bluuebunny/crossref_metadata_2025 huggingface dataset:
Glomerular filtration in the rat after ureteral ligation
Authors: Salomon Lothar L. , Lanza Frank L.
Published: December 2017

The rate of glomerular filtration in rats with ligated ureters was found to depend on the length of time after establishment of obstruction. About 4% of plasma passing through the kidney was filtered after 30 min of total ligation, compared with nearly 20% in control rats. The rate progressively increased thereafter, exceeding half the control rate within 4 hr, but undergoing no further important changes up to 6 hr after ureteral obstruction. Intravenously administered inulin diminished rapidly in plasma of control rats, less rapidly in rats with ureters ligated 4 hr prior to the injection, and most slowly in nephrectomized rats, the relative concentrations 3 hr after injection being 1:3:8, respectively. Inulin recoveries were essentially complete in all cases. This supports the conclusion that concentration of inulin in plasma at termination of the experiments was inversely and solely related to efficiency of glomerular filtration. The apparent 3-hr inulin space for these special conditions, derived from measurements on nephrectomized rats, was 17.3 ml/100 g total body wt. in rats fasted for 24 hr with free access to water.
Free amino acid and amine concentrations in liver: effects of hydrocortisone and fasting
Authors: Kaplan S. A. , Nagareda Shimizu C. S.
Published: December 2017

Concentrations of the following Ninhydrin-reacting substances (NRS) were determined in the unhydrolyzed protein-free fraction of mouse liver by column chromatography: phosphoethanolamine, taurine, urea, aspartic acid, threonine, serine, glutamine, proline, glutamic acid, glycine, alanine, valine, cystine, methionine, isoleucine, leucine, tyrosine, phenylalanine, ß-alanine, ß-aminoisobutyric acid, α-aminobutyric acid, ornithine, ethanolamine, lysine, histidine, and arginine. The NRS present in highest concentration was taurine. Adrenalectomy, fasting for 24 hr, and cortisol administration had little effect on the sum of NRS or individual amino acids. Administration of cortisol did, however, decrease the concentration of amino acids in fasted adrenalectomized animals but increased their concentration in nonfasted adrenalectomized animals. Since the concentration of amino acids was lowered or raised under circumstances known to increase protein synthesis, it is concluded that increased protein synthesis promoted by cortisol is independent of the total pool of amino acids in liver.
Metabolism of 4-C14-cholesterol in the isolated perfused rat liver
Authors: Danielsson Henry , Insull William , Jordan Paul , Strand Ove
Published: December 2017

The influence of the mode of administration on the distribution and oxidation of 4-C14-cholesterol in the isolated perfused rat liver has been studied. When labeled cholesterol was added to the perfusate as an emulsion with Tween 20 only about 1% of the labeled liver cholesterol was oxidized to bile acids. Approximately the same oxidation (1–2%) was obtained in perfusions of livers from animals injected with emulsions of 4-C14-cholesterol 1 hr before operation. When livers were perfused with blood withdrawn from animals injected with emulsions of 4-C14-cholesterol 24 hr prior to sacrifice the amount of labeled liver cholesterol converted to bile acids was about 10%, i.e., five to ten times more than in the above-mentioned sets of experiments, indicating the advisability of using physiological solutions of cholesterol rather than artificial emulsions. The main labeled acidic products were identified as cholic and chenodeoxycholic acid. The only labeled product isolated from ethanol extracts of the liver was found to be identical with cholesterol.
Secretion of magnesium by dog parotid gland
Authors: Langley L. L. , Grimes O. R. , Cockrell D. F.
Published: December 2017

Prolonged, steady secretion of saliva results in a decrease in magnesium concentration until a steady state is reached after about 40 min. During this period the glandular concentration of magnesium also diminishes. The salivary magnesium concentration increases as the rate of flow decreases. This effect is most marked at flows below about 0.2 ml/min. The amount of magnesium in saliva varies directly with that in plasma. Since over a wide range of magnesium plasma concentrations the saliva/plasma ratio is approximately one, and because no change in concentration occurs during the stop flow procedure, it is suggested that the salivary secretion of magnesium is a passive process. Stop flow studies using Mg28 indicate that the primary site for transport of magnesium from plasma to saliva is in the intralobular ducts. These results are consistent with the hypothesis that electrolytes are transferred from plasma to saliva primarily by activity of the duct cells, that these processes are not coupled, and that they can proceed at varying and independent rates.
Muscarinic synapses in the hypothalamus
Authors: Stein Larry , Seifter Joseph
Published: December 2017

It has been reported that drinking may be selectively induced by direct application of cholinergic crystalline substances (carbachol, acetylcholine capped with physostigmine) into the hypothalamus. We confirmed and extended this finding by demonstrating that this central cholinergic effect was based on a muscarinic, and not a nicotinic, action. Minute quantities (10–20 µg) of crystalline substances were introduced into the brains of 28 water-satiated rats through permanently indwelling cannulas. Muscarine had an effect equal to carbachol; strong drinking was elicited within 5–10 min and persisted with variable intensity for almost an hour. Nicotine had the same small, apparently nonspecific effect as sodium chloride—about twice as much drinking as when under no drug, but only 20% of the effect of carbachol or muscarine. Serotonin, potassium chloride, and sucrose had no measurable effects. The effects of carbachol and muscarine were largely blocked by prior application of atropine into the brain. It was concluded that chemical stimulation of muscarinic receptors in the hypothalamus can elicit drinking.
Extracellular space estimation in rat kidney slices using C14 saccharides and phlorizin
Authors: Rosenberg Leon E. , Downing Sylvia J. , Segal Stanton
Published: December 2017

