bluuebunny/crossref_metadata_2025 huggingface dataset:
Effect of Histamine on Electrocardiograms and Serum Electrolytes of Intact, Cortisone-Treated and Adrenalectomized Hamsters
Authors: Sudak Frederick N. , Wyman Leland C. , Fulton George P.
Published: December 2017

Following toxic doses of histamine in golden hamsters there was progressively increasing bradycardia in those which died and a compensatory tachycardia in survivors. The T wave of the EKG increased, especially in those animals which succumbed, and decreased as terminus approached. Except for terminal lowering there were no striking changes in the P wave. Other changes were occasional Q waves, lowered R waves and deeper S waves, and impaired conduction. Pretreatment of intact hamsters with 12 daily doses of cortisone acetate lowered both serum sodium and potassium. Hyponatremia and hyperpotassemia were present terminally in intact hamsters dying from histamine intoxication. Pretreatment with cortisone tended to alleviate these changes but did not entirely prevent the terminal rise in serum potassium. Adrenalectomized hamsters exhibited hyponatremia and hyperpotassemia, both becoming greater as death approached. Maintenance therapy with cortisone did not restore a normal serum sodium but did reduce serum potassium to normal or below. Adrenalectomized hamsters poisoned by small doses of histamine had EKG and serum electrolyte changes similar to those dying from adrenal insufficiency. Replacement therapy prevented these changes.
Irradiation of the Gastrointestinal Tract of the Rat by Ingested Ruthenium-106
Authors: Thompson Roy C. , Hollis O. L.
Published: December 2017

Rats were killed at intervals from 35 minutes to 30 hours following intragastric administration of a solution of Ru106 chloride. Distribution of Ru106 within the various segments of the gastrointestinal tract, and distribution of tract contents were determined. Results are interpreted in terms of the rate of passage of material through the gastrointestinal tract, and the resulting radiation dose to the various segments of the tract. The largest radiation dose is delivered to the lower large intestine. Doses to other segments of the tract are lower by as much as a factor of five. There appears to be no significant hold-up of the radioisotope due to absorption on the intestinal wall.
Effects of Epinephrine on Metabolism of Glucose of Normal Dogs
Authors: Dickman Sherman R. , Wiest Walter G. , Eik-Nes Kristen
Published: December 2017

Following the intravenous administration of a tracer dose of C14 glucose, nonradioactive glucose was infused in normal, anesthetized dogs over a 2-hour period with and without the concomitant administration of epinephrine. Blood samples were obtained from the portal vein, hepatic vein, femoral artery and femoral vein at various periods after the start of the infusion. The blood glucose concentration was higher in the epinephrine-treated animals than in the controls and blood glucose radioactivity remained at consistently higher levels in the former group. Blood glucose specific activity, however, dropped faster and attained lower values in the controls. Blood lactate levels were higher in the epinephrine-treated animals. The individual and cumulative specific activities of expired CO2 were appreciably lower in the epinephrine-treated group. The results are interpreted as demonstrating a dual effect of epinephrine; decrease in glucose uptake by tissues and an increase in lactate entry into the blood.
Conformational Specificity in a Biological Sugar Transport System
Authors: LeFevre P. G. , Marshall J. K.
Published: December 2017

The ‘carrier’ system in the surface of the human erythrocyte, facilitating passage of monosaccharides through the cell membrane, reacts preferentially with those sugars in which the pyranose ring tends to assume the particular ‘chair’ shape designated by Reeves as the ‘C1’ conformation. This novel type of steric specificity was revealed in a comparative study of fourteen aldoses (6 pentoses, 5 hexoses, and 3 deoxyhexoses), in which the dissociation constants of the carrier-sugar complexes were derived from the kinetics of the transfer process and of the competitive inhibition by phloretin. The sequence of increasing affinities thus determined paralleled the sequence of increasing relative stability in the C1 conformation as dictated by the distribution of substituent groups between axial and equatorial positions on the ring. Sugars predominantly stable in the other chair conformation (1C) showed extremely low affinity. Since no instance of biological utilization of the latter sugars has apparently yet been found, it is suggested that the necessity for the C1 ring-shape is basic in all enzymic reactions with pyranoses. However, most systems show further special requirements for particular side-group arrangements, which are superimposed on the primary ring specificity seen in the red cell's sugar transport system.
Effect of Thiouracil on Serum and Liver Cholesterol of the Athyreotic Rat
Authors: Duncan Charles H. , Best Maurice M.
Published: December 2017

Thiouracil (0.5%) was added to the diet of athyreotic rats for a 2-week period and serum and liver cholesterol concentrations compared to those of athyreotic controls. Thiouracil administration resulted in an increase in mean serum cholesterol and a decrease in mean liver cholesterol. Hepatic synthesis of cholesterol from C14 acetate was not significantly influenced by thiouracil. It is concluded that thiouracil, by altering the plasma-liver partition of cholesterol, exerts a hypercholesterolemic effect which is independent of its antithyroid action.
Emotional Behavior Produced by Hypothalamic Stimulation
Authors: Nakao H.
Published: December 2017

