bluuebunny/crossref_metadata_2025 huggingface dataset:
Possible Central Action of Certain Vasoactive Agents
Authors: Schneider Richard H. , Beck Lloyd , Bohr David F.
Published: December 2017

A previously reported ‘cerebral chemoreceptor buffer mechanism’ was investigated by means of the cross-circulated, vascularly isolated dog head preparation. With the carotid sinuses deactivated, the response of the body blood pressure to centrally circulating vasoactive agents was recorded. When high concentrations of these agents were administered to the isolated head, changes in body blood pressure were frequently observed. However, these changes bore no consistent relation to the blood pressure response of the isolated head or of the intact animal. The body blood pressure response to the central action of these agents was trivial in comparison with the consistent reciprocal response mediated by them through the carotid sinus mechanism.
Activation of Prothrombin With Thrombin
Authors: Fukutake Katsuhiro , Cho Min H. , Seegers Walter H.
Published: December 2017

Mixtures were made consisting of purified prothrombin as substrate (1200 u/ml) and purified thrombin as activator (83 u/ml). The calcium concentration was 0.027 m and the pH 7.2. During an observation time of 90 minutes prothrombin activates and some thrombin is formed. If purified platelet factor 3, or purified platelet cofactor I, or the lipid portion of platelet factor 3, or a certain lipid preparation are also added separately all of the prothrombin substrate becomes thrombin. Each substance is a procoagulant in the sense of functioning in support of thrombin as activator. Each procoagulant is more effective together with Ac-globulin, and even with the latter present sphingosine inhibits the activation of prothrombin by thrombin.
Changing and Constant Temperatures of the Rat as Thermoregulatory Stimuli
Authors: Jacobson F. H.
Published: December 2017

The separate roles of falling, and constant low, body temperature in stimulating the vasomotor and thermogenetic responses of the white rat have been assessed. Peripheral vasoconstriction (indicated by conductance measurements) was induced by constant low body temperature, the degree being a function of the level of temperature. At any temperature, the degree was further increased initially when the temperature began to fall unless heat production was elevated instead. It was decreased initially when the temperature began to rise. Heat production was not significantly correlated with constant body temperature unless ‘corrected’ to normal temperature according to the Q10 law. Heat production was always significantly increased when an already low temperature was caused to decrease further. Oscillations of colon temperature in animals exposed to constant environments have been described.
Gastric Secretion in the Mouse
Authors: Ogawa T. , Necheles H.
Published: December 2017

The basal and stimulated gastric secretion of unanesthetized Holtzman substrain of Rockland RAP white Swiss male mice was investigated. Intubation of the stomach with a plastic tube yielded low values of secretion and acidity due to irritation and mucus production in the stomach. Simple ligation of the pylorus demonstrated that the mouse has a constant basal secretion. Histamine stimulated acid production only when employed in very large doses. Best results were obtained when 0.7 mg of histamine dihydrochloride/gm of body weight (70 mg/kg) was injected subcutaneously. Experiments with ligated pylorus of more than 6-hour duration demonstrated lower acidities, and 24-hour experiments showed no free acid, low total acidity and pH near neutrality.
Synthesis of Tissue Glycogen in Rats Prefed Diets With Added Glycine
Authors: Todd W. R. , Allen Marilouise
Published: December 2017

The maintenance of liver and muscle glycogen after the stress of swimming in cold water, followed by various lengths of recovery periods, has been studied in rats prefed diets with and without added glycine. Rectal temperatures reached a minimum of 33.3°C and returned to normal in about 3 hours in both groups. Though the differences were not great, muscle glycogen was significantly higher in glycine-fed animals at the end of the stress and at all times studied during the recovery period except at 5 hours. Resynthesis started earlier in these animals during recovery. Glycine-fed rats showed markedly higher liver glycogen levels after stress and at all times studied during the recovery period. Redeposition of liver glycogen started earlier in these animals and after 3 hours of recovery the levels had returned to those found immediately following the stress. The control fed rats synthesized much less liver glycogen during the recovery period. The data agree with the postulate that prefeeding diets high in glycine stimulates glycogenesis in rats during an ensuing stress.
Influence of Magnesium Deficiency on Serum Cholesterol Levels in the Rat
Authors: Krehl Willard A. , Barboriak Joseph J.
Published: December 2017

Magnesium-deficient, high-fat and high-carbohydrate diets containing 5 mg magnesium/100 gm were fed to weanling albino rats in order to learn more about the possible relationship between magnesium and lipid metabolism. After 10 weeks of feeding, the blood cholesterol levels of the fat-fed male rats were significantly higher than those fed the carbohydrate diet. The differences between the two female groups were not so pronounced. Serum protein levels decreased in both high-fat and high-carbohydrate-fed animals; the decrease was more evident in the latter groups. Retardation of growth was more pronounced in the groups fed the high-fat diet.
Spinal Synaptic Delay in Young and Aged Rats
Authors: Wayner M. J. , Emmers R.
Published: December 2017

Synaptic delays for the monosynaptic flexor hallucis longus reflex were measured in 117-, 276-, 445- and 822-day-old rats. The mean synaptic delays were 0.97, 1.14, 1.23 and 1.36 msec. Afferent conduction velocity was approximately the same in young (66.1 m/sec.) and old (56.9 m/sec.) rats; however ventral root conduction velocity decreased from 64.2 m/sec. in the young animals to 43.7 m/sec. in the aged rats.
Fluorimetric Measurement of Exogenous and Endogenous Epinephrine and Norepinephrine in Peripheral Blood
Authors: Mangan George F. , Mason John W.
Published: December 2017