Estimation of the extracellular fluid space of rat kidney cortex slices with C14-labeled inulin, sucrose, dulcitol, and mannitol suggest that only inulin is confined to an extracellular location in this tissue. The other saccharide molecules studied penetrate tissue cells in kidney slices to a variable degree, and therefore, are not suitable for the estimation of the extracellular compartment. The present studies also indicate that phlorizin inhibits the cellular penetration of sucrose, dulcitol, and mannitol, and thus may be useful in determining whether a given sugar molecule is or is not limited to an extracellular location.
Isometric tension and myofilamental cross-sectional area in striated muscle
Authors: Helander Einar , Thulin Carl-Axel
Published: December 2017

Isometric tension in tetanically stimulated calf muscles was examined in vivo in 3 rabbits and 18 cats. In two cats the gastrocnemius and soleus muscles were studied separately. After determination of the isometric tension the muscles were dissected and their water content, total N content, and protein composition were analyzed. On this basis it was possible to calculate that part of the cross-sectional area of the muscle fibers which consisted of myofilaments. The recorded maximum isometric tension was related to the myofilamental cross-sectional area. Under the given experimental conditions, the calf muscles developed a tension of 108 ± 5 g/mm2 cross-sectional area. Higher values resulted from tests of individual calf muscles than from combined muscles.
Fatty acid metabolism during norepinephrine-induced thermogenesis in the cold-acclimatized rat
Authors: Hannon John P. , Larson Anna M.
Published: December 2017

Intravenous infusion of cold-acclimatized rats with l-norepinephrine (2 µg/min) caused a marked increase in metabolic rate and rectal temperature and a sustained reduction of the respiratory quotient. Prior to infusion the blood and liver concentrations of nonesterified fatty acids (NEFA) were greater in cold-acclimatized than in control rats. Upon infusion blood NEFA levels were markedly increased, but reached the same ultimate concentration in both groups. In vitro studies showed that liver tissue from cold-acclimatized rats had a significantly higher capacity for NEFA (palmitate) oxidation than liver tissue from controls. In vitro studies also showed that epididymal fat tissue from cold-acclimatized rats was considerably more sensitive to NEFA-mobilizing action of norepinephrine than similar tissue from controls. Continuous measurements of respiratory gas exchange during acute cold exposure (5 and –15 C) or cold-acclimatized rats caused reduction of the RQ, limited to the transition stage from a lower to higher metabolic steady state. We conclude that: a) norepinephrine-calorigenesis is primarily supported by oxidation of NEFA; b) greater calorigenic response to norepinephrine in cold-acclimatized animals is due to improved capacity to form and oxidize NEFA; c) norepinephrine is not the sole mediator of nonshivering thermogenesis. We suggest that the calorigenic action of this hormone is either limited to periods of acute cold stress or exerted in conjunction with other neurohumoral agents during chronic exposure.
Citrate and action of vitamin D on calcium and phosphorus metabolism
Authors: Guroff Gordon , DeLuca Hector F. , Steenbock Harry
Published: December 2017

Pantothenic acid and pyridoxine deficiencies in rats greatly minimized the rise in serum citrate following vitamin D administration without affecting the rise in serum calcium, serum phosphorus, and femur ash. In addition, pyridoxine deficiency reduced the response of bone citrate to the administration of vitamin D. The administration of cortisone acetate to rats on a low-calcium diet completely prevented the response of serum and bone citrate to vitamin D administration while having no effect on the response of serum calcium to vitamin D. These findings make it unlikely that an elevated citrate content of extracellular fluid and bone mediates the basic effects of vitamin D on mineral metabolism.
Effect of histamine on adrenal 17-hydroxycorticoid secretion in unanesthetized dogs
Authors: Suzuki Tatuzi , Hirai Kenji , Kurouji Haruhiko Yoshio Ken-Ichi , Yamashita Kazukuni
Published: December 2017

Dogs with previously sectioned dorsal spinal roots (T11-L3) were used in experiments for collecting the adrenal venous blood without anesthetizing or evoking any pain. Intravenous injection of histamine in doses of 0.05–1.0 mg/kg body wt. was demonstrated to produce a marked acceleration of 17-hydroxycorticoid secretion. The time courses of changes in the secretion rate after injection of varying doses of histamine are compared.
I131 accumulation by the lactating rat mammary gland
Authors: Grosvenor Clark E.
Published: December 2017

The mammary glands of lactating rats fed a low-iodine diet accumulated 50% of an injected I131 dose or five times as much as the thyroid gland and twice as much as excreted by the kidneys in 17–24 hr. Rats which accumulated greater amounts of I131 in their mammary glands had significantly lesser thyroidal I131 uptakes. KClO4 and methimazole significantly reduced accumulation of I131 in milk, KClO4 being the more potent. Methimazole acted primarily in reducing the binding of I131 to milk protein. The concentration of I131 in milk, trichloroacetic acid-precipitable I131 in milk and in plasma, and ratio of milk I131 to plasma I131 were significantly reduced by the addition of iodide to the diet. The amount of I131 in the milk was not correlated with the amount of milk secreted. Exogenous thyroxin inhibited thyroidal I131 uptake but did not influence accumulation of I131 by the mammary gland. Injection of thyrotrophin restored thyroidal uptake of I131 but did not affect accumulation of I131 by the mammary gland.
Influence of serotonin upon optic evoked potentials, EEG, and blood pressure of cat
Authors: Koella W. P. , Czicman J. S.
Published: December 2017