In unanesthetized, unrestrained cats, the hypothalamus was stimulated with implanted electrodes. Responses depended on electrode position, and were classified as flight or aggressive reactions. Aggressive responses were, in general, elicited from middle hypothalamic stimulus sites, whereas flight reactions were more commonly elicited from rostral hypothalamic or preoptic sites. Both flight and attack were well-directed and purposeful. In some animals, conditioned responses to a buzzer were established with hypothalamic stimulation as the US. Hypothalamic stimulation was also successfully used to establish a conditioned avoidance response (food avoidance, compartment preference test). Stimulation at electrode sites producing flight reactions elicited a response (paddle-pushing) previously established to avoid a painful shock to the feet. The data suggest that hypothalamic stimulation arouses an affective experience closely akin to that produced by natural stimuli. It is felt that the possibility exists of cortical participation in hypothalamic-induced affective behavior.
Effects of Induced Hypothermia on Subcortical Evoked Potentials in the Cat
Authors: Stevenson George C. , Collins William F. , Randt Clark T. , Saurwein Thomas D.
Published: December 2017

The effects of induced hypothermia in the unanesthetized immobilized cat on somatic afferent evoked potentials from the posteroventral lateral nucleus of the thalamus, periaqueductal midbrain reticular formation and dorsal column of the spinal cord were studied in 28 cats. At a rectal temperature of 23°C, marked depression of the responses recorded from all loci was demonstrable. The afferent midbrain reticular formation was demonstrated to be more sensitive to hypothermia than the thalamic relay nucleus. Augmentation of the spinal cord dorsal column evoked potentials was noted between 33°C and 25°C. Conduction time measurements indicated that between 37°C and 27°C the velocity of transmission along the nerve fibers is more affected than transmission across a synapse.
Intestinal Blood Flow as Influenced by Vascular and Motor Reactions to Acetylcholine and Carbon Dioxide
Authors: Bean John W. , Sidky Mahmoud M.
Published: December 2017

The effect of acetylcholine on intestinal blood flow and motor activity was studied experimentally by direct continuous recordings of blood flow with thermopile and drop methods in loops of dog intestine completely isolated and set up in a plethysmographic chamber maintained at body temperature or left in situ but completely isolated except for extrinsic nerves. In each case the segments were perfused continuously with heparinized dog blood under constant pulsatile pressure. Injection of 0.3 cc of acetylcholine hydrochloride in dilutions of from 1:104 to 1:107 into the inflow blood caused local vasodilatation and increased blood flow the onset of which invariably preceded the motor reaction, if any. Strong motor reactions and tonic contractions induced by the larger dosages diminished the intestinal blood flow by passive compression of intestinal vessels. Continued augmentation of flow following cessation of these motor reactions is attributed to a persistence of vasodilator action of acetylcholine and to a presumed increased release of metabolic vasodilator substances. Atropinization eliminated to a very large degree the motor reaction to smaller doses of acetylcholine but did not prevent the vasodilator reaction. Hypercapnemia agumented both of these reactions to acetylcholine; this lends support to the interpretation that CO2 acts as a physiological anticholinesterase presumably by virtue of its acid properties.
Localization of Diuretic Action of Chlormerodrin in the Nephron of the Dog
Authors: Kessler R. H. , Hierholzer K. , Gurd R. S. , Pitts R. F.
Published: December 2017

The stop flow method of Malvin, Sullivan and Wilde ( Physiologist 1:58, 1957) has been applied in a study to localize the diuretic action of chlormerodrin in the nephron of the dog. It has been observed that under stop flow conditions, chlormerodrin reduces both the U/P ratio for creatinine in the proximal tubule and the gradient against which the proximal tubule can reabsorb sodium and chloride ions. These results are interpreted as indicating partial inhibition of active transport of sodium and/or chloride ions in the proximal segment of the nephron and equivalent reduction in the osmotic back flow of water. The reabsorption of sodium and/or chloride ions is inhibited in the same portion of the tubule which secretes the diuretic and which secretes p-aminohippurate. These experiments provide no evidence for inhibition of reabsorption of sodium of sodium and chloride ions by chlormerodrin in the distal tubule.
Graphical Placement of Transport Segments Along the Nephron From Urine Concentration Pattern Developed With Stop Flow Technique
Authors: Wilde Walter S. , Malvin Richard L.
Published: December 2017

The authors characterize transport within segments at points along the nephron by the concentration pattern developed along the renal tubule during stopped flow (brief ureteral occlusion during osmotic diuresis in dogs). The pattern is caught in serial urine samples on reinstatement of flow. They here develop a system of graphical construction which places active transport segments of proper length and position to account for the concentration patterns developed for the substances: Sodium, glucose, phosphate and para-aminohippurate (PAH). The system is based on mixing phenomena as nephrons of different length deliver their fluid content into mixed samples. Glucose reabsorption, phosphate reabsorption and PAH secretion occur in identical proximal segments, containing 45% of the total stop flow nephron volume. A far distal area for very effective active sodium reabsorption contains about 29% of the occluded nephron volume. The sodium concentration pattern does not delineate its own proximal segment but forms a plateau in that area. This results from the fact that proximal concentrations are not lowered during stop flow but remain the same as in new flow and free flow proximal fluid, no lower than the 30–60 mm concentration of free flow urine itself, considerably higher if distal removal of Na occurs during the new outflow.
Bile Acid-Lipoprotein Relationships Using Cholic Acid-24-C14
Authors: Portman Oscar W. , Murphy Paul
Published: December 2017