The reliability of the Weil-Malherbe and Bone method for the measurement of epinephrine and norepinephrine fluctuations in peripheral blood has been investigated. Epinephrine and norepinephrine injected intravenously (20 µg/kg) produced sharp elevations in appropriate blood levels but disappeared very rapidly, returning to the preinjection range in 2.5–5 minutes. No significant difference was observed in the disappearance rate of epinephrine as compared to norepinephrine. In one animal, evisceration and hepatectomy produced relatively little change in the disappearance pattern, suggesting that peripheral mechanisms, perhaps at adrenergic nerve endings or in skeletal muscle, are involved in removal of these hormones from the circulation. Added epinephrine does not disappear appreciably from plasma in whole blood maintained at body temperature in vitro in time periods comparable to these in the in vivo experiments. Stimulation of the splanchnic nerve in a dog and monkey produced readily detectable changes in both plasma epinephrine and norepinephrine levels with rather characteristic temporal patterns of response for each hormone. It is concluded that the Weil-Malherbe procedure is suitable for further application to investigations of sympathetic nervous system-adrenal medullary function.
Two Processes for Auriculo-Ventricular and Ventriculo-Auricular Propagation of Impulses in the Heart
Authors: Rosenblueth A.
Published: December 2017

In a study of A-V and V-A propagation 61 dogs were used, anesthetized with pentobarbital, with the heart denervated, the adrenals ligated, and the S.A. node crushed. In 15 hearts, unusually long A-V or V-A latencies were recorded. Changes in the stimulus intervals often caused abrupt shortenings to the usual values, or resulted in alternations between the short and long latencies. It is inferred that there exist normally two processes or paths for A-V and V-A propagation. If the rapid process is open, it will be used. But if it becomes blocked, the slow process is still available and allows propagation.
Action of Erythrocyte Extract on the Prothrombin Consumption Test
Authors: Stanski Feliks , Quick Armand J.
Published: December 2017

The prothrombin consumption time for human and rabbit whole blood and for platelet-rich plasma is approximately the same. The addition of an extract of human erythrocytes to the blood or plasma before clotting increases prothrombin consumption significantly except in platelet-poor rabbit plasma. If a mixture of aged normal serum and an extract of erythrocytes is added to the latter, the consumption of prothrombin is greatly increased. This potentiating activity of normal aged serum is also present in aged hemophilic serum, but is diminished in the serum from a patient with hemophilia B (PTC deficiency). The serum factor is destroyed at 60°C and is adsorbed with Ca3(PO4)2. The findings suggest that the cofactor of erythrocytin, the clotting factor in the erythrocyte, may be related to the agent lacking in hemophilia B.
Nature of the Potentiating Substance in Cardiac Muscle
Authors: Whalen William J. , Fishman Noel , Erickson Rudolph
Published: December 2017

An extrasystole, rest, an increase in frequency, or above threshold stimulation with mass electrodes all potentiated the contractions of isolated cat papillary muscle and atrial appendage (but not strips from the posterior wall of the atria). The augmentation diminished or disappeared after the strips had been several days in the bath, after large doses of dibenamine, and after degeneration of the sympathetic nerve supply to the heart. In general, the augmentation phenomena were affected to about the same degree, which suggests a common mechanism. The results are consistent with our working hypothesis that all of the augmentation phenomena are due to intracardiac liberation of norepinephrine during each contraction, possibly from nerve endings. Evidence is presented that acetylcholine is released during activity in the cat papillary muscle as well as in the atria, and that the positive inotropic action of acetylcholine is probably due to the subsequent release of norepinephrine. Acetylcholine is apparently not a requisite for potentiation, however. The relative amounts of norepinephrine and acetylcholine liberated may determine whether augmentation or depression of contractility will be manifested.
Effect of Change in Flow Rate Upon Renal Vascular Resistance
Authors: Haddy F. J. , Scott J. , Fleishman M. , Emanuel D.
Published: December 2017

The effect of changing renal flow rate upon renal vascular resistance has been studied in 82 anesthetized dogs. Resistance decreased and then increased as a function of blood flow rate. The onset of the increase in resistance was more dependent upon flow rate than arterial pressure. These relationships were unaltered by section of renal nerves, infusion of phentolamine, infusion of phentolamine and eserine and ventilation with 20% CO2. The increase in resistance remained following decapsulation but began at lower levels of flow rate and pressure. The increase in resistance was absent during perfusion with blood when dextran was intermittently used as the perfusate, during perfusion with dextran in live or dead kidneys and during perfusion with blood in dead kidneys. Elevation of arterial pressure failed to greatly elevate the flow rate of renal lymph. These observations indicate that the increase in resistance results from active vasoconstriction initiated by some local mechanism which is independent of nerves, circulating adrenalines, CO2 tension and [H+]. The mechanism likely is activated by change in flow rate.
Ventilatory Responses During Muscular Activity in Normal, Thyroidectomized and Thyroxinized Rats
Authors: Kao Frederick F. , Schlig Barbara B.
Published: December 2017

