absence of added albumin between 25° and 37°C. The data are discussed in relation to the present concepts of fat metabolism and transport in vivo. It is suggested that fat degradation in isolated muscle may provide an energy source during activity.
Effect of Prior Injections of HgCl2 on Renal Pickup of Mercury From Subsequent Injections
Authors: Surtshin A. , Audia Marino , White H. L.
Published: December 2017

If sucrose-fed rats be given 3 mg HgCl2/ kg, many of them will survive further doses after return to chow. The 24-hour renal pickup of mercury from a final dose of Hg*Cl2 by such rats is less than that from an initial injection by chow-fed rats. Evidence is presented that this is due to the large amount of mercury from prior injection remaining in the kidneys rather than to a diminished ability of the kidneys to bind mercury. A true increase in the kidney's tolerance for mercury is indicated.
Ovulation Induced by Hypothalamic Stimulation in the Anesthetized Rat
Authors: Critchlow Vaughn
Published: December 2017

In the present study, employing 38 female rats with normal estrous cycles, electrical stimulation during pentobarbital anesthesia was effective in inducing ovulation. It was found that bilateral stimulation of the hypothalamus in anesthetized proestrous rats during the ‘critical period’ and within certain spatial and current limitations consistently caused ovulation. The area that appears most responsive is medially situated in the ventral hypothalamus, between the optic chiasma and the infundibular stalk.
In Vitro Inactivation of Three Naturally Occurring Estrogens by Liver From Fetal, Newborn, Day-Old and Adult Rats
Authors: Brown Frieda Urey , Meyer Roland K.
Published: December 2017

In vitro incubation of estrogens with liver from adult or day-old rats decreased the uterotrophic activity of estrone and estradiol-17ß more than did liver from newborn or fetal rats. The action of liver preparations on estradiol-17α was minimal. The microsomes from fetal liver were shown to be deficient in their ability to inactivate estradiol-17ß. The estrogen inactivating system of fetal liver, particularly the microsomal fraction, was less effective than that of adult liver. The marked increase in potency which occurred during the first 24 hours after birth may well have been due to partial maturation of this microsomal system.
Effect of Certain Histaminase Inhibitors on Gastric Secretion
Authors: Liepins Kurts W. , Ivy A. C. , Suzuki Ryuta
Published: December 2017

Dogs with Heidenhain pouches were used to study the effect of aminoguanidine (AG) and iproniazid (IPN) (1-isonicotinyl-2-isopropylhydrazine) (‘Marsilid’) on gastric secretion. AG and IPN given subcutaneously or orally were found to stimulate the basal secretion and to augment the gastric secretory response to a meal. In vitro studies have shown that AG is a diamino oxidase (DO) inhibitor and IPN is both a di- and monoamino oxidase (MO) inhibitor. IPN augments gastric secretion by its DO and not its MO inhibitor activity. Doses of IPN which cause evidences of mild toxicity depress gastric secretion. Evidence of the accumulative action of IPN on gastric secretion was obtained. Dogs vary considerably in their sensitivity to iproniazid. Since inflammation increases sensitivity to the gastric augmentory effects of both AG and IPN, and since man is 10 times more sensitive to histamine than the dog, it is suggested that the use of iproniazid in the treatment of active tuberculosis should augment gastric secretion, unless evidences of toxicity occur, and that the drug should be used cautiously in peptic ulcer patients. B1-pyrimidine, a DO inhibitor, given subcutaneously slightly augments the secretory response to a meal in a sensitive dog.
Displacement Characteristics of Intracellularly Accumulated p-Aminohippurate in a Mammalian Renal Transport System in Vitro
Authors: Copenhaver J. H. , Forster Roy P.
Published: December 2017