The sera of rats with biliary obstruction of short duration and of rats fed diets containing cholesterol and cholic acid were analyzed for lipoprotein concentrations and lipoprotein composition by ultracentrifugal techniques. Both rats with biliary obstruction and those that were fed cholesterol and cholic acid had beta lipoproteins with increased cholesterol composition (relative to total beta lipoproteins and to protein content of the lipoproteins). When cholate-24-C14 was injected intraperitoneally into rats with biliary obstruction, a considerable portion of the radioactivity remained in the sera as taurocholate 6 hours after administration. Isolation and purification of the alpha and beta lipoproteins from such rats indicated the association of little or no radioactivity. The radioactivity in whole sera from these rats and in human sera incubated with radiocholate was largely nondialyzable and had electrophoretic mobility similar to that of serum albumin. The incubation of human sera with different bile salts had no effect on concentrations or mobility of beta lipoproteins (ultracentrifuge) or proteins (electrophoresis).
Distribution of ‘Intrinsic Factor’ Activity
Authors: Herbert Victor , Spaet Theodore H.
Published: December 2017

After preincubation with hog intrinsic factor concentrate (HIFC), marked enhancement of Co60-labeled vitamin B12 uptake at 0°C by rat and human liver slices and by segments of rat small intestine was observable. No such marked enhancement by HIFC was observable in rat kidney, heart or spleen slices. After preincubation with serum from normal human beings or patients with pernicious anemia, slight enhancement of Co60-B12 uptake by rat liver slices was noted; marked enhancement was noted after preincubation with a 15-fold concentrate of normal human serum. The hypothesis is presented that there may exist a ‘circulating intrinsic factor’ involved in the selective deposition of vitamin B12 in the human liver.
Excretion of Free Histamine in Urine During Gastric Secretion Stimulated by Humoral Mechanisms
Authors: Updike Edwin H. , Code Charles F. , Hallenbeck George A.
Published: December 2017

This study was done to determine whether, after a meat meal, the outputs of acid in gastric juice and free histamine in urine are related and whether the output of free urinary histamine is increased after transplantation of the gastric antrum to the colon. Dogs with separated gastric pouches (Heidenhain) were used. Gastric juice and urine were collected at hourly intervals before and after the ingestion of the meal and for 24-hour periods before and after transplantation of the gastric antrum to the colon. Similar collections were made when histamine was injected intravenously at different rates. A rough temporal correlation was found between the outputs of HCl in gastric juice and free histamine in the urine after the meal of meat. There was not a significant increase in the 24-hour output of free histamine in the urine of the dogs in which a modest hypersecretion developed following transplantation of the gastric antrum to the colon.
Intrinsic Periodicity of the Pontile Pneumotaxic Mechanism
Authors: Cohen Morton I.
Published: December 2017

Microelectrode explorations in the region of the pneumotaxic center (dorsolateral rostral pons) have revealed the presence of numerous neurons discharging synchronously with respiration. To determine whether these discharges are intrinsic in origin or are activated by impulses from other regions, half of the pons was isolated by means of sectioning procedures, and the isolated region was explored for periodic discharges with microelectrodes. In preparations where hemisections were made but connections across the mid-line were left intact, discharges synchronous with respiration were found. In addition, two types of periodic discharge not synchronous with respiration were found; however, there is no conclusive evidence which relates these discharges to respiration. In the completely isolated hemi-pons (hemisection plus sagittal section), no definitely periodic discharges were found. It is therefore concluded that the periodic respiratory discharges in the pneumotaxic center are probably not intrinsic in origin, but are dependent on connections with other regions of the brain stem.
Resting Metabolism of Immature Nerve Fibers in the Developing Chick
Authors: Carpenter F. G.
Published: December 2017

In peripheral nerve excised from incubating chicks, the resting oxygen utilization per unit weight of axons and their supporting elements has been found to decrease during their development into the adult form. There is an inverse relation between the relative length of the internodes of the fibers within a nerve trunk and its resting metabolism. The relative length of the internodes or of the trunk is a direct function of the femur length of the animal. As nerve fibers elongate, they distribute their energy consuming processes more efficiently with the result that there is a lower overall expenditure per unit of weight. If the resting respiration of the axoplasm and membrane is high relative to the supporting elements, these findings suggest that in nerve fibers metabolic processes, like excitatory processes may be confined to the nodes of Ranvier.
Comparative Effects of DL-Thyronine, L-Triiodothyronine and L-Thyroxine on the Isolated Perfused Frog Heart
Authors: Kleinfeld Morris , Rosenthal Albert , Stein Edward
Published: December 2017

Thyronine in dosages between 0.2 and 0.8 mg (7.4 x 10–4m – 3.0 x 10–3m) produced no significant changes in cardiac output, heart rate or electrical potential. Thyroxine in low concentrations (0.2 mg) usually produced a slight increase in heart rate with no change in cardiac output. Triiodothyronine at the same dose increased both parameters. At higher concentrations 0.6 mg (approx. 7.7 x 10–4m) and above, both of the latter agents decreased the heart rate and cardiac output, and produced variable degrees of heart block, arrhythmias and occasionally electrical alternans. There were minimal effects on the P wave. The R wave was usually decreased, the S-T segment was depressed and the T wave became increasingly inverted. The changes caused by triiodothyronine occurred earlier and were also more pronounced. In contrast the absence of any changes following administration of thyronine suggests that different effects on myocardial function can be attributed to the introduction of iodine atoms into the thyronine nucleus.
Effect of Hemorrhage on Red Cell and Plasma Volume of Various Organs of the Dog
Authors: Dunn J. R. , Deavers S. , Huggins R. A. , Smith E. L.
Published: December 2017