Ventilation and oxygen consumption of Wistar albino rats under pentobarbital sodium anesthesia were determined by means of a microspirometer at rest and during induced muscular exercise employing a 60-cycle alternating current modulated sinusoidally. The study was carried out in untreated, thyroidectomized and thyroxinized rats. The resting ventilatory equivalent for oxygen (VEo2) were 21.53 ± 1.25 (mean ± S.E.), 15.42 ± 1.22 and 27.61 ± 1.62, respectively, and were significantly different from one another. The relationship between ventilation (V, ml/min. BTPS) and oxygen consumption (O2, ml/min. STPD) in these three groups both at rest and during the steady state of exercise was as follows: in normal rats, V = 18.37 O2 + 24.64; in thyroidectomized rats, V = 19.52 O2 – 4.49, and in thyroxinized rats, V = 29.96 O2 – 2.1. The slopes of these fitted lines were revealed to be different in position, with that of normal rats placed between that of thyroxinized rats (highest) and that of thyroidectomized rats (lowest). In addition, the line for the thyroxinized rats has a higher slope than the others, which signifies that the rate of change in ventilation as a function of oxygen consumption is greater.
Exchange of Electrolytes in Smooth Muscle
Authors: Bozler Emil , Calvin M. E. , Watson D. W.
Published: December 2017

Exchange of electrolytes, particularly that of potassium, was studied in the smooth muscle of the frog's stomach by chemical analysis and by following the release of K42 from muscles previously equilibrated with tracer. The muscles exchanged about 4% of their potassium rapidly. After about 20 minutes the washout curves became exponential. Muscles previously washed in 2 mm CaCl2 for 1 hour were able to retain about 80% of the potassium normally present, although the fibers were freely permeable to sodium and potassium. Exchange of potassium in such muscles was slowed by the presence of low concentrations of calcium. The results suggest that the slowness of exchange is not due to a surface membrane, but due to adsorption of a large part of the intracellular potassium.
Critical Role of Arterial Pressure During Hemorrhage in the Dog on Release of Fluid Into the Circulation and Trapping of Red Cells
Authors: Deavers S. , Smith E. L. , Huggins R. A.
Published: December 2017

Experiments were designed to find the volume of blood loss or arterial pressure necessary to produce a significant difference between the measured and expected cell and plasma volume after hemorrhage and following reinfusion. Anesthetized dogs were divided into three groups: The first group was bled a mean of 16% of the original blood volume; the second and third groups were bled to 50 mm Hg (mean bleeding volume of 26%) and 35 mm Hg (mean bleeding volume of 49%) arterial pressure respectively. Red cell volume was measured using radioactive Cr51 and plasma volume with radioactive I131. There was agreement between the expected and measured cell and plasma volume in dogs bled 16 and 26% (held at 50 mm Hg pressure) of their initial blood volume and after reinfusion of the blood. However, the standard error for the 26% group was large. The measured and expected cell and plasma volume of dogs bled 49% (held at 35 mm Hg pressure) of their initial blood volume was not in agreement either after the hemorrhage or reinfusion. A blood pressure of 50 mm Hg appears to be a critical pressure for the operation of the compensatory mechanisms involved in the release of fluid into the circulation, and for the trapping of red cells.
Effect of Pentobarbital Sodium on Uptake of PAH by Rat Kidney Cortex Slices in Vitro
Authors: Støren E. J.
Published: December 2017

Active uptake of PAH by rat renal cortex slices was studied by the method of Cross and Taggart. Uptake was determined at low and at high medium concentrations of PAH. Pentobarbital sodium in concentrations comparable to those found in plasma during anesthesia, significantly depressed the uptake of PAH on all occasions. Simultaneously oxygen consumption was reduced. Acetate failed to stimulate PAH uptake in the presence of pentobarbital, although tissue respiration was restored to normal.
Phosphaturesis: a Direct Renal Effect of Triiodothyronine
Authors: Beisel William R. , Zerzan Charles J. , Rubini Milton E. , Blythe William B.
Published: December 2017

A possible direct renal effect of thyroid hormone was investigated by administering 1.0 mg 3,5,3' l-triiodothyronine (T3) to normal dogs, and measuring the excretion of calcium, phosphorus, magnesium, creatinine and nitrogen for 4 1/2 hours thereafter. In contrast to controls, a pronounced rise in urinary phosphorus regularly followed T3. Renal clearance of phosphorus increased, and tubular reabsorption fell to a mean of 68% of the filtered phosphorus load. A similar response occurred in dogs without parathyroid glands. No increase in calcium, magnesium or nitrogen excretion accompanied the acute phosphaturesis. These results indicate a direct action of triiodothyronine on the renal tubule independent of the level of parathyroid activity.
Effects of Ascites Formation on Response to Rapid Water, Sodium and Dextran Loads in Intact and Diabetes Insipidus Ringer's-Infused Dogs
Authors: Stamler J. , Dreifus L. , Lichton I. J. , Marcus E. , Hasbrouck E. E. , Wong S.
Published: December 2017

The ascitic Ringer's-infused dog exhibits a qualitatively normal diuretic response to rapid intravascular injection of Ringer's solution, glucose-in-water and dextran-in-water. This finding indicates that receptor-effector arcs for sensing and disposing of ingested fluid loads are intact and operative in the ascitic animal, but ordinarily fail of adequate stimulation because of the hemodynamic aberration leading to depletion of effective circulating fluids. The production of gross ascites and fluid retention in the diabetes insipidus dog demonstrates that the hypothalamic-posterior pituitary antidiuretic system is not an essential prerequisite for edema formation.
Changes in Cardiac Contractility During Immersion Hypothermia
Authors: Covino Benjamin G. , Beavers W. R.
Published: December 2017