In cats immobilized with Flaxedil and supplied with local anesthesia in the areas adjacent to the surgical openings, the optic evoked response, the EEG, and the blood pressure were studied in their reaction to intracarotid serotonin (5-HT). Our earlier findings that the effect of 5-HT on the amplitude of the evoked response is the compound effect of the drug action of at least three receptor sites have been confirmed. The carotid sinus area (factor x), the brain stem (factor y) and the specific sensory pathways (factor z) appear to be the three responsive sites. In comparison with the earlier experiments performed on Dial-anesthetized animals, the x-factor and the y-factor in the present series are shifted, in general, toward the facilitory side. Not much difference is found if the z-factor is compared in the two different conditions. EEG activation occurs in response to intracarotid serotonin. This effect is positively correlated to the dose of 5-HT. Injections into the innervated carotid sinus produce considerably stronger effects than those into the denervated carotid sinus. With repeated injections of 5-HT the effect upon the evoked potentials is altered in its quantitative and temporal aspects. The blood pressure usually reacts to 5-HT with a rise. With larger doses of 5-HT this rise is more pronounced and often preceded by an initial drop.
Cardiovascular responses to ischemia, hypoxia, and hypercapnia of the central nervous system
Authors: Downing S. Evans , Mitchell Jere H. , Wallace Andrew G.
Published: December 2017

The hemodynamic responses to CNS ischemia and to perfusing the CNS with hypoxic or hypercapnic blood were observed in the dog. A dual, rotating disc oxygenator system was employed to separately perfuse the brachiocephalic artery distribution following confirmed bilateral carotid sinus area denervation. Cerebral ischemia produced a marked increase of blood pressure, peripheral vascular resistance, heart rate, and atrial and ventricular contractility. These same responses were also produced by lowering the pO2 or raising the pCO2 of the CNS perfusate, but were somewhat less marked. The hemodynamic findings resulting from these interventions are similar to those observed during systemic hypoxia. It is, therefore, suggested that the gas composition of the blood perfusing the central nervous system may importantly influence the response of the organism to systemic hypoxia.
Creatine, creatine phosphate, and creatinine levels in hypoxia hypertrophied rat hearts
Authors: Edman C. D. , Silvers N. P. , Gangloff E. C. , Krause R. F.
Published: December 2017

Cardiac hypertrophy was produced in adult, male, albino rats by prolonged exposure to reduced atmospheric pressure. Creatine, creatine phosphate, and creatinine levels in these hypertrophied hearts were all significantly reduced from that of control rats.
Effects of histamine, acetylcholine, and norepinephrine on gastric vascular resistance
Authors: Jacobson Eugene D.
Published: December 2017

The vasoactive properties of three naturally occurring substances which influence gastric secretion were investigated in the gastric vascular bed. A constant flow perfusion of the canine stomach was employed and vascular pressures were recorded in response to a wide range of drug doses. Histamine was found to decrease vascular resistance appreciably in the concentration range 0.01–0.50 µg/ml blood perfusing the stomach. Gastric vascular resistance declined in response to acetylcholine infusion when the concentration exceeded 0.10 µg/ml blood. Norepinephrine increased resistance to blood flow appreciably when perfusion concentration was greater than 0.05 µg/ml blood. It was also found that the responses to histamine and norepinephrine were esssentially the same whether the agents were infused locally or systemically for calculated concentrations in the gastric perfusate. These findings substantiate the concept that gastric secretory stimulants dilate, and that gastric secretory inhibitors constrict the gastric vascular bed.
Thermal stimulation of electrical activity of single units of the preoptic region
Authors: Nakayama Teruo , Hammel H. T. , Hardy J. D. , Eisenman J. S.
Published: December 2017

Single unit activity has been recorded in the hypothalamus and preoptic region of cats anesthetized with urethan during local hypothalamic heating and cooling. Heating was accomplished by radio frequency current (3.7 megacycles/sec) and heating and cooling by circulating warm and cold water through small steel thermodes placed 4–6 mm on each side of the midline. Local tissue temperature was recorded by thermocouples and by thermistors. It was observed from a study of about 1,000 neurons that a) about one neuron in five increased its rate of spontaneous discharge with increase in local temperature from 32 to 41 C (Q10 = 5–15); b) 80% of the units did not respond to temperature change by changing their spontaneous discharge rate in the 34–41 C temperature range; c) thermally sensitive neurons were found only in the midline region immediately rostroventral to the anterior commissure; d) no units were found for which the discharge frequency increased by decreasing the local temperature.
Effect on blood glucose concentration of changes in availability of glucose to the brain
Authors: Sakata Kazuki , Hayano Shigeo , Sloviter Henry A.
Published: December 2017