Dogs were anesthetized with a morphine-pentobarbital combination. Red cell volumes were measured by radioactive Cr51 and plasma volumes with radioactive I131. The dogs were killed by bleeding and the organs were digested. Aliquot samples of the organs were counted. Twenty minutes after a hemorrhage averaging 46% of the initial blood volume, 7.0 cc/kg of fluid with a mean protein content of 3.2 gm/100 cc entered the circulation. There were 6.7 cc/kg of fluid lost from the organs with 67% of the total coming from the stomach, intestine and skin. After the hemorrhage 2.4 cc/kg of red cells were trapped according to the blood volume calculations, but the cells were not recovered from the organs. The control dogs had 14.1 cc/kg of residual (‘extra’) plasma and after hemorrhage 7.3 cc/kg from the blood volume calculations. Calculation of residual plasma from the organ data agreed well (control 13.8 cc/kg and after hemorrhage 6.1 cc/kg) with the blood volume calculations. Residual plasma remained essentially the same percentage of the blood volume in control and bled dogs.
Effect of Intravenous Blood Thromboplastin Intermediates on Clotting in Rats
Authors: Spaet Theodore H. , Kropatkin Mona
Published: December 2017

Rats were given intravenous injections of blood thromboplastin intermediates. Fully formed blood thromboplastin and product II of Bergsagel and Hougie produced the defibrination syndrome, whereas thromboplastin generation reagents singly or in combination were tolerated without adverse sympatomatic or coagulation effects. In the latter case, there was no evident elevation of blood anticoagulant activity. It is concluded that protection against the intravenous introduction of potential coagulants exceeds that to be accounted for by circulating anticoagulants. A cellular mechanism is hypothesized which clears circulating blood of potential coagulant activity.
Warmth Discrimination in the Dog After a Hypothalamic Ablation
Authors: Murgatroyd Dorothy , Keller Allen D. , Hardy James D.
Published: December 2017

Dogs with impaired heat regulation had a definitely raised thermal threshold; they were able to discriminate the sensation of warmth only at high levels of stimulus intensity. The 75% correct choice threshold for the normal dog varied from about 1.6 to 13.6 millicalories per square centimeter per second (mc/cm2/sec.). The 75% correct choice threshold for the dogs with hypothalamic ablations trained under identical discrimination conditions varied from 46.2 to 72.6 mc/cm2/sec. Since the learning ability of the operated dogs was also found to be impaired, it is not possible to state whether the raised threshold was due to sensory impairment, learning impairment, or a combination of both. Serial sections of the operated brains revealed that damage was localized to the hypothalamus in one animal. Therefore, it is suggested that damage to the hypothalamus per se accounts for the ‘functional’ high thermal threshold rather than involvement of other neurological structures.
Effect of Sodium, Chloride and Potassium Supplementation, With and Without Diamox, on Muscle Composition and Renal Electrolyte Excretion in Electrolyte-Depleted Rats
Authors: Muntwyler Edward , Griffin Grace E. , Iacobellis Michael
Published: December 2017

Electrolytes were determined on plasma, muscle and urine of Na, K and Cl triple-depleted rats following administration for 5 days of equimolar quantities of various electrolyte solutions (NaCl, NaHCO3, KCl, KHCO3 and NH4Cl) with and without Diamox. An attempt was made to relate changes of the plasma HCO3 concentration to an exchange of H+ between extracellular and intracellular fluids and to renal anion and cation excretion. Dietary restriction of Na, K and Cl for 35 days led to a slightly increased plasma HCO3. Supplementation with Na salts caused a striking increase in plasma HCO3, with KCl a slight fall, with KHCO3 a slight rise, and with NH4Cl a marked decrease. In the majority of experiments the altered plasma HCO3 could not be predicted from the H+ exchange, based on relative changes of muscle Na and K. However, in general, it could be predicted on the basis of the relative changes in plasma Cl and Na, which in turn seem to be related to urinary anion and cation excretion.
Cardiac Hypertrophy in Rats and Mice Given 3, 3', 5-Triiodo-L-Thyronine Orally
Authors: Gemmill Chalmers L.
Published: December 2017

The giving of 3,3',5-triiodo-l-thyronine in the drinking water produces marked metabolic and circulatory changes. These effects produce hypertrophy of the heart. The water content of the hypertrophied hearts does not change. The hypertrophy of the heart is obtained in both rats and mice. In the rat, following removal of the T-3, there is a return of the heart to approximately the normal size.
Pineal Blood Content and Its Experimental Modification
Authors: Quay W. B.
Published: December 2017

The blood content of over one thousand rat pineals in various physiological and pharmacological states was determined from acid hematein-stained sections in which the number of erythrocytes per cubic millimeter of pineal tissue was calculated. The lowest mean blood content appears in normal animals between 3 and 5 weeks of age, but castration and administration of estradiol fail to produce significant effects in either sex. Significant pineal vasodilation is produced by injection of adenosine or picrotoxin and by ether anesthesia. No significant vasoconstriction was ever observed, but noradrenaline even in small doses inhibits the vasodilation during ether anesthesia. The blood content of the pineal cortex varies from 1.2 to 2.0 times that of the medulla and the net differences in the two areas after various treatments are generally the same. The blood content of the rat pineal is usually about one-fifth that of the anterior lobe of the hypophysis and one-third that of the posterior lobe.
Hemostasis in Dogs With Heart-Lung By-Pass Circulation
Authors: Cruz W. O. , Oliveira A. C. , Meis L.
Published: December 2017

