bluuebunny/crossref_metadata_2025 huggingface dataset:
Autoregulation of blood flow by oxygen lack
Authors: Ross Joe M. , Fairchild Hilton M. , Weldy Joe , Guyton Arthur C.
Published: December 2017

The effect of hemoglobin oxygen saturation upon blood flow through the hind leg of the dog was studied by perfusing the femoral arteries of five normal dogs with blood, the oxygen saturation of which was varied between 100% and 0%, and by perfusing the femoral arteries of nine spinal animals with blood, the oxygen saturation of which was varied between 100% and 10%. The blood saturation was controlled in the following manner: The blood was obtained from the lower lobe of the left lung as it was respired with a mixture of nitrogen and oxygen. By varying the ratio of the mixture, the blood oxygen saturation could be controlled exactly. Decreasing the oxygen saturation stepwise caused a correlated increase in blood flow through the leg. The results have shown that blood flow in the nonspinal dogs increased to an average of 3.4 times the normal value as oxygen saturation fell from 100% to 0%. In the spinal dogs blood flow increased to an average of 3.1 times normal as oxygen saturation fell from 100% to 10%. These experiments demonstrate that the local tissues can autoregulate their blood flow to help maintain an adequate supply of oxygen.
Heat loss from the heart in dogs
Authors: Adolph Robert J. , Pinardi Gianni , Rushmer Robert F.
Published: December 2017

Thermistors were inserted into the coronary sinus and the root of the aorta in anesthetized dogs to record the temperature difference between the left ventricular coronary inflow and outflow. Coronary sinus flow was directly measured with an indwelling cannula. Heat loss from the coronary vasculature was then calculated as the product of the temperature gradient and the coronary sinus flow. The average temperature difference during control periods was about .5 C (range, .24–.88 C). Isoproterenol, l-epinephrine, and acetylstrophanthidin all increased the temperature gradient, the coronary sinus flow, and, therefore, the myocardial heat loss. A small but significant amount of heat was lost from the epicardial surface of the left ventricle to the lungs in the closed-chest dog. Direct physical measurements of heat loss avoid many of the uncertainties inherent in estimates of wasted energy based on the energy equivalent of myocardial oxygen consumption.
Effect of disuse atrophy on pectoralis muscle and blood in the pigeon
Authors: George J. C. , Vallyathan N. V.
Published: December 2017

Disuse atrophy in the breast muscle of the pigeon was induced by applying a plaster cast on the wings, which were kept in a dorsally extended position. Lipolytic activity in the breast muscle and blood serum was determined at different intervals from 1 day to 2 months. A higher enzyme activity in the muscle and a corresponding fall in the enzyme activity in blood serum were observed during the 1st week of atrophy. Fat and water contents in the muscle were also estimated. During the first 2 weeks there was an increase in water content of the muscle. A sudden increase in fat content was observed on the 1st day of atrophy. Later the fat content gradually decreased, and by the end of 2 months the fat content was found to be less than that in the normal pigeon. The physiological significance of such changes in lipase activity and fat content is discussed.
Effect of cortisol and estradiol on tissue binding of testosterone
Authors: Parra Francisco , Reddy William J.
Published: December 2017

Simultaneous administration of cortisol and testosterone-4-C14 to the rat results in a decrease in the concentration of radioactivity in several tissues similar to that observed when the testosterone-4-C14 is diluted with an equal amount of nonlabeled testosterone. Estradiol, when given simultaneously with the labeled testosterone, did not show the same effect. These findings are interpreted that testosterone and cortisol compete for the same sites of binding in the tissues examined. The subcellular distribution in muscle, kidney, and liver following intravenous injection was almost identical to that found following in vitro addition to the tissues.
Failure of L-arginine to protect in ammonia intoxication: its role in urea source
Authors: Villarreal Herman , Ronces Regino , Sánchez Vidal , Arcila Heriberto
Published: December 2017

The protective effect of l-arginine against ammonia intoxication produced by ammonium chloride was investigated in dogs. When l-arginine was administered together with NH4Cl, the increase in blood ammonia was approximately 25% less than when NH4Cl alone was given. Similar results with these substances were observed in dogs with hyperammoniemia. This protection, however, was only apparent since the variation was not statistically significant. Blood urea rose when NH4Cl was infused. When l-arginine was added, this increase was even greater and the difference was statistically significant. l-Arginine alone produced a definite rise in blood urea without blood ammonia concentration being affected. The conclusions are drawn that l-arginine does not protect against ammonia intoxication by NH4Cl and that increase in blood urea is due mainly to the metabolism of exogenous arginine rather than to the transformation of ammonia into urea.
Potassium contracture and calcium influx in frog's skeletal muscle
Authors: Lorković Hrvoje
Published: December 2017