In the unanesthetized rabbit, systemic blood glucose concentration was measured periodically during the course of a slow, continuous infusion of glucose solution via the internal carotid artery. Under conditions otherwise identical, the same experiment was performed in the same rabbit, but the infusion was intravenous. In 7 of 14 such pairs of experiments, the curve of glucose concentration versus time was significantly lower for the intracarotid experiment and in the other seven cases there was no significant difference between the two curves. These results suggest that the brain responds to the increased concentration of glucose of its environment and by some mechanism acts to return it toward normal. Experiments were done in the same way with 2-deoxy-d-glucose, a substance which produces a cellular glucopenia. Of seven pairs of experiments, the systemic blood glucose curve was markedly higher in intracarotid infusion in three cases, moderately higher in two cases, and not significantly different in two cases from the curve for the intravenous infusion. These results suggest that the brain responds to decreased availability of glucose and acts, by way of the sympathetic nervous system, to raise the blood glucose concentration.
Regional blood flow and cardiac output during acute hypoxia in the anesthetized dog
Authors: Murray John F. , Young I. Maureen
Published: December 2017

The circulatory effects of breathing low concentrations of oxygen were studied in ten anesthetized dogs. Simultaneous measurements were made of cardiac output (indicator dilution technique) and blood flow to the head, kidney, and hind limb (electromagnetic flowmeters). Four experiments were performed with the addition of succinylcholine to inhibit the ventilatory response to hypoxia and maintain pCO2 constant. A rise in cardiac output and mean arterial pressure occurred which was significantly correlated to the decrease in arterial oxygen saturation. No threshold for these responses was found. Blood flow tended to increase during hypoxia in the regions studied but the responses were variable and only the change in renal blood flow had a significant correlation to arterial oxygen unsaturation. Systemic and regional vascular resistances during hypoxia varied both in direction and magnitude of change. The preponderant effects of hypoxia influence cardiac output more than peripheral vascular resistance.
Center of arterial pressure regulation during rotation of normal and abnormal dogs
Authors: Smith Edward E. , Guyton Arthur C.
Published: December 2017

Dogs were rotated about a horizontal transverse axis. By shifting the axis of rotation along the length of the animal's body it was possible to find a point at which arterial pressure remained almost constant in all positions of rotation. In most normal dogs such an axis lay in the neck a few centimeters cephalad to the sternum. Denervation of carotid sinus and aortic pressoreceptors caused a caudal shift of the axis; total spinal anesthesia did also, and to a much greater degree. This study demonstrates that pressure regulatory mechanisms operate to maintain a constant arterial pressure in the neck, probably for the minimizing of postural alterations of cerebral blood flow
Drug inhibition of circulatory response to endotoxin in dogs
Authors: Tsagaris Theofilos J. , Koehler J. Albrecht , Kuida Hiroshi , Hecht Hans H.
Published: December 2017

The effect of combined pretreatment with a drug that inhibits the synthesis of serotonin, alpha-methyl 3,4-dihydroxyphenylalanine, and an antihistamine, promethazine hydrochloride, on the hemodynamic response to E. coli endotoxin was studied in a group of six dogs. Compared with the characteristic endotoxin response obtained in six control experiments, pretreated animals given endotoxin demonstrated significantly less elevation of pulmonary artery (PAP) and portal venous (PVP) pressures, and less striking fall in systemic arterial pressure (SAP) and cardiac output. Considering the average maximum changes alone, expressed as percentage of preendotoxin base-line values, in the control vs. pretreated groups, respectively, results were as follows: SAP, 36 vs. 84%; cardiac output, 31 vs. 66%; PAP, 162 vs. 118%; PVP, 338 vs. 186%. This investigation lends additional support to the concept that many of the cardiovascular effects of endotoxin are mediated through the release of vasoactive agents such as histamine and serotonin.
Fibrinogen-I131, T-1824, and red cell-Cr51 spaces following hemorrhage
Authors: Baker Carleton H.
Published: December 2017

Altered hemodynamics following hemorrhage causing extended mixing time of indicators, fluid shifts, and changes in indicator disappearance slopes were studied in 17 anesthetized splenectomized dogs. Fibrinogen-I131, T-1824, and red cell-Cr51 spaces were determined simultaneously and the animals were bled 11.3 ml/kg. There was a significant decline in concentration of the three indicators that could not be accounted for on the basis of hematocrit or plasma protein concentration changes. After 20 min stabilization, the spaces were again measured, and the animals were bled an average of 17.7 ml/kg (to an arterial pressure of 60 mm Hg). The decline in indicator concentration was again observed. After allowing the animals to stabilize for 20 min, the spaces were again measured. There was a mobilization of red cells following the first hemorrhage and a trapping of red cells following the second hemorrhage. Fibrinogen-I131 and T-1824 spaces agreed closely with the expected spaces calculated from changes in hematocrit or plasma protein concentration. The fibrinogen space was consistently less than the T-1824 space. The ratio BVcells/ BVfibrinogen significantly increased from 0.92 to 0.99 following the hemorrhages. This suggested a possible redistribution of "extra plasma" or a smaller involvement of extravascular space in the plasma volume determination. BVcells/ BVT-1824 did not change following the hemorrhages. Possible causes for the decline in indicator concentration following hemorrhage are discussed.
Cardiac versus peripheral effects of left stellate ganglion stimulation
Authors: Kot Peter A. , Nunez Colon S. , Freis Edward D. , Rose John C.
Published: December 2017