Heart-lung by-pass circulation obtained in dogs by an apparatus improvised in the laboratory has shown that from the very beginning of the circulation outside the lung the bleeding time increased greatly. The return to normal circulation in the animal after the experiment showed that the hemostasis returns to its normal figure from 30 to 60 minutes afterwards. This observation agrees with prior observations on the different behavior of venous and arterial blood as far as its capacity for hemostasis is concerned, and is in accordance with the increased hemostatic capacity of blood once passed through a heart-lung preparation—all these facts indicating the existence of a lung function in the control of ordinary hemostasis.
Response of Estimated Hepatic Blood Flow to Graded Hemorrhage and the Infusion of Levarterenol
Authors: Gilmore J. P.
Published: December 2017

Levarterenol did not significantly affect the estimated hepatic blood flow, arterial-hepatic venous oxygen difference, or splanchnic oxygen consumption of the dog during graded hemorrhage. During the later stage of hemorrhage hepatic blood flow tended to spontaneously increase so that the percentage reduction in hepatic blood flow was less than the percentage reduction in blood volume.
Leucocyte Agglutinating Systems
Authors: Hartman John D. , Gordon William F.
Published: December 2017

An alteration of leucocyte adhesiveness, as evidenced by agglutination, endothelial sticking, or leucopenia, is associated with a variety of phenomena such as local tissue injury, bacteremia, hypersensitivity reactions, Shwartzman phenomenon and certain types of agranulocytosis. Because such changes in leucocyte dispersion may reflect basic mechanisms fundamental to these phenomena, leucocyte agglutinating systems were studied by a technique for quantitating leucocyte agglutination in vitro. The techniques for inducing leucocyte agglutination involved the nonspecific agglutination resulting when blood is incubated, inflammation and the exposure of the cells to foreign protein in both a sensitive and nonsensitive system. The nonspecific agglutination and the agglutination from inflammation are inhibited by hydrocortisone. That resulting from foreign protein is not. Heparin at high concentrations inhibits the agglutination induced by each of the experimental leucocyte agglutinating stimuli studied. It is postulated that there are at least two leucocyte agglutinating systems as defined by their sensitivity to hydrocortisone and that both systems act through a final common pathway which is inhibited by heparin.
Effect of Feeding Protein and Urea on Renal Concentrating Ability in the Rat
Authors: Hendrikx Achiel , Epstein Franklin H.
Published: December 2017

Maximum urinary concentration, achieved after dehydration or after administration of vasopressin, was significantly higher in rats prefed for 3 days on a 40% protein diet, or a 10% protein, 10% urea diet, than in the same rats fed an isocaloric diet containing 10% protein. The effect of protein in enhancing renal concentrating ability was slightly but significantly greater than that of an isonitrogenous quantity of urea. The solute concentration of urine excreted after large amounts of exogenous vasopressin was not as high as that reached after dehydration alone.
Excitability of the Normally Beating Heart
Authors: Maaske Clarence A. , Bromberger-Barnea Baruch
Published: December 2017

The electrical and mechanical responses to single square wave stimuli applied to spontaneously beating hearts in situ were examined. Shocks were delivered through a time delay circuit triggered by the voltage of the R wave of the ECG. The silver-silver chloride electrodes were 3 mm apart and their position on the ventricular surface kept constant throughout an experiment Stimuli were separated by 20–30 heart beats. The plotted excitability curve (strength-interval) was found to be smooth without any indication of transient variations in threshold. Single stimuli of various durations (up to 100 msec.) and amplitudes (up to 25 ma) were ineffective for the production of ventricular fibrillation. Apparently excitability recovery for a small and localized myocardial area is synchronous and smooth.
Use of Intravascular Carbon Dioxide Gas to Demonstrate Interatrial Septal Defects
Authors: Winters William , Wilson Michael , Chungcharoen Dithi , Stauffer Herbert M. , Durant Thomas M. , Oppenheimer M. J.
Published: December 2017

Carbon dioxide gas injected intravenously will safely demonstrate experimental interatrial defects using a cinefluorographic technique. Under these experimental conditions gas may be demonstrated in the left atrium and ventricle. At the time gas passes through the defect the systemic pressure rises. In the absence of a defect the systemic pressure falls. Left ventricular systolic pressure levels parallel the changes in systemic blood pressure. The presence of gas in the right atrium elevates pressure in the left atrium only a few millimeters of mercury in controls and in the presence of interatrial defects.
Tissue Glycogen Synthesis in Adrenalectomized Rats Fed Glycine-Containing Diets and Given Hydrocortisone
Authors: Todd W. R. , Allen Marilouise
Published: December 2017

Adrenalectomized rats were fed diets with or without added glycine for 36 hours; 4 hours later they were made to swim in 14°C water (the stress). Liver and muscle glycogen determinations at this time showed the levels to be essentially the same in the two groups of rats. When 1 mg of hydrocortisone per 100 gm body weight was given twice a day for 2 days prior to the stress, the glycine-fed animals showed nearly twice as much liver glycogen as the animals prefed the control diet. Muscle glycogen concentrations were not different. Adrenal hormone, glycine and stress are required to demonstrate the ‘protein effect’ of glycine. It now appears, however, that increased adrenal hormone is not a prerequisite.
Effect of Diethylstilbestrol on Utilization of Energy by the Growing Chick
Authors: Hill F. W. , Carew L. B. , van Tienhoven A.
Published: December 2017