The height and the duration of the K contracture of frog's sartorii ( Rana esculenta) is a function of extracellular calcium. The rate of inhibition of the K contracture in a Ca-free solution and the rate of recovery from such inhibition in a Ca-containing solution measured by the percentage increase and decrease of the height of the K contracture are not alike, the recovery being quicker. The apparent diffusion constant of Ca as calculated from recovery data is about ten times, in Na-free solutions about 100 times, smaller than that calculated from inhibition data. The additional Ca influx connected with contractures, measured by Ca45 entry, is almost proportional to the extracellular Ca concentration. However, the size of K contractures of and the Ca influx into muscles soaked in Ca-free nitrate solutions suggests that both the "removable" as well as the "more firmly surface-bound" calcium take part in the K contracture.
Density and composition of the lean body compartment and its relationship to fatness
Authors: Pitts Grover C.
Published: December 2017

Specific gravity of the eviscerated carcass was determined by water displacement on 26 male and 21 female adult guinea pigs. Fat (petroleum ether extraction) and water (freeze-drying) were determined on the entire body, and total adipose tissue was estimated. Specific gravity of the fat-free body (FFB) and the adipose-free body (AFB) was calculated for this and other studies on steers and rats where possible. Specific gravity of the FFB ranged around 1.09 ± 004–008 (mean ± sd) and was independent of weight of the FFB but possibly correlated with fatness. Specific gravity of the AFB was approximately 1.10 with the same order of variability. Purely biological variability must be smaller and indicates physiological regulation. The H2OFFB was 75% (guinea pig) and 71% (steer) with standard deviations of around 1%. Positive correlations between fatness and weight of both FFB and AFB in this population study corroborate similar findings in in vivo studies on man. Increments in fat, lipocytes, and nonadipose material were in the ratio 60:12:28. Indirect evidence indicates participation of bone in short-term weight changes. A mechanism is suggested for regulation of muscle:bone ratio and specific gravity in the AFB.
Growth of hamsters during continual centrifugation
Authors: Briney Stanley R. , Wunder Charles C.
Published: December 2017

Female Syrian hamsters have been subjected to continual centrifugation for a period of 4 weeks at four or five times the earth's gravity. Animals were 5 weeks of age at the onset of exposures. Although an increased gravitational field curtails body growth, certain organs were found to show an increase in their relative mass when compared to control littermates. The heart, diaphragm, gastrocnemius muscle, lungs, kidney, and head showed a relative increase in mass, and the femur bones of centrifuged hamsters showed a relative increase in length.
Interactions of neutral and acidic amino acids in renal tubular transport
Authors: Webber William A.
Published: December 2017

The effects of intravenous infusions of a variety of neutral and acidic amino acids on the plasma concentrations and excretions of naturally occurring amino acids were studied in dogs. Conventional clearance techniques were used, and the amino acid concentrations were determined by ion exchange column chromatography. Infusion of either l-glutamic acid or l-aspartic acid caused a gross increase in the plasma concentration and excretion of the other. Infusions of neutral amino acids including glycine, l-alanine, l-leucine, l-methionine, l-proline, and l-phenylalanine caused some minor changes in the endogenous plasma amino acid concentrations. They produced increases in the excretion of other neutral amino acids and, in some cases, of acidic and basic amino acids as well. In general, amino acids with long side chains were most effective in inhibiting reabsorption while cyclic side-chain compounds were less effective. There appear to be at least three somewhat separable mechanisms for renal tubular reabsorption of amino acids in dogs.
Chemical and histological space determinations in rabbit heart
Authors: Johnson John A. , Simonds Mary A.
Published: December 2017

The extracellular space of perfused rabbit heart ventricles was estimated by chemical and histological techniques. Sucrose and thiocyanate were used for the chemical space estimations. The method proposed by Chalkley following fixation by freeze substitution was used for the histological extracellular space determination. The extracellular space fraction was altered by using perfusing solutions of different osmotic activity to shrink or swell the cells. The magnitude of the tissue water loss or gain was determined by weighing the heart. Using the assumption that the cells alone changed in volume during an osmotically induced weight change, an alteration in the fractional extracellular space was predicted from the original chemical or histological space determination and the magnitude of the weight change. This predicted change when compared to the observed change in the histological and chemical spaces always agreed in direction with the measured values of both the histological and chemical spaces but was in better quantitative agreement with the values from the chemical technique.
Viscous drag and energy transfer of pulsatile flow in large arteries
Authors: Evans Robert L. , Bernstein Eugene F. , Lary Darrel L.
Published: December 2017

Early results of simultaneous measurement of pressure gradient and flow in the thoracic aorta of the dog during systole are used in calculations of viscous drag and energy transfer of actual pulsatile flow. Viscous drag is large when the flow is small, and small when the flow is large, so that almost all the energy of the pulse wave is transmitted along the vessel. The amplitude of the viscous drag is a much greater fraction of the amplitude of the pressure gradient than is predicted by the Navier-Stokes equation, which is only theoretical and may assume an unrealistic form of viscous drag during pulsatile flow.
Generation of prothrombin-R with plasma protein fractions
Authors: Barnhart Marion I. , Das B. C.
Published: December 2017