The direct effects of left stellate ganglion stimulation were studied in dogs with an intact circulation and with the left ventricle bypassed. In both preparations left stellate stimulation was associated with an increase in myocardial contractile force, an elevation in pulmonary arterial pressure, and no change or a slight fall in right atrial pressure. Before left ventricular bypass, left stellate stimulation was accompanied by a rise in both systolic (+46 mm Hg) and diastolic (+22 mm Hg) pressure. With the left ventricle eliminated from the circulation and systemic flow controlled with a mechanical pump, changes in systolic (+13 mm Hg) and diastolic (+7 mm Hg) pressure were negligible. These observations confirm that the hypertensive response is due predominantly to augmented cardiac output and that peripheral vasoconstriction plays a minor role.
Small blood vessel responses to sympathetic stimulation
Authors: Davis Darrell L.
Published: December 2017

Three segments, an arterial, a small blood vessel, and a venous segment of the vasculature of the dog paw were isolated and studied separately to determine the temporal characteristics and the magnitude of response of each segment to a standard sympathetic stimulation. The small vessel segment responded the most rapidly, and the venous segment the least rapidly to the stimulation. The small vessel segment exhibited the most rapid recovery. Complete recovery of the arterial and venous segments required 3–5 min. A control rate of blood flow was reestablished through the arterial segment within 30–60 sec, and through the venous segment in 3–5 min, after cessation of stimulation. In some experiments blood flow was stopped completely by the sympathetic stimulation, and in all experiments the digital artery pressure was markedly decreased by the stimulation. The arteries were more effective than the arterioles in curtailing flow during the stimulation period. However, the veins were the most effective during the recovery period.
Effect of heart rate on action of ouabain on Ca exchange in guinea pig left atria
Authors: Gersmeyer E. F. , Holland W. C.
Published: December 2017

The influence of heart rate on the action of ouabain on contraction and calcium (Ca) exchange in guinea pig atria has been examined. Concentrations of the drug producing a therapeutic effect (positive inotropic effect) at a given frequency became progressively more toxic (arrhythmias, negative inotropic effect) as the rate of beat increased. Paralleling these changes, one noted a progressively increasing effect of the drug to enhance Ca exchange. When contractures occurred, a rise in tissue Ca was observed. It was concluded that the therapeutic effect of ouabain results from a further mobilization of tissue Ca that occurs with each heartbeat. It was suggested that when the rate of mobilization of tissue Ca by the drug exceeded a critical value, toxic manifestations appear. Thus, it would seem from the data that the basic mechanism of the therapeutic and toxic effects of ouabain are but an expression of varying degrees of the same chain of physicochemical events: namely varying degrees of effect on Ca exchange in the myocardium.
Growth and body composition of the mouse
Authors: Cheek Donald B. , Holt A. B.
Published: December 2017

Twenty groups of male mice composed of one or more litters of a definite age were subjected to whole-body analysis. The weight of mice, when plotted against age, demonstrated an S-shaped growth curve. The same curve was shown by fat and by water when plotted against age. Plotting fat-free dry solid on age revealed two linear relationships with time, separated by the period of growth spurt. The time of maximal growth rate was about 37 days—a time at which the first estrus occurs in the female. Total electrolyte and water revealed a linear relationship with fat-free dry solid from the preweaning period (4–21 days) and up to maturity (21–40 days) when regression equations were calculated for each group. Following maturity (40–150 days) a decrease in the slopes of regression lines was demonstrated. The over-all relationship was curvilinear. The findings predict that during the main period of growth total K (and growth of cell mass) is probably linearly related to body protein or fat-free dry solid (protein plus mineral ash). During the weaning period, mice show loss of electrolyte and water per unit of fat-free dry solid. Reduction in K per unit of fat-free dry solid is possibly associated with an increased deposition of protein and a delay in increase of cell volume. The phenomenon may be related to prematurity.
Sodium fluxes in isolated frog brain
Authors: Zadunaisky José A. , Curran Peter F.
Published: December 2017

The properties of a preparation of isolated frog brain bathed in a Ringer's solution have been examined in order to determine whether it is suitable for study of ion movements. The preparation can be maintained in a steady state with respect to Na and water content for up to 5 hr. Under our conditions the washout of Na24 from preloaded brains appears to be made up of two components, a fast one having a half time of 7.4 min and a slow one having a half time of 54.6 min. The slow component of washout was affected by ouabain, iodoacetate, and cyanide and by reduced temperature, and appears to represent a cellular compartment. The fast component was not affected by metabolic poisons and appears to represent an extracellular space making up approximately 24% of the wet weight of the tissue. The effective diffusion coefficient of Na in this space was found to be 0.82 x 10–5 cm2/sec. A method of calculating Na fluxes from the data on Na24 washout is discussed.
Inhibition of gastric emptying in mice by bacterial endotoxins
Authors: Turner Mary Marshall , Berry L. Joe
Published: December 2017