Increased fat production in diethylstilbestrol-treated chicks was found to be due primarily to increased energy consumption and to a lesser extent to preferential synthesis of fat at the expense of protein tissue. This was shown in experiments comparing normal and estrogen-treated male chicks with respect to gains in live weight, fat and protein at two planes of nutrition, and the yield of metabolizable and productive (net) energy which they obtained from the diet. It was found that the fattening effect could not be due to increased digestibility, increased net energy yield from absorbed nutrients, or lowered heat production. Under the influence of estrogen, total tissue gain expressed in Calories was increased, and was composed of greater fat gain and lower protein gain. Tissue energy gains were a linear function of metabolizable energy consumption. This relationship predicted equal tissue energy gains under pair-feeding conditions, which was confirmed experimentally.
CO2 Output of Mice Measured by D2O18 Under Conditions of Isotope Re-entry Into the Body
Authors: McClintock Ruth , Lifson Nathan
Published: December 2017

The fractional turnover rates of the hydrogen and oxygen of the body water of mice were measured in three ways: a) by material intake, b) by material output and c) isotopically. Discrepancies occurred between the intake and output turnover rates which could be explained at least in large part by body weight changes. The isotopic turnover rates were lower than those calculated from material output. This finding is discussed in relationship to the diarrhea which the animals developed on the milk diet employed and to the circumstance that opportunity was present for isotope re-entry from excreta. The difference between the turnover rates of the oxygen and hydrogen of the body water was practically the same whether obtained isotopically or calculated from the material balance data. This probably explains the observation that the D2O18 method for calculating the total CO2 output of the mice from the difference between the isotope turnover rates gave valid results in animals in which the absolute values for the isotopic turnover rates were presumably in error.
Alterations of Protein, Lipid and Polysaccharide Composition of Canine Aortas Induced by Allylamine, Gonadal Steroids and Castration
Authors: Norcia L. N. , Gonzalez I. E. , Shetlar M. R. , Peter Jo Anna , Furman R. H.
Published: December 2017

The aortic concentration of cholesterol, phospholipid, alkali-soluble nitrogen and polysaccharides decreased from arch to trifurcation in normal, allylamine-treated, and steroid-treated castrate dogs; total and alkali-insoluble nitrogen increased. These concentration gradients did not correlate with tissue cell counts or potassium levels. Aortic cholesterol increased significantly with age in males but not females. Acetal phosphatide was clearly demonstrated histochemically and its concentration followed the lipid phosphorus gradient. It was noted in juxtaposition to elastic fibers. Other lipids were mostly intracellular. Higher concentrations of cholesterol and alkali-soluble nitrogen existed in the aortas of allylamine-treated dogs and steroid-treated castrate dogs. In addition, slight increases in hexosamine and slight decreases in glycogen were shown in the aortas of allylamine-treated animals. An accumulation of periodic-acid-Schiff positive material other than glycogen was noted at the site of allylamine-induced injury. Allylamine administration increased serum glycoprotein and seromucoid.
Schiff-Sherrington Phenomenon in an Autonomic Reflex
Authors: Wang G. H.
Published: December 2017

Severance of the spinal cord at the tenth thoracic vertebra in cats, not anesthetized but under bulbocapnine, decreases the amplitude of the galvanic skin reflex from the forefeet, in response to an auditory stimulus just as it reduces the intensity of the ipsilateral flexion reflex of the forelegs.
Effect of cortisone and desoxycorticosterone on distribution of radioactive potassium in the adrenalectomized rat
Authors: Hepps S. A. , Hartman F. A. , Brownell K. A.
Published: December 2017

Earlier work has shown that adrenalectomized animals can be kept in good condition with normal plasma K by an adrenal fraction which does not maintain a plasma Na concentration above that characteristic of adrenal insufficiency. Cortisone, which is one of the least effective Na retainers, has been used to study its influence on the uptake of injected K42 in the adrenalectomized rat. In doses of 5 mg/day cortisone corrected the deficient uptake of K42 by tissues of adrenalectomized rats so that they behaved normally except that the uptake was slow. Whether or not physiological amounts of cortisone would do this was not determined. DCA had little influence on K42 movement under our conditions.
Iron-59 metabolism as an index of erythropoietic damage and recovery in monkeys exposed to nuclear radiations
Authors: Hartwig Quentin L. , Melville George S. , Leffingwell Thomas P. , Young Robert J.
Published: December 2017

Monkeys exposed to ionizing nuclear radiations were studied for changes in radio-iron utilization by erythrogenic tissues. Twenty-eight hours after exposure, Fe59Cl3 was injected; twenty-four hours later the first blood sample was drawn. Iron incorporation by the irradiated animals indicated marked erythropoietic depression. At 52 hours after exposure, average uptake in irradiated animals was 2.1% as compared to 10.7% in the controls. Only 3 of the original 10 irradiates survived. On repeating iron-59 injection in supplemented groups of survivors 34 days after exposure, repair and active erythropoiesis were indicated. Plasma iron exhibited periods of both hyper- and hypoferremia. Those animals which died were consistently hypoferremic for 2–3 days prior to death.
Adrenal blood flow in the albino rat
Authors: Sapirstein Leo A. , Goldman Harold
Published: December 2017