An activity of blood concerned in prothrombin activation is reported that was not previously recognized. Prothrombin-R was produced from a prothrombin derivative prepared with lysosomes after addition of various plasma fractions. The reaction was optimal at pH 7.9, and thrombin-C was not formed. Cohn fractions from either rabbit or human plasma generated prothrombin-R, although only fraction IV (alpha globulin plus) gave complete regeneration. Further purification of Cohn fractions was achieved with DEAE-cellulose chromatography. All fractions gave 100% yield of prothrombin-R. An immunoelectrophoretically pure alpha globulin had the highest specific activity. Partially purified gamma or beta globulin and albumin, also, were effective in that order. Immunologic data support the view that the alpha globulin content of these other fractions was responsible for generation of prothrombin-R. Most likely the active agent is an enzyme. Accordingly the plasma constituent which generates prothrombin-R is designated enzyme-R.
Inhibition of fibrin polymerization by fibrinogen proteolysis products
Authors: Latallo Zbigniew S. , Fletcher Anthony P. , Alkjaersig Norma , Sherry Sol
Published: December 2017

The action of fibrinogen proteolysis products in inhibiting fibrinogen-fibrin conversion by thrombin has excited considerable interest because of its possible significance in blood coagulation. This reaction has been investigated by following the polymerization of highly purified fibrin monomer, in the presence and absence of fibrinogen proteolysis products, by a spectrophotometric procedure. Fibrinogen proteolysis products inhibited polymerization at low ratios of proteolysis products/monomer, and both early and late phases of polymerization were equally affected. Polymerization rates of fibrin monomer, as apart from the gel point, were little influenced by reaction temperature over the range 15–35 C, and the degree of inhibition produced by fibrinogen proteolysis products was likewise independent of temperature. A linear relationship was demonstrated between the degree of inhibition to polymerization and the ratio of fibrinogen proteolysis products to monomer. It is suggested that the inhibitory mechanism involves the coupling of fibrinogen proteolysis products with monomer in a "competitive" manner.
Contraction of depolarized smooth muscle by electric fields
Authors: Sperelakis Nick
Published: December 2017

Smooth muscle strips of the circular layer of cat intestine depolarized with potassium (150 mEq/l.) were subjected to electric fields. The field strengths necessary to generate equal tensions were much higher in depolarized muscle (5–25 v/cm) than in non-depolarized muscle (0.5–2 v/cm). It was found that maximal tension generated varied linearly, within limits, with strength and duration of the field. A longitudinal field, with respect to the long axis of the fibers, was more effective than a transverse field. Tensions generated in sinusoidal a-c fields decreased markedly between 40–1,000 cycles/sec; the low tensions generated at the higher frequencies could be increased by increasing the field strength. With rectangular d-c pulses, tension generated at 10,000 cycles/sec was greater than that at 10 cycles/sec. Treatment with a detergent irreversibly blocked the action potential-dependent contractions but did not prevent the field-induced contractions. A single, brief contracture generally occurred immediately after addition of acetylcholine to the bath (5–50 µg/ml); in addition, the field-induced tension was markedly increased without an effect on the resting tension. Prior atropinization blocked both acetylcholine effects. Acidification of the bathing solution enhanced the field-induced tensions. Sr replaced Ca in the field contractions but not in excitation-contraction coupling. It is suggested that, in depolarized smooth muscle, displacement of charged particles by the application of large voltage gradients leads to the generation of tension; the excitation-contraction coupling process appears to be bypassed.
Localization of gold in mouse brain in relation to gold thioglucose obesity
Authors: Debons Albert F. , Silver Lawrence , Cronkite Eugene P. , Johnson Horton A. , Brecher George , Tenzer Doris , Schwartz Irving L.
Published: December 2017

Administration of gold thioglucose led to the development of hyperphagia and obesity in mice; this confirmed findings by previous investigators. By employing neutron activation analysis and radioautography, it was observed that this syndrome was associated with focal accumulation of gold in the hypothalamus. Animals treated with gold thiomalate failed to show any hypothalamic localization of gold radioautographically or any evidence of the syndrome of hyperphagia and obesity. In addition, other foci of gold localization were found in gold thioglucose-treated but not in the gold thiomalate-treated animals. Gamma spectroscopy studies made possible quantitative measurements of the gold content in the brains of both treated groups. Gold thioglucose-treated as well as gold thiomalate-treated animals had appreciable quantities of gold in the brain proper. Phosphorus 32 generated by neutron activation of the sulfur moiety of gold thioglucose proved to be insignificant in its contribution to the radioautographic findings. Implication of the above findings for the glucostatic theory of appetite regulation is discussed.
Effects of blood pH changes on potassium excretion in the dog
Authors: Toussaint Charles , Vereerstraeten Pierre
Published: December 2017

K+ excretion rate was measured at normal as well as at rising plasma K+ concentration in intact, in K-depleted, and in acetazolamide-treated dogs submitted to acute blood pH changes. The results indicate that, for any given value of glomerular filtration rate, K+ excretion rate is determined by at least three factors: 1) plasma K+ concentration, 2) blood pH level, and 3) presumably, the H+ gradient across the luminal border of the distal tubule. The data further suggest that most of the filtered K+ is reabsorbed by the