Cardiac contractility was determined during progressive hypothermia in intact anesthetized dogs by attaching a strain gauge arch directly to the left ventricle. A threefold increase in contractile force was observed as the rectal temperature fell to 25°C. Below this temperature a gradual reduction in amplitude of contraction occurred. Neither a decrease in diastolic interval nor circulating blood volume influenced the augmented contractile force. A similar increase in force of ventricular contraction resulted when the isolated perfused rabbit heart was cooled. The data suggest that cold per se exerts a positive inotropic action on cardiac muscle.
Effect of Artificially Controlled Heart Rate on the Incidence of Ventricular Fibrillation in Hypothermia
Authors: Torres J. C. , Angelakos E. T. , Hegnauer A. H.
Published: December 2017

Five dogs were subjected to auricular and five to ventricular driving throughout the period of cooling. All animals in both groups succumbed to ventricular fibrillation at mean temperatures of 21.3°C and 20.3°C, respectively. These temperatures do not differ significantly from those for dogs with spontaneous heart action. Thus, abnormalities in S-A nodal rhythm or A-V conduction appear not to be contributory to fibrillation, since the one is eliminated by auricular driving and the other by ventricular driving. Intraventricular conduction times were assumed equal to the QRS duration. In both groups the conduction time increased linearly over the temperature range studied, and the slopes were parallel, suggesting that the limiting, temperature-sensitive process in conduction is the same for Purkinje system and myocardium.
Absorption of Cholesterol Esters in the Lymph-Fistula Rat
Authors: Vahouny George V. , Treadwell C. R.
Published: December 2017

Free and esterified cholesterol fractions in thoracic duct lymph of rats were determined after the administration of emulsions containing saline, albumin, taurocholate, oleic acid and free cholesterol, or fatty acid esters of cholesterol. Total lymph cholesterol increased within 3 hours after feeding free cholesterol or the natural cholesterol esters. Cholesterol butyrate was absorbed as well as free cholesterol, while the esters of oleic and linoleic acids, were absorbed slower and less efficiently. Saturated acid esters, laurate and stearate were absorbed slowly and inefficiently. Administration of cholesterol trimethylacetate, which is resistant to the hydrolytic action of pancreatic cholesterol esterase, did not result in any increase in lymph cholesterol above the control level. Throughout all groups in which absorption of cholesterol occurred, the absorbed cholesterol in lymph was esterified from 87% to 95%. The data are in agreement with the concept that dietary cholesterol esters are hydrolyzed in the intestinal lumen prior to absorption of the cholesterol moiety as free cholesterol.
Localization and Characterization of Sodium Transport Along the Renal Tubule
Authors: Malvin Richard L. , Wilde Walter S. , Vander Arthur J. , Sullivan Lawrence P.
Published: December 2017

The proximal tubular Na transport system was investigated using our stop flow analysis. During varying degrees of osmotic diuresis in dogs the ureter of one kidney was occluded for 2 1/2–8 minutes. Following occlusion serial urine samples were collected and analyzed for Na, creatinine, PAH or glucose. Using urinary creatinine concentrations as an index of water movement the mass of Na and water reabsorbed from the proximal segments during occlusion was calculated. In all experiments the calculations showed that the Na concentration in the proximal reabsorbate was of the same concentration which existed in plasma. Such behavior is inconsistent with a proximal Na pump which would otherwise reabsorb a supraplasma-level Na solution away from mannitol and Na in the tubule. The data suggest that Na and water transport out of the proximal tubules may be a passive process initiated by the colloidal osmotic pressure differences which exist between the intratubular urine and the peritubular capillary blood. A passive mechanism for Na and water reabsorption from the proximal segment resolves many difficulties faced by a Na pump.
Effect of Sex, Fasting and Alloxan Diabetes on the Uptake of Neutral Fat by Isolated Perfused Rat Liver
Authors: Heimberg Murray , Meng H. C. , Park C. R.
Published: December 2017

A method is described for measuring the uptake of neutral fat by the perfused rat liver in vitro. The rate of fat uptake by the isolated liver was influenced by the endocrine balance of the animal at the time the organ was removed. Livers from female rats had a significantly greater rate of fat uptake than livers from males. The rate was markedly increased by fasting and by alloxan diabetes. Insulin reduced the fat uptake of the diabetic liver when the hormone was administered to the animal, but was ineffective when added directly to the perfusion fluid. The results suggest that the rate of uptake of neutral fat by the liver is under direct hormonal control.
Sodium and Chloride Spaces and Water Content of Tendon in Normal and Depleted Rats
Authors: Audia Marino
Published: December 2017

In normal rat tail tendon where evaporation is prevented, sodium space is significantly lower than water ( P < 0.001), while chloride space is not significantly different from water ( P = 0.2). On acute sodium and chloride depletion by intraperitoneal dialysis with 4.5% mannitol, the observed changes in sodium or chloride space/water are not significant ( P > 0.05). Rat tail tendon water closely resembles plasma ultrafiltrate with respect to chloride concentration, but its sodium concentration is less than that of an ultrafiltrate.
Effect of High Environmental Humidity on Survival of Mice Following an Experimental Burn
Authors: Pence D. , Lindsey D.
Published: December 2017

In experimental burns in mice, an increase in environmental humidity is not correlated with a decrease in mortality from burn shock, but may be correlated with some increase in mortality.
Effects of Thermal Conditioning on Metabolic Responses of Rats to Altitude
Authors: Mefferd Roy B. , Hale Henry B.
Published: December 2017