The cardiac output fractionation technique employing Rb86 or iodoantipyrine (I131) has been applied to the study of adrenal blood flow in the rat. Either indicator is suitable for the measurement of adrenal blood flow: this is indicated by constancy of label uptake during the first 30 seconds after its administration in a single intravenous injection; when given together the same fraction of each indicator is taken up by the gland. The adrenal flow fraction is 0.14% of the cardiac output in 200–275-gm female rats, corresponding to a flow of 0.078 ml/min. or 1.9 ml/gm/min. The value is increased 114% by ACTH. Ligation of one common carotid artery increases the value 80%. Laparotomy and dissection around the adrenal gland produce irregular changes in adrenal blood flow. The significance of these findings for the ‘normal’ adrenal blood flow is discussed.
Determination of residual blood volume required for survival in rapidly hemorrhaged splenectomized dogs
Authors: Rawson R. A. , Chien Shu , Peng M. T. , Dellenback R. J.
Published: December 2017

Twenty-four splenectomized dogs (average blood volume of 83 ml/kg) were hemorrhaged from 43–55% of their control blood volumes. The Fcells factor as determined from cell (Cr51) and plasma (T-1824) volume measurements was unchanged by severe hemorrhage. (0.88, S.D., 0.020 before and 0.88, S.D., 0.028 after hemorrhage). There were 12 survivors and 12 nonsurvivors. Fifty per cent survival occurred at a residual blood volume of 61%. The results are compared with previous studies in this laboratory and discussed in relation to factors that appear to influence the tolerance to reduction in blood volume.
Plasma volume, cell volume, total blood volume and Fcells factor in the normal and splenectomized Sherman rat
Authors: Wang Louise
Published: December 2017

A method is described for the catheterization of the carotid of the rat which permits blood volume determinations to be made on unanesthetized animals. The cell volume (P32) and plasma volume (T-1824) were measured simultaneously on the day after catheterization. The average Fcells factor was 0.739 (S.D., 0.053) in 11 normal rats and 0.726 (S.D., 0.041) in 10 splenectomized rats. In 50 unanesthetized normal rats the plasma volume averaged 3.90 ml/100 gm body weight. The blood and cell volumes calculated by using the Fcells factor of 0.74 and the separately determined plasma trapping' factor of 0.95 averaged 5.93 ml/ 100 gm and 2.14 ml/100 gm, respectively. These values agree closely with those determined from the simultaneous measurement of cell and plasma volumes and also with the values obtained on 27 normal rats under ether.
Evaluation of variability in the cardiac output of dogs
Authors: Howell Charles D. , Horvath Steven M. , Farrand Enid Allbaugh
Published: December 2017

The cardiac output was calculated by the Fick principle on 245 adult dogs. The mean cardiac output was 2.36, and the range from 0.91 to 5.09 l/min. The cardiac output determined using venous blood from the right auricle was not significantly different from the mean of all determinations. The six groups of dogs, based on different source of arterial and venous blood differed from each other in unpredictable ways, suggesting that the physiological measurements taken between 60 and 90 minutes after anesthesia are subject to great variation, but that cardiac output was no more variable at this time than other physiological measurements made. The cardiac output of these anesthetized dogs was found to have a low correlation with body weight.
Relation between S-T segment elevation and experimental myocardial oxygen gradient
Authors: Zao Zang Z. , Yen Moore , Herrmann George R.
Published: December 2017

Myocardial oxygen gradient was altered variously by means of gas mixture inhalation in acute coronary artery occlusion in dog. This was correlated with the S-T segment elevation in electrocardiograms recorded in a bipolar subepicardial lead across the pink area and cyanotic area of the myocardium. The electrocardiograms revealed a positive relation between them, that is, the S-T segment increased in height with the increasing of oxygen gradient, and decreased in height with the decreasing of gradient. Occasionally there were also observed S-T segment electrical alternans and the merging of the S-T segment. Implications were briefly discussed.
Effect of pulmonary congestion on vagal afferent activity
Authors: Costantin LeRoy L.
Published: December 2017

Pulmonary venous occlusion was shown to increase the activity of slowly-adapting pulmonary stretch receptors by mechanical alterations within the lung parenchyma. Two types of response were evident: a) stimulation throughout the respiratory cycle; b) stimulation only during low lung volumes. Pulmonary arterial occlusion caused both significant increases and decreases in fiber activity. Two fibers demonstrated cardiac-triggered impulses superimposed upon a basic respiratory rhythm, an effect dependent upon pulsation of the pulmonary arterial tree. The results of this investigation indicate a twofold responsiveness of the pulmonary stretch receptors, i.e. to the volume of air in the lungs and, to a lesser extent, to the degree of distention of the pulmonary vasculature. The latter effect is suggested as an important factor in the decreased depth of respiration during pulmonary congestion.
Influence of adrenalectomy on glucose turnover and conversion to CO2: studies with C14 glucose in the dog
Authors: Steele R. , Altszuler N. , Wall J. S. , Dunn A. , de Bodo R. C.
Published: December 2017