Studies on the displacement of actively transported organic acids, subsequent to their intracellular accumulation by thin slices of rabbit renal cortex, indicate the existence of a carrier or trapping mechanism. Displacement of accumulated PAH from carrier is facilitated by the simultaneous presence of transfer competitors. Those competitors which are least actively transported are generally the most effective in causing run-out out of the more actively transported members of the series. Competitive displacement of PAH does not occur in the cold. 2, 4-Dinitrophenol, while very effective in causing run-out of PAH at room temperature, is without such effect in the cold. Metabolic intermediates such as acetate and pyruvate which stimulate the initial uptake of PAH inhibit the loss of intracellularly accumulated PAH. Others such as succinate and α-ketoglutarate which inhibit uptake of PAH facilitate its run-out. None of these metabolites affects the competitive displacement of PAH at 0°C.
Sensitization by Insulin to Dextran Anaphylactoid Inflammation in Spinal Rats
Authors: Adamkiewicz V. W. , Langlois Y. L. , Poirier L. J.
Published: December 2017

Insulin sensitizes normal rats considerably to the ‘anaphylactoid’ inflammation produced by the administration of dextran. This sensitization manifests itself to the same extent in the spinal rats. Therefore, the sensitization takes place despite the interruption of the spinal nervous pathways and despite the stress.
Effect of Dietary Fats on Glucose Tolerance and Alloxan Diabetes
Authors: Barboriak Joseph J. , Krehl Willard A.
Published: December 2017

Effects of certain animal and vegetable fats, i.e. lard, butter, corn oil, coconut oil, cottonseed oil, margarine and Crisco, on glucose tolerance and on the toxic and diabetogenic action of alloxan have been investigated in experiments on rats. Experimental diets, containing 61.2% of the fats under test, were fed for 6, 7, 9 and 36 weeks and 14 months, respectively. In two long-term series, the hyperglycemia following glucose injection (1 gm/kg body weight, intraperitoneally) was more pronounced in groups fed margarine or Crisco diets than in animals receiving lard or butter diets. In the short-term series, the difference between these two groups of fats in the increase of blood sugar levels was not significant. The adverse effects of alloxan were also influenced by the type of fat in the diet; in one series both the incidence of diabetes and the mortality rate were higher in the corn oil group than in the butter- and coconut oil-fed groups; in another series only the mortality rate was affected.
Parotid Clearance of Sodium and Potassium
Authors: Langley L. L. , Gunthorpe C. H. , Beall W. A.
Published: December 2017

A current hypothesis suggests that the mechanism of salivary production involves the formulation of a precursor solution followed by reabsorption of sodium and water but not potassium. Since this is similar to kidney physiology, clearance techniques were used to test the hypothesis. At parotid flow rates below about 0.2 cc/min. the concentration of Na varies directly and that of K indirectly with the flow. At higher rates the K concentration is independent of the flow and closely approximates that of the plasma. Potassium clearance, then, is independent of flow only at very low flows. The concentration of Na in parotid saliva varies with that in the plasma. Extrapolation of the curve cuts the abscissa at a point indicating that if the plasma Na concentration were reduced below approximately 100 mEq/l. no Na would appear in the saliva. The relationship between plasma concentration and the saliva Na/plasma Na ratio is an ascending curve. As the plasma K concentration increases so does the concentration in the parotid saliva. Extrapolation of this curve approaches the origin. The saliva K/plasma K ratio is independent of the plasma K concentration. When K is infused salivary flow rate increases. The infusion of Na decreases flow. These results are consistent with the selective reabsorption theory at low flow rates but there must be another mechanism to explain the findings at higher flows. It is suggested that the influence of Na and K infusion on salivation may be, at least partially, indirect.
Effect of body weight and sex on activity of enzymes involved in amino acid metabolism
Authors: Lin Edmund C. C. , Rivlin Richard S. , Knox W. Eugene
Published: December 2017

The total body activities of four transaminases and two oxidases concerned with aromatic amino acid metabolism were studied in five species of mammals of varying size to test for correlations between total body enzyme activity and body weight. It was found that as a general rule the following expression was obeyed: enzyme x weight k = constant (the weight parity expression), where k varied numerically from –0.25 to –0.73 depending on the enzyme. The two oxidases had values which varied from –0.71 to –0.73 which are very close to the value –0.73 established for total oxygen utilization as a function of body weight. The use of the weight parity expression permitted the analysis within a given species of enzyme activities in animals with different body weights. Such an analysis proved useful in distinguishing an enzyme, tyrosine-α-ketoglutarate transaminase, whose level showed a true sex difference from others whose levels showed apparent sex differences which were actually referable to the smaller body weights of the females. Direct experimentation involving castration and hormone treatment substantiated this conclusion and identified testosterone as the important controlling factor. This sex difference was explicable by the known effects of adrenal cortical hormones on the level of this enzyme and by the reported differences in the rate of hepatic metabolism of adrenal cortical hormone in male and female animals.
Change in blood clotting time of rats exposed to a particular form of stress
Authors: De Long Erika , Uhley Herman N. , Friedman Meyer
Published: December 2017