Mice injected with bacterial endotoxins exhibit a rapid reduction of food and water intake, to a degree dependent on the magnitude of the dose. Using phenol red solution as a tracer, it has been demonstrated that gastric emptying is inhibited by endotoxin injection; that the effect is rapid (within 10–15 min); and that it occurs whether the endotoxin is injected intraperitoneally or intravenously. With four different endotoxin preparations, inhibition is maximal at one-tenth of the ld50. Significant inhibition may be caused by between 1/20 and 1/100 of an ld50, depending on the preparation used. Injection of cortisone acetate reduces the inhibition of gastric emptying caused by endotoxin injection; intravenously injected Proferrin, however, does not increase the response, although it sensitizes the mouse to the lethal effects of endotoxin.
Submandibular salivary gland enlargement by feeding pancreatin to rats
Authors: Wells Herbert , Voelkel Edward F.
Published: December 2017

Addition of pancreatin, a dried and defatted preparation of porcine pancreas, to the diet of rats resulted in a marked increase in both the fresh and dry weights of the submandibular salivary glands. A range of pancreatin doses, from 0.25 to 4% resulted in a dose-response curve with little effect below 0.5%, a plateau above 2%, and a straight line between the 0.5 and 2% dose levels. After cessation of pancreatin administration, there was a marked recession in the weight of the enlarged glands. Prior unilateral extirpation of the superior cervical sympathetic ganglion inhibited the response to dietary pancreatin of the submandibular gland on the operated side. In contrast to its effect when ingested, pancreatin had no significant effect on gland weight when administered by stomach tube. When added to the diet at only one-tenth the dose of pancreatin, alpha-chymotrypsin (3x crystallized) had an equal effect on gland weight. Chymotrypsinogen (3x crystallized) and trypsin (2x crystallized) were without significant gland growth activity. A partially purified extract of pancreatin had almost the same relative potency as crystalline alpha-chymotrypsin.
Effect of intrapleural pressure on pulmonary shunt through atelectatic dog lung
Authors: Finley T. N. , Hill T. R. , Bonica J. J.
Published: December 2017

During spontaneous breathing of oxygen, the pulmonary shunt through the left lung, made atelectatic by occlusion of its airway, was calculated from the O2 and CO2 tension of the arterial and mixed venous blood. At intrapleural pressure swings of -3 to -12 cm H2O, the relative blood flow through the atelectatic lung was reduced to 21.6% of the pulmonary blood flow (normal 45%). With wider swings of intrapleural pressure, average -7.5 to -24 cm H2O, the relative blood flow through the atelectatic lung increased to 45% of the pulmonary blood flow, probably because resistance to blood flow increased in the overdistended right lung. The pulmonary shunt through atelectatic lung varied directly with the increased negativity of the intrapleural pressure.
Role of factors XII, XI, and IX in serum and plasma-induced thrombosis
Authors: Reimer Stanley M. , Thomas Duncan P.
Published: December 2017

The possible in vivo relationship between the known coagulation factors and experimental thrombus formation is discussed. A thrombogenic activity can be elaborated in human plasma from inert precursors by exposure of the plasma to a foreign surface. This plasma activity can only induce stasis thrombi when infused into animals that have factor IX (plasma thromboplastin component, PTC). A more potent thrombogenic activity exists in normal human serum, devoid of thromboplastin and thrombin, which cannot be equated with either activated factor XI (plasma thromboplastin antecedent, PTA) or factor IX alone, but which probably represents a combination of both these factors. All recognized clotting factors except factor IX have previously been shown to be distinguished from the thrombogenicity of normal serum. The coagulation of human blood is believed to proceed initially through the sequential activation of factors XII, XI, and IX. The present data, obtained using in vivo thrombus formation as the end point, are consistent with these interpretations of in vitro observations.
Cell water, sodium, and potassium in stimulated red and white mammalian muscles
Authors: Sréter F. A.
Published: December 2017

Potassium and sodium concentration and inulin space were measured in samples of rat soleus, plantaris, and gastrocnemius muscles after indirect stimulation in situ for 4 min, 30 min, and 6 hr. Two samples were taken from the gastrocnemius muscle: one from its outer layers, containing mostly white fibers, and another from the deep layer containing relatively more dark fibers. The cationic changes which follow low-frequency stimulation are largest in white gastrocnemius fibers, and decrease in this order: plantaris muscle, red gastrocnemius fibers, and soleus. When the stimulation frequency was increased, predominantly red components of the triceps surae also showed a marked cationic "debt." The same occurred with an intermittent tetanus alternating with stimulation at 10/sec. Intermittent tetanus alternating with resting periods or continuous tetanus did not cause any significant change in cationic distribution.
Taste preferences for lithium chloride by adrenalectomized rats
Authors: Nachman Marvin
Published: December 2017

Page 219: Marvin Nachman, "Taste preferences for lithium chloride by adrenalectomized rats." The numbers on the ordinate (intake in ml) of figure 2 should read: 0, 10, 20, 30, 40, 50, 60, 70, rather than 0, 1, 2, 3, 4, 5, 6, 7.
Bone composition and Ca45 retention in fowl as influenced by egg formation
Authors: Hurwitz S.
Published: December 2017

Ca45 was intravenously administered to laying hens close to the time of ovulation. Groups of five birds were killed at intervals ranging from 30 min to 14 days, after dosing, and calcium, phosphorus, and radioassays were made on their blood plasma, on ends and cortical and medullary segments of their tibias and femurs, and on eggs laid previous to killing. Radioactivity in blood plasma and eggs decreased with time. There were no significant changes in amount and calcium and phosphorus content of tibia and femur segments during one and more reproductive cycles. Radioactivity of bone segments increased to 2 hr after dosing and later markedly declined, paralleling eggshell deposition. Specific activity of the medullary segment was higher than that of ends or cortical segment. It is suggested that the decline in radioactivity of bone is caused mainly by exchange with stable calcium during its transfer from gut to eggshell, although resorption of bone may also take place. The high specific activity of medullary bone 2 days after dosing suggests a greater turnover of calcium in this segment than in the other segment studied.
Effect of sodium deficiency of the action potential of the smooth muscle of ureter
Authors: Kobayashi Makoto , Irisawa Hiroshi
Published: December 2017