In view of the small glucose pool size and turnover rate observed in the untreated hypophysectomized dog and the elevation of these parameters after administration of the 11, 17-oxycorticosteroids, experiments were performed to determine glucose pool size and turnover rate in the unanesthetized adrenalectomized dog in the postabsorptive state. The adrenalectomized dog has a glucose pool of nearly normal size and has a nearly normal rate of glucose flow from the liver into the plasma and from the plasma into the tissue cells. Expiration of C14O2 during the C14 glucose experiments was observed in normal and adrenalectomized dogs and is interpreted on the basis of a three-compartment pool of body bicarbonate as deduced from the C14O2 expiration curve following intravenous injection of HC14O3–. Most adrenalectomized and some normal dogs have a pattern of C14O2 excretion which indicates that glucose upon entering tissue cells either goes promptly to CO2 or is directed into pathways such that its carbon does not become CO2 later on in the course of a 5-hour experiment. The C14O2 data show no clear difference between the normal and the adrenalectomized dog with regard to the conversion of glucose to CO2.
Relationship of pyruvate and lactate during anaerobic metabolism. IV. Local tissue components of total body O2-debt
Authors: Huckabee William E.
Published: December 2017

In anesthetized dogs breathing 10% oxygen, anaerobic metabolic rate (AMR) of the body was measured as the rate of accumulation of ‘excess lactate’ (XL) in ‘mixed venous’ blood and appeared as a smooth, progressively rising curve. However, AMR was very variable in individual regions of the body, varying both with location and with time. The only predictable feature of these patterns was the tendency toward a constant sum. This feature suggested that the irregular distribution of AMR in various local areas was a manifestation of the manner in which the cardiac output was distributed in the body from one time to another, a hypothesis consistent with the theoretical biochemical significance of XL. Lactate exchanges of local tissues did not appear to be related to O2-debt, but the summation of XL exchanges gave a satisfactory approximation of O2-debt. It was concluded that measurements of oxygen, even of oxygen-debt of the body, give no indication of the adequacy of oxygen supply to any individual region of the body, and conversely that study of a local venous blood is unlikely to give an accurate representation of the body as a whole.
Electrolyte balance and enzyme synthesis pattern in rat salivary glands and pancreas
Authors: Schneyer L. H. , Schneyer C. A.
Published: December 2017

Sodium and potassium content and water/dry ratios have been determined for unstimulated and stimulated rat salivary glands and pancreas. Results are correlated with time in the ‘secretion cycle’ of increased amylase synthesis. Increased amylase synthesis by submaxillary and sublingual glands promptly follows the onset of stimulation but is delayed in parotid gland and pancreas by a dependence on gland amylase depletion. Unstimulated submaxillary and sublingual glands from fasted animals have a relatively low Na/K ratio which rises during short-period pilocarpine stimulation, due to loss of K and gain of Na. This increased Na/K ratio is not maintained in these glands during prolonged stimulation but is present during the period of accelerated amylase synthesis. The resting parotid gland has a high Na/K ratio which is reduced during stimulation, due to loss of Na, approximately to the level observed for active submaxillary and sublingual glands. This ratio is maintained during prolonged stimulation of parotid gland. The pancreas presents certain differences from the parotid gland in electrolyte levels, but the patterns of change with stimulation agree generally.
Factors affecting action of acetylcholine on transmembrane flux of K in isolated rabbit atria
Authors: Holland W. C. , Klein R. L. , Briggs A. H.
Published: December 2017

The effects of temperature, cocaine, anoxia, acetylcholine (ACh), K, Na and Ca on influx and efflux of K in isolated rabbit atria have been studied. Increasing the K concentration in the medium (K0) increases both efflux and influx of K; having a much greater effect on the latter. Both fluxes were estimated to be equal at a K0 of 6.0–6.5 mm. ACh increases both influx and efflux. An increase of K0 hardly modifies the effects of ACh in efflux, but greatly enhances its effect on influx. In the presence of ACh both fluxes were estimated to be equal at a K0 of 4.0–4.5 mm. Studies on the influence of temperature, cocaine and anoxia suggest that at K0's less than 5.4 the two fluxes are passive in nature. At K0's above this, influx appears to have an active component. Evidence is presented which suggest that at low K0's ACh affects only passive movements of K, whereas at higher K0's the agent stimulates active transport. A decrease of Na in the medium to one-fifth depresses efflux and influx about 50% when the Ca concentration is maintained at a normal level. A decrease of Ca blocks the effect of low Na. These findings are interpreted to mean that Ca either increases passive movements of K or determines the degree of coupling between Na and K fluxes.
Determination of central blood volume. Comparison of Stewart-Hamilton method with direct measurements in dogs
Authors: Schlant Robert C. , Novack Paul , Kraus William L. , Moore Charles B. , Haynes Florence W. , Dexter Lewis
Published: December 2017

Central blood volume (cardiac output times mean transit time) from right atrium to ascending aorta was determined by the indicator-dilution method in 22 open-chested dogs which had previously had their red blood cells tagged with Cr51. The actual amount of blood in the heart and lungs was calculated from the total radioactivity in the blended homogenate of these organs. The two measurements of central blood volume correlated well ( r = +.88), the indicator-dilution volumes averaging 12% greater. The discrepancy between measurements is probably related to the pulmonary circuit having a lower hematocrit than the large vessels. The results substantiate the use of the Stewart-Hamilton formula (cardiac output times mean transit time) to measure central blood volume.