The metabolic responses of rats acclimated to different temperatures (3°, 24° and 35°C) were compared during a 24-hour fasting exposure to low barometric pressure (380 mm Hg). Determinations included fasting weight loss, water intake, urine volume and urinary excretion of Na, K, Mg, Ca, PO4, urea, uric acid, creatinine, creatine, taurine, ß-alanine, glycine, α-alanine, valine + methionine, serine, threonine, tyrosine, glutamic acid, aspartic acid, lysine, arginine and histidine. Since the altitude tests were made at a neutral temperature (25°C) the altitude responses, per se, were determined by comparing the ground and altitude responses of each acclimated group at neutral temperatures. These comparisons revealed that the acclimated state of the rats exercised a strong influence on the altitude response for most of the variables. There were significant intergroup differences in this response for all variables except phosphate, urea, taurine, valine + methionine, serine, histidine and the Mg/Ca ratio.
Effect of LSD-25 on Body Temperature of Pigeons
Authors: Hoffman Roger A.
Published: December 2017

The body temperature of pigeons decreases following the subcutaneous administration of LSD-25. This temperature decrease at 1 hour postinjection shows a straight line relationship to the log of the dose between 1 and 250 µg/kg. Maximal response occurs at 1–2 hours and is followed by a rapid but incomplete recovery toward normal by 4–6 hours. Successive daily injections for 2 days show that no refractoriness develops to this compound within this time period. Simultaneously with the temperature response, the oxygen consumption and heart rate decrease while the breathing rate increases greatly. The temperature decrease is due, therefore, to both reduced heat production and increased heat loss.
Early effects of ‘total’ pancreatectomy on fat metabolism in the rat
Authors: Chernick Sidney S. , Scow Robert O.
Published: December 2017

Within 2 hours after ‘total’ pancreatectomy in fasting rats blood concentrations of glucose, ketone bodies and total lipids were significantly elevated. Blood ketone bodies and total lipids increased before the blood glucose reached diabetic levels. The increase in blood lipids was due largely to triglycerides and was accompanied by accumulation of fat in the liver and kidneys. When depleted of body fat prior to surgery, pancreatectomized rats did not develop ketosis, hyperlipemia or fatty liver and kidneys. Repeated injections of insulin started immediately after pancreatectomy prevented development of diabetes. When insulin was given for the first time 1 day after pancreatectomy, blood glucose, ketone bodies and fats were lowered to normal fasting levels within 3 hours; 2 days after pancreatectomy, blood glucose and fats were reduced to normal levels whereas the ketonemia, although somewhat decreased, remained high. The rapid changes in blood ketone bodies are interpreted as evidence of a direct insulin action on liver. The decreased insulin effect on ketonemia in rats deprived of insulin for 2 days may indicate development of hepatic resistance to insulin.
Blood volume, bleeding volume and tolerance to hemorrhage in the splenectomized dog
Authors: Allen Thomas H. , Walzer Richard A. , Gregersen Kirsten , Gregersen Magnus I.
Published: December 2017

The relation between blood volume reduction and survival was studied in 28 experiments on 20 splenectomized dogs using Walcott's bleed-out and replacement procedure for adjusting the blood volume to the critical range. Plasma volume was measured with T-1824 and blood volume calculated using the Fcells factor of 0.87. Control blood volumes averaged 95 ml/kg in the lean dogs and 78 ml/kg in medium fat dogs. However, the bleeding percentage (bleeding volume as percentage of blood volume) was nearly the same in both groups with an over-all average of 57%. Fifty per cent survival was computed to occur at 66% of the initial blood volume, the critical range extending from 62 to 74%. The volume of fluid replaced by compensatory dilution averaged 10% of the control blood volume.
Cell volume, plasma volume, total blood volume and Fcells factor in the rhesus monkey
Authors: Gregersen Magnus I. , Sear H. , Rawson R. A. , Chien Shu , Saiger G. L.
Published: December 2017

Forty-two simultaneous measurements of plasma and cell volume with T-1824 and P32 were made on 18 normal monkeys ranging in weight from 3.4 to 7.1 kg. Nine determinations were made on two animals at varying intervals during a 16-month period. The mean values and standard deviations were as follows: cell volume 17.7 (S.D., 1.66) ml/kg; plasma volume, 36.4 (S.D., 3.98) ml/kg; blood volume, 54.0 (S.D., 4.72) ml/kg; Fcells factor, 0.83, (S.D., 0.046); venous cell percentage (hematocrit value x.96), 39.6; plasma protein (refractometer) 7.26 gm %. Variations among animals in plasma and blood volume, expressed in milliliters per kilogram were significantly greater than those observed in the same animal during the 16-month period.
Autonomic vasomotor responses in the canine hepatic arterial and venous beds
Authors: Green Harold D. , Hall Locksley S. , Sexton James , Deal C. P.
Published: December 2017