Rats were subjected to a form of stress which involved a sense of urgency and apprehension by periodically and alternately charging half of the floor of a specially constructed cage, forcing migration to the uncharged areas. Three groups of experimental rats were placed in the cage for 1, 3 and 6 hours, respectively. At the end of the stress period the clotting time of the experimental rats was taken, and compared to controls. It was found that in addition to marked behavioral differences, the stressed rats exhibited significant hastening of blood coagulation.
Independence of activation of the fibrinolytic system from certain immunologic systems
Authors: Kolmen S. N. , Celander D. R. , Guest M. Mason
Published: December 2017

Activation of the immunologic system either in vitro or in vivo results in nearly complete consumption of complement without activation of the fibrinolytic system. However complement activity decreased upon the induction of fibrinolytic activity even in the absence of an antigen-antibody reaction. Presumably this is due to proteolysis of some part of the complement complex since complement activity was found to be destroyed in the presence of small quantities of purified fibrinolysin. These observations are consistent with the conclusion that a) the components of complement and those of the fibrinolytic system are separate and discrete entities; b) that reactions involving complement fixation and activation do not directly influence the fibrinolytic system; and c) that activation of the fibrinolytic system results in decreases in complement through proteolysis of one or more of its components by the fibrinolysin which develops.
Effects of altitude acclimatization on rat myoglobin. Effect of viscosity and acclimatization on myoglobin reaction rates
Authors: Strother G. K. , Ackerman Eugene , Anthony Adam , Strickland E. Hardin
Published: December 2017

Equipment and procedure used in the determination of myoglobin-oxygen reaction rate constants in viscous media are described briefly. The rate constants were determined for purified extracts of myoglobin from control and acclimatized rats over the viscosity range 0.87–53 centipoise. Glycerol-water mixtures were used as the viscous media. The reaction rates were found to vary with the viscosity of the suspending medium in a nonlinear fashion. No difference was observed in the reaction rates for acclimatized versus control rats using skeletal muscle extracts. A preliminary investigation of heart muscle extracts indicates a decrease in the oxygen association rate for the acclimatized rats. The significance of the kinetic data is discussed.
Effect of saturated and unsaturated fats on fecal excretion of end products of cholesterol-4-C14 metabolism in the rat
Authors: Wilson Jean D. , Siperstein Marvin D.
Published: December 2017

The influence of fat on the excretion into feces of the end products of cholesterol-4-C14 metabolism was studied in rats fed diets which were either fat-free or contained lard or corn oil at the 20% or 30% level. Total recovery of injected C14 was consistently higher in rats fed corn oil and lard than in rats fed fat-free diets. No consistent differences were noted among the three groups in the excretion of C14 in either bile acids or digitonin-precipitable neutral sterols. However, in rats fed corn oil there was a marked increase in the excretion of C14 in nondigitonin-precipitable neutral sterols, amounting in these animals to as much as 54% of the excreted C14. These data are interpreted as demonstrating that the excretion of nondigitonin-precipitable neutral sterols may under some circumstances be a major pathway for cholesterol excretion. Furthermore, the marked acceleration in the excretion of nondigitonin-precipitable sterols may account in part for the cholesterol-lowering effect of unsaturated fats.
Effect of saturated and unsaturated fats on hepatic synthesis and biliary excretion of cholesterol by the rat
Authors: Wilson Jean D. , Siperstein Marvin D.
Published: December 2017