Action potentials of the smooth muscle of cat ureter were studied by using ultramicroelectrodes. Among 193 penetrations, the resting potential averaged 45 mv and the amplitude of action potential 32 mv. In four instances a slight overshoot was recorded. Action potential consisted of a relatively rapid rising phase followed by a slow repolarization phase, and its duration was about 0.3 sec. Effects of sodium deficiency on action potential were studied by using three different sodium substitutes. Both the height and the rising rate of action potential decreased as the concentration of extracellular sodium was reduced, indicating that the action potential of ureter muscle can be explained on the basis of sodium theory. The duration of the action potential was prolonged when sucrose or choline chloride was used as a sodium substitute; on the other hand, it shortened when tris chloride was employed. The essential role of sodium ions in the development of the action potential in ureter muscle is discussed.
Role of sympathetic nervous system in surviving acute hemorrhage
Authors: Chien Shu
Published: December 2017

Twenty unanesthetized, chronically sympathectomized-splenectomized dogs were subjected to rapid hemorrhages varying from 29 to 49% of the control blood volume (determined with Cr51 and T-1824). One to two hours after hemorrhage, the blood volume was again determined and an average fluid replacement of 6.3% of control blood volume was found. The blood volume remaining after hemorrhage was correlated with the fate of the dog. The 50% mortality (or 50% survival) point corresponds to a residual blood volume of 70.5% of control blood volume or 57.5 ml/kg. These values are higher than those previously reported on splenectomized dogs with sympathetics intact, which had 50% mortality with a residual blood volume of 61.0% or 49.5 ml/kg.
Cardiac lymph: flow rates and composition in dogs
Authors: Miller Albert J. , Ellis Anthony , Katz Louis N.
Published: December 2017

Cardiac lymph was obtained for study from 15 stock dogs. Rates of cardiac lymph flow were found to be substantially greater than previously reported. Anoxia observed in two dogs increased cardiac lymph flow. Data are presented on the protein, chloride, sodium, and potassium content of cardiac lymph and compared with values in arterial plasma. These base-line studies on the flow and composition of cardiac lymph help lay a groundwork for future investigations under varying hemodynamic circumstances. The lymph represents an important parameter of cardiac function; it arises from the interstitial space and can be expected to reflect the composition of the area drained. Complete metabolic and electrolyte balance studies of an organ like the heart should take into consideration the amount and composition of the lymphatic outflow.
Sympathetic stimulation and small artery constriction
Authors: Davis Darrell L.
Published: December 2017

The outflow of blood from a digital artery of the dog hind paw to the atmosphere was recorded to determine if this outflow could be stopped completely in response to high-frequency sympathetic stimulation. In 5 of the 12 dogs studied, the outflow was stopped completely by stimulation of the peripheral stump of the sciatic nerve at 15 v, 20–25 stimuli/sec, a pulse duration of 5 msec, and a total stimulation period of approximately 60 sec. In those experiments in which complete cessation of flow was achieved, pressure pulsations were obliterated from the digital artery pressure tracing and the mean pressure decreased to atmospheric pressure levels. In the remaining dogs, in which flow was not stopped, pressure pulsations were evident in the digital artery pressure tracings throughout the stimulation period and mean pressures decreased to values ranging from 15 to 2 mm Hg.
Mechanism of lysine-induced kaliuresis
Authors: Walker W. Gordon , Dickerman Herbert , Jost Luis J.
Published: December 2017

Kaliuresis induced by the intravenous infusion of l-lysine monohydrochloride persists when experiments are done in the presence of pre-existing metabolic acidosis produced by NH4Cl administration. The relation between lysine-induced kaliuresis and the rate of urinary sodium excretion indicates that the K excretion is quite sensitive to changes in sodium excretion when sodium excretory rates are low but this relation tends to disappear at high rates of sodium excretion. Thus the final mechanism whereby K enters the urine in these experiments appears to be sodium-for-potassium exchange. Increasing infusion rates of l-lysine monohydrochloride result in the appearance of an alkaline urine despite a progressive extracellular metabolic acidosis. Under these conditions the rate of bicarbonate excretion may exceed 80% of the amount of bicarbonate filtered. The data are best explained by postulating the l-lysine monohydrochloride infused at pH 7.4 produces an extracellular acidosis and intracellular alkalosis, thereby suppressing the kidney's ability to secrete H+ ion and facilitating K+ secretion.
Effect of angiotensin II on urinary dilution in normal man
Authors: Gill John R. , Barbour Benjamin H. , Slater J. D. H. , Bartter Frederic C.
Published: December 2017