Blood flows (electromagnetic flowmeter) and pressures were recorded simultaneously in the hepatic artery and portal vein during left splanchnic nerve stimulation, and during injections of adrenergic substances and of methacholine into the hepatic artery and into the portal vein, before and during progressively increasing adrenergic blockade induced by Ilidar or Dibenzyline injected into the hepatic artery and into the portal vein. During the cannulation procedure it was observed that temporary occlusion of the portal vein caused a much greater fall of arterial pressure than did occlusion of the splenic vein. Intra-arterial and intravenous injections of arterenol, and splanchnic nerve stimulation all had qualitatively similar effects. All caused constriction as indicated by an increase in resistance to flow in both the hepatic arterial and portal venous vascular beds. Epinephrine was slightly more potent than either of the other stimuli and the hepatic artery bed was slightly more responsive to the adrenergic substances than was the portal venous bed. Adrenergic blockade progressively abolished the constrictor responses in both beds to epinephrine, arterenol and sympathetic nerve stimulation without inducing significant reversal. No sympathetic, adrenergic (isoproterenol), or cholinergic dilator responses were observed in either hepatic bed. These results are in contrast to those of the mesenteric artery bed which gave dilator responses to isoproterenol, and to epinephrine during partial adrenergic blockade. Both hepatic beds gave less marked vasoconstrictor responses to the adrenergic substances and to splanchnic stimulation than did the previously reported mesenteric artery bed.
Plasma 17-hydroxycorticosteroid levels during electrical stimulation of the amygdaloid complex in conscious monkeys
Authors: Mason John W.
Published: December 2017

Substantial plasma 17-OH-CS elevations invariably occurred during electrical stimulation of the amygdaloid complex in unanesthetized rhesus monkeys through chronically implanted electrodes. No evidence of localization of this effect within anatomical subdivisions of the amygdaloid complex was observed. Stimulation of the amygdala elicited plasma 17-OH-CS elevations (20 µg %/hr.) equal to those occurring with hypothalamic stimulation or injection of a large dose of ACTH (16 mg/kg), while no elevations were observed during putamen stimulation or under normal conditions.
Comparison of total body and tissue losses of sodium and chloride with losses from sucrose space in salt-depleted rats
Authors: White H. L. , Audia M. , Rolf Doris
Published: December 2017

When about 30% of total body Na and Cl is removed from normal adult rats by intraperitoneal dialysis, the external loss of Na and Cl measured 24 hours later is adequately accounted for by loss from ECF (sucrose space). Only small amounts of Na and Cl enter ECF from gastrointestinal contents and bone. Conclusions drawn from muscle and skin samples agree with that from whole body. Such depleted animals remain almost in water balance. Evidence is presented that sucrose space is an equally valid measure of ECF in normal and in depleted animals.
Response of bone sodium to acute changes in extracellular fluid composition (cat)
Authors: Forbes Gilbert B. , Tobin Richard B. , Lewis Anne
Published: December 2017

A study has been made of the effects of short term infusions of various acids, alkalies, NaCl and glucose solutions on bone sodium content in the cat. Bone water was unaffected by any of the procedures used. A decline in bone sodium, expressed as Na/Ca ratio, of 3.5–8.0% was observed in the various treatment groups. This is 15–100% of the exchangeable fraction. The magnitude of the decline in Na content was found to be independent of changes in blood pH, plasma Na concentration, and total ECF Na content, and the amount of acid or water infused. Sodium loading did not cause a rise in bone Na content. The nature of the stimulus or stimuli responsible for the observed change in bone Na is not apparent from these experiments.
Complete solution of the three-compartment model in steady state after single injection of radioactive tracer
Authors: Skinner S. M. , Clark R. E. , Baker N. , Shipley R. A.
Published: December 2017

Solutions of a general, three-compartment model in a nonisotopic steady state are developed. By means of these solutions, the investigator may analyze a great variety of kinetic flow relationships utilizing only algebraic procedures. Values of compartment sizes, rates of transport and specific activity-time curves are obtained for three typical hypothetical examples. Possible degrees of freedom and the use of parameters are examined. For those models where physical limitations prevent sufficient independent observations to allow completely determinate solutions, possible limiting values are established.
Glycogenolytic action of mercaptoethylamine
Authors: Sokal Joseph E. , Sarcione Edward J. , Gerszi Kornel E.
Published: December 2017

The observation of Bacq, Herve and Fischer ( Bull. acad. roy. méd. Belg. 18: 226, 1953), that mercaptoethylamine induces depletion of liver glycogen in rats and mice, has been confirmed. The disulfide form of the drug (cystamine) is more consistent in its action than the sulfhydryl form (cysteamine). Parenteral doses of 150 mg/kg induce 70– 90% depletion of liver glycogen of fed rats in 2–3 hours. Intragastric administration is also effective, but higher doses are required. The compound is effective in adrenodemedullated and in depancreatized rats, and may, therefore, act directly on the liver. Reduction of muscle glycogen was observed in normal and depancreatized, but not in adrenodemedullated, rats. In adrenodemedullated rats, but not in normal or depancreatized rats, mercaptoethylamine induced distinct declines in blood glucose, in spite of hepatic glycogenolysis. These findings suggest that this agent stimulates the secretion of epinephrine and of insulin.
Cerebral and cerebellar afterdischarges in the cat
Authors: Gualtierotti Torquato
Published: December 2017

Single pulse stimulation of the lateral geniculate body and other optic centers in the brain stem, in addition to evoking potentials in the visual area, induced a widespread afterdischarge on the cortical surface of the brain of the cat. This discharge consists of a number of 7–13/sec. surface-positive waves. It starts from an extravisual trigger area and spreads intracortically at a speed of 0.5 mm/sec. Extracortically an afterdischarge made up of waves at half the frequency of the cortical afterdischarge was recorded from the deep nuclei of the cerebellum and from the inferior olive. This activity is induced by the cortical afterdischarges. No change occurred in pyramidal tracts activity during the afterdischarges. Sensory evoked potentials and afterdischarges did not interfere with one another. The afterdischarge did not alter the gross behavior of the animal.
Effect of anesthetic agents on spinal cord of cat
Authors: Randt Clark T. , Collins William F.
Published: December 2017