In an attempt to elucidate the mechanisms by which saturated and unsaturated fats influence cholesterol metabolism, cholesterol synthesis in rat liver slices and the excretion of cholesterol end products into the bile of rats was studied during variations in the type and quantity of dietary fat. Neither 30% lard nor 30% corn oil diets had any effect on either the excretion of total cholesterol-C14 end products or of cholesterol itself into bile. Furthermore, the feeding of lard or corn oil, at either the 10% or 30% level, had no effect on the rate of conversion of acetate or mevalonate to cholesterol. These studies are interpreted as suggesting that the effects of saturated and unsaturated fats on cholesterol levels in rats are mediated at some phase of cholesterol metabolism other than the hepatic synthesis or hepatic degradation and excretion of this sterol.
Effects of chronic treatment with carbutamide on distribution and biosynthesis of fatty acids and cholesterol in obese-hyperglycemic mice
Authors: Christophe Jean , Mayer Jean
Published: December 2017

Oral treatment with carbutamide (BZ-55) for 7 weeks (2.5 gm/kg of ground chow) left the food intake and rate of weight gain of obese-hyperglycemic mice and lean littermates unmodified as compared with untreated controls. Obese-hyperglycemic animals, after 49 days of treatment showed the usual distribution and rate of biosynthesis of fatty acids and cholesterol in the liver and carcass. Liver hypertrophy, marked increase in serum cholesterol levels and lack of improvement of the ‘diabetes’ were also observed in these animals. Lean littermates similarly treated showed no modification in the distribution of fatty acids and cholesterol and in the biosynthesis of fatty acids in the liver and carcass. An increase in hepatic cholesterologenesis, liver hypertrophy, some increase in serum cholesterol levels and a small but significant increase in the blood sugar levels were noticed.
Influence of prolonged hypothermia and hyperthermia on cardiac response to injected potassium
Authors: Spurr G. B. , Barlow George , Lambert Hayden
Published: December 2017

Left ventricular Na, K, Cl and H2O and plasma Na, K and Cl have been measured in normothermic dogs, animals cooled to a rectal temperature of 25°C for 2 hours, and dogs maintained at a rectal temperature of 41.5°C for 1 hour. These three main groups are subdivided into a control group killed with pentobarbital sodium prior to obtaining cardiac tissue, and dogs that received an intravenous injection of 11.2% KCl at a rate of 0.5 ml/kg/min. until ventricular fibrillation or cardiac arrest occurred. The method employed to measure cardiac sensitivity to K is criticized. Despite the criticisms, the data suggest a reduced sensitivity of hypothermic hearts and an increased sensitivity of hyperthermic hearts to injected KCl. The rapid rate of injection of KCl employed in these experiments resulted in a high incidence of ventricular fibrillation except in one group of hypothermic dogs in which cardiac arrest was predominant. It is concluded that this predominance was the result of a slowed rate of supply of the injected KCl to cardiac tissue probably resulting from reduced coronary blood flow.
Hypothermia: effects of hypertonic solutions on incidence of ventricular fibrillation
Authors: Beavers W. Robert
Published: December 2017

Mongrel dogs cooled to terminus exhibited a 91% incidence of ventricular fibrillation. Animals receiving 25% glucose or 50% sucrose intravenously during cooling did not fibrillate but terminated in asystole. In untreated cooled animals, plasma concentrations decreased, and plasma calcium and sodium were unaltered. Dogs receiving hypertonic glucose or sucrose had decreased plasma calcium and sodium levels, but normal potassium concentrations at lower body temperatures. The possible mechanisms by which hypertonic fluids decrease excessive cardiac excitability are discussed.
Fibrinolytic system of guinea pig serum
Authors: Latallo Zbigniew , Niewiarowski Stefan , Copley Alfred L.
Published: December 2017