Free water clearance (CHH2O) was studied in five normal subjects and in a patient with diabetes insipidus before and during the infusion of angiotensin II (Ciba), .2 µg/min. With angiotensin, CHH2O fell markedly, with only small changes in urinary osmolality both in the normal subjects and in the patient with diabetes insipidus. The fall in CHH2O was accompanied by a fall in UNaV, effective renal plasma flow (ERPF), and glomerular filtration rate (GFR). A physiological dose of Pitressin (25 mU/hr) given after the angiotensin, abolished CHH2O and markedly increased urinary osmolality while UNaV, ERPF, and GFR returned toward normal. The results may be best explained as a direct effect of angiotensin on renal hemodynamics, to decrease filtered sodium and water. Reabsorption of an increased fraction of filtered sodium and water by the proximal tubule would limit the amount reaching the diluting segment of the nephron and excreted in the urine. A possible role for angiotensin in the impaired water excretion of certain disease states, such as Addison's disease and congestive heart failure was suggested.
Coagulation factors in normal and hemophiliac-type swine
Authors: Cornell C. N. , Muhrer M. E.
Published: December 2017

A group of general coagulation tests and a specific assay for antihemophilic factor ( AHF) was performed on five normal and two hemophiliac-type swine. There was no apparent evidence that an inhibitor of thromboplastin existed. Although the thromboplastin generation test was normal in all animals tested, a modified test employing a dilution technique demonstrated that a plasma abnormality existed in the hemophiliac-type swine. Serum from both normal and hemophiliac-type swine was found to correct the plasma recalcification time of human plasma known to be deficient in plasma thromboplastin component (factor IX). The results indicate that the hemophiliac-type swine are grossly deficient in AHF.
Cr51-labeled endotoxin distribution in granulocytopenic animals
Authors: Herion John C. , Herring William B. , Palmer Jeffress G. , Walker Richard I.
Published: December 2017

Endotoxin, injected intravenously in small doses, is removed from the blood of nongranulocytopenic and granulocytopenic, HN2-treated rabbits at a rate similar to normal controls, but more slowly than in tolerant animals. Significant nonplasma activity is present in animals with only a few circulating granulocytes, re-emphasizing the role of platelets in binding endotoxin. In addition to the liver and spleen, the bone marrow is a significant reservoir for endotoxin removed from the blood, even in animals with markedly hypocellular marrows. Thus, granulocytes would not appear to contribute significantly to the removal of small doses of endotoxin. Pretreatment of rabbits with HN2 does not appreciably alter either the clearance of endotoxin from blood or its distribution in tissues.
Effect of total adrenalectomy on gastric secretion in chronic gastric fistula rats
Authors: Bralow S. P. , Komarov S. A. , Shay H.
Published: December 2017

Basal gastric secretion of rats with chronic fistulas was studied before and after adrenalectomy or sham operation. A marked exponential fall in concentration and output of free and total acid resulted in virtual anacidity within 3–7 weeks following adrenalectomy. Failure in parietal cell secretion was not accompanied by significant decrease in parietal cell mass. Pepsin concentration and output as well as volume also fell exponentially but more gradually. No significant change in total chloride concentration occurred. Relative influence of concentration in determining output was 30 times greater than volume for free acid, 3 times greater for total acid, and twice as great for pepsin. Volume was responsible for almost all variability in total chloride output. Time after adrenalectomy influenced variability of volume and acid output twice as much as concurrent decrease in body weight.
Mercaptomerin effect on p-aminohippurate transport in man and pentobarbitalized dog
Authors: Letteri Joseph M. , Wesson Laurence G.
Published: December 2017

The effects of mercaptomerin on Tmpah in man and the pentobarbital-anesthetized dog were studied by standard clearance methods. Tmpah was depressed to 60% of control values during the 4th to 6th hr of pentobarbital anesthesia. Mercaptomerin administration to the pentobarbitalized dog prevented the depressant effect of pentobarbital on Tmpah from appearing, in that no significant difference in Tmpah was noted between control periods and postmercurial periods in these experiments. Injection of dimercaprol to pentobarbitalized animals receiving mercaptomerin depressed Tmpah to values expected in anesthetized animals which had received no mercaptomerin. Dimercaprol had no effect in anesthetized animals not receiving mercaptomerin. In man, mercaptomerin depressed Tmpah to 50% of control values whether the mercurial was injected before or after commencement of PAH-loading.
Dose response to carbachol and norepinephrine in rat hypothalamus
Authors: Miller Neal E. , Gottesman Kay S. , Emery Nona
Published: December 2017

One microliter of various concentrations of carbachol or norepinephrine was injected via a chronic cannula into the "feeding-drinking" area of the hypothalamus of satiated rats. Doses of 2.7 through 24 x 10–10 m of carbachol elicited drinking of increasing amounts of water, but progressively higher doses elicited less drinking, some lethargy, and then convulsions. Similar, but probably less, responsiveness occurred to injections of the ventromedial nucleus. Control and weak solutions did not elicit drinking; no dose of carbachol elicited appreciable eating of solid, or drinking of a liquid food, namely, a Metrecal solution made slightly salty so that normally thirsty rats preferred water to it. Doses of from 24 through 216 x 10–10 m norepinephrine elicited drinking of salty Metrecal ( P < .10), while 648 x 10–10 m elicited reliable consumption of this food. Still higher doses elicited less "eating," some lethargy, and eventually a few convulsions. Control and weak injections did not elicit eating. No drinking of water was elicited at any level of norepinephrine. Histologically determined placement of cannulas correlated with amount of response for both substances.