Somatic evoked responses in the dorsal column and anterolateral column of the cervical spinal cord in 14 cats are shown to have differential susceptibility to anesthetic agents. Nitrous oxide, cyclopropane and Nembutal have more effect on the postsynaptic anterolateral column potentials than on the larger fiber presynaptic dorsal column or postsynaptic medial lemniscus responses. The results corroborate the previous evidence indicating greater susceptibility of small fiber afferent systems to anesthetic agents.
Absorption of lipid following thoracic duct ligation in the rat
Authors: Annegers John H.
Published: December 2017

Dietary intake and fecal excretion of lipid were measured during 3-day periods before and after thoracic duct ligation in rats. Also, the quantity of lipid recoverable from the intestine 6 and 18 hours after olive oil or oleic acid had been placed in the duodenum was determined in control and thoracic duct-ligated rats. No change in lipid absorption attributable to duct ligation was demonstrated in either type of experiment.
Dissociation of the calcium-protein complex of laying hen's plasma
Authors: Winget Charles M. , Smith Arthur H.
Published: December 2017

The bound, or nondiffusible, calcium component of laying hen's plasma was found to be freely dissociable, in conformance with the mass action principle. No evidence of enzymatic activity, which would dissociate the complex, was found in various tissues and materials associated with shell formation. The kinetics of dissociation of the calcium-protein complex were studied in a series of plasma preparations in which the calcium concentration alone was varied. The dissociation constant for the calcium-protein complex of laying hen's plasma was found to be 10–1.1. Also investigated was the effect of changes in salt concentration (NaCl) and pH on the dissociation of calcium-proteinate.
Circulating and tissue hematocrits of normal unanesthetized mice
Authors: Friedman Julius J.
Published: December 2017

The circulating and tissue hematocrits of normal unanesthetized mice were determined by means of independent red cell and plasma volume measurements. The red cell volume-indicator which was used in this study was radioiron (Fe59) tagged red cells. The plasma volume data were derived by means of radioiodine (I131) labeled serum albumin and were reported earlier (Friedman, Proc. Soc. Exper. Biol. & Med. 88: 323, 1955). The hematocrits of the various tissues were found to be: for spleen 51.3, lung 47.9, muscle 49.9, liver 38.9, intestine, 32.2, skin 29.2 and kidney 24.0%. The total body hematocrit was 35.4% as compared to 48.4 for venous blood. All tissues, with the exception of spleen and lung, contained hematocrits which were lower than that of venous blood suggesting the presence of some mechanism within the various tissues which is capable of effectively separating plasma from red cells.
Serum transaminase and alkaline phosphatase levels after large doses of norepinephrine and epinephrine in dogs
Authors: Highman Benjamin , Maling Harriet M. , Thompson Edwin C.
Published: December 2017

An intravenous infusion in conscious dogs of a large dose of norepinephrine (0.51–0.85 mg/kg) or epinephrine (0.55–0.92 mg/kg) resulted in an elevation in serum glutamic oxalacetic transaminase (SGO-T) which reached a peak in about 6 hours and subsided within 2–3 days. Serum glutamic pyruvic transaminase (SGP-T) and serum alkaline phosphatase increased more gradually and subsided more slowly. Pathologic studies confirmed the myocardial and hepatic damage suggested by the elevated serum enzyme levels. Subcutaneous injection of 1 mg/kg epinephrine-in-oil produced less severe pathologic changes, but resulted in a gradual increase during the first day in SGO-T, SGP-T and serum alkaline phosphatase with peak levels considerably higher than those following the intravenous infusions. Markedly elevated serum enzyme levels, suggesting cellular damage with altered permeability, occurred even in animals showing no significant myocardial hypersensitivity and no significant myocardial and hepatic changes demonstrable by the usual histologic methods. The adrenergic blocking agent Dibenzyline prevented the rise in serum transaminases but not the rise in serum alkaline phosphatase.
Prevention of late deaths in X-irradiated mice by injected hematopoietic cells from homologous newborn donors
Authors: Cole Leonard J.
Published: December 2017

Previous studies have shown that the injection of spleen cells from normal adult parental strain (A-strain) mice into sublethally x-irradiated (500 r) F1 hybrid mice ((LxA)F1), elicits delayed deaths in 100% of the animals. This lethal effect is elicited, as shown here, also by spleen cells from adult L-strain mice, but not by spleen cells derived from newborn (1–2-day-old) parental strain mice. Following supralethal whole-body x-irradiation (870 r) of LAF mice, the injection of cells from spleen or liver of newborn A-strain mice afforded up to 100% protection against death by 30 days postirradiation; no late ‘homologous deaths’ were seen in the mice which received spleen cells from the newborn A-mice, in contrast with that observed when hematopoietic cells from adult A-mice are injected. The data imply that spleen cells from newborn mice are immunologically nonreactive, and lend further support to the hypothesis that late homologous deaths (in the context employed here) results primarily from an immunological reaction of the injected cells against the host.
Changes in urine concentration during prolonged administration of vasopressin and water
Authors: Levinsky Norman G. , Davidson Douglas G. , Berliner Robert W.
Published: December 2017