Comparative studies on 10 mammals showed that, in contrast to all the others, guinea pig serum alone, on precipitation with acetic acid, pH 5.3–5.4 at 4°C, yielded a euglobulin with high spontaneous fibrinolytic activity. Fibrinolytic and proteolytic activities of guinea pig, bovine and human euglobulins after addition of streptokinase (SK), SK-human plasminogen mixture, and without any activators were compared; antiplasmin activity was also investigated. When guinea pig serum was substituted for human serum in a mixture of the latter with SK, there was no activation of bovine plasminogen. A plasmin-antiplasmin complex may be the chief component of the guinea pig serum fibrinolytic system.
Effect of prolonged cold exposure on oxidative phosphorylation and adenosinetriphosphatase activity of rat liver tissue
Authors: Hannon John P.
Published: December 2017

Liver homogenates from control and one month cold-exposed (5 ± 1°C) rats were assayed for the P/O ratios characteristic of succinate and ß-hydroxybutyrate oxidations and for the level of adenosinetriphosphatase activity. With both substrates a significant lowering of the P/O ratio was observed in the cold-exposed group. Measurements of adenosinetriphosphatase activity in water homogenates showed that calcium and magnesium had strong activating effects. Little difference was found between control and experimental preparations except where both ions were used simultaneously. Here, the tissue from the cold-exposed group exhibited a slightly lower activity than the controls.
Effects of altitude and of anesthesia on brain electrolytes and lactic acid
Authors: Van Fossan Donald D. , Biddulph Clyde
Published: December 2017

The concentration of lactic acid, sodium, potassium and calcium was measured in four structures of the brain 3 hours after death in anesthetized and unanesthetized dogs which had been subjected to simulated altitude and ground level control protocols for 15 minutes. The effect of the simulated altitude was elevation of a) the sodium concentration in the corona radiata but not in the cerebral cortex or caudate nucleus, b) the calcium concentration in the cortex, corona radiata and caudate nucleus and c) the lactic acid concentration in all the tissues. No potassium changes were noted. The effect of the anesthesia was very slight and only indirectly detectable. The sampling problem was studied and caudate nucleus and cortex recommended as sampling sites for the detection of hypoxia by lactic acid elevation if a whole hemisphere cannot be used. It is pointed out that accuracy in diagnosing ante mortem hypoxia depends upon discrete anatomical sampling since lactic acid is not evenly distributed within the brain. A chemical approach to give compensation for the uneven distribution of lactic acid is presented.
Distribution of amylase in the gastrointestinal tract of the rat
Authors: McGeachin Robert L. , Ford Norwood K.
Published: December 2017

Amylase levels of the serum, stomach, duodenum, jejunum, cecum and colon in rats were determined by Van Loon's amyloclastic method. The rats used were in several categories: normal, fasted 7 days, with liver damaged by N-nitrosodimethylamine, pancreatectomized and both salivarectomized and pancreatectomized. Amylase was found throughout the gastrointestinal tract in all rats, being highest in the normals. In the normal rats, the amylase level of the jejunum was slightly higher than that of the duodenum. The same is true for the pancreatectomized and pancreatectomized-salivarectomized rats but in the fasted rats and those with liver damage, the reverse is true. Despite removal of the known sources of amylase, the enzyme persisted in the gastrointestinal tract of salivarectomized-pancreatectomized rats. It is believed that the duodenum and jejunum are sites of amylase production even though much of that found in the normal rat's gastrointestinal tract is pancreatic in origin. These surgically treated animals were able to digest starch.
Factors contributing to the successful reanimation of mice cooled to less than 1°C
Authors: Miller James A. , Miller Faith S.
Published: December 2017

Nearly all mice cooled to less than 1°C can be reanimated if first cooled slowly to less than 20°C in a sealed vessel of appropriate size. During this period the O2 content of the vessel falls to 6%, the CO2 increases to 11% and the humidity to saturation. An analysis shows that hypercapnia is chiefly responsible for the success of the method, though hypoxia and increased humidity also are beneficial. This holds whether the percentage of recoveries, time and temperature of recovery of postural reflexes, or incidence of hind leg weakness is used as an index of success. During resuscitation the animals received artificial respiration with 100% O2, 95% O2 + 5% CO2, 90% O2 + 10% CO2, or air. Comparisons of percentage of recoveries, long term survivals and uninjured hind legs show that 95% O2 + 5% CO2 gives the best results and 100% O2 the poorest. These findings demonstrate the benefits of CO2 in deep hypothermia.