Vasopressin and water were administered to dogs for periods of up to a month. The initial increase in urine osmolality was maintained for only 3–12 days. Thereafter, urine concentration fell to less than half the maximum value and remained at these lower levels indefinitely. The decrease was associated with expansion and dilution of body fluids. It could not be correlated with the rises in filtration rate which occur, nor with the decreased plasma osmolality and sodium per se, nor was it associated with increased solute excretion. A low salt diet alone or with desoxycosterone acetate (DCA) decreased the maximum urine concentration achieved after vasopressin. Adrenalectomy abolished this effect of the low salt diet.
Evaluation of neurogenic and metabolic influences from a perfused leg on respiratory exchanges
Authors: Bailen Harold N. , Horvath Steven M.
Published: December 2017

Paired mongrel dogs of near equal weight were used in two separate series of perfusion experiments. In the first series, the amputated leg of the ‘perfused’ dog remained connected to the rest of the body by the femur and the femoral nerve. The arterial and venous femoral vessels were anastomosed to the corresponding vessels in the ‘donor’ dog. Three milligrams per kilogram of 2–4-dinitrophenol was injected intravenously into the donor dog which was now perfusing the amputated extremity. The expired air was collected, analyzed and subjected to statistical analysis. It was found that the minute volume, oxygen consumption and carbon dioxide production exhibited an increase of approximately 100% above control values in the donor dogs. The perfused animals in this series also exhibited marked increases in the same parameters. It was discovered that dinitrophenol was reaching the perfused animal via the blood supply of the intact femur. Therefore, a second series of experiments was undertaken in which the femur was also amputated leaving the nerves as the sole connection to the body of the animal. The donor dogs again exhibited the expected elevation in ventilatory function, but the perfused animals demonstrated no changes. In both series, severing the nerves did not alter the ventilatory response. The data suggest that increased metabolism per se does not stimulate pulmonary ventilation via neural pathways.
Mechanism of the phosphaturic action of acute intravenous injection of parathyroid extract in the dog
Authors: Foulks James G. , Perry Florence A.
Published: December 2017

In the fasted dog, the acute intravenous injection of parathyroid extract leads to an appreciable augmentation of the urinary excretion of endogenous phosphate only when the renal threshold for phosphate excretion is initially low and only when this procedure is accompanied by a corresponding elevation of the filtered phosphate load. In similar circumstances an increase in the glomerular filtration rate by means of abrupt expansion of the extracellular fluid also elicits phosphaturia. These phosphaturic responses may dwindle in spite of persistent elevation of the filtered phosphate load, the rising threshold for phosphate excretion being associated with apparent cellular phosphate depletion. In the parathyroidectomized dog, the acute intravenous injection of parathyroid extract is followed by a considerable transfer of phosphate out of the extracellular fluid compartment, whether or not a concomitant phosphaturia develops.
Alterations in renal tubular phosphate transport during intravenous infusion of parathyroid extract in the dog
Authors: Foulks James G. , Perry Florence A.
Published: December 2017

The intravenous infusion of parathyriod extract at an adequate rate (1–4 u/kg/hr.) invariably leads to phosphaturia which is primarily the result of altered renal tubular transport of the ion. In the intact fasted dog, several hours may be required for the infusion of parathyroid extract to reduce the initially high threshold for endogenous phosphate excretion below the filtered phosphate load. Other procedures which reduce the threshold for phosphate excretion may accelerate the onset of phosphaturia under these circumstances. However, the sluggish nature of this response suggests that parathyroid hormone does not contribute to the rapid adjustments in renal tubular phosphate transport which accelerate phosphate excretion following phosphate administration.
Recovery from a single dose of X-ray in old and young rats
Authors: Hursh John B. , Casarett George W.
Published: December 2017

Rats received a large single dose of whole body x-ray followed by a test dose at an interval of 2, 5 and 8 days. Mortality in 30 days was measured and recovery from the first dose was calculated. Rats aged 546 days recovered at a rate no less rapid than that of 107-day-old rats. The implication of the recovery data is briefly discussed.
Effect of various stressors on muscular contraction induced by NaH2PO4 and NaClO4
Authors: Selye Hans , Bajusz Eörs
Published: December 2017

Experiments in the rat indicate that the motor disturbances elicited by sudden overdosage with NaH2PO4 and NaClO4 are qualitatively different. NaH2PO4 produces a tetany-like condition, with generalized continuous tremor and occasional fits of generalized clonic convulsions. NaClO4, on the other hand, induces no tremor, but rather persistent, tonic extensor cramps, predominantly in the hind legs. Among a great variety of stressors, only those associated with increased muscular work (exercise in a revolving drum, forced restraint, electric shocks) enhanced the susceptibility to acute NaH2PO4 intoxication, while all the stressors that were examined elicited marked muscular contractions following treatment with threshold doses of NaClO4. These effects of NaH2PO4 and NaClO4 are not due to the Na-ion as such, since equimolecular amounts of NaCl were totally ineffective in producing muscular contractions. It appears that an excess of NaH2PO4 and NaClO4 interferes rather selectively with the biochemical processes responsible for muscular contraction; hence, these salts induce fatigue and muscle dysfunction, following comparatively brief periods of exercise. In addition, the muscular action of NaClO4 (unlike that of NaH2PO4) is greatly enhanced even by stressors which do not act preponderantly upon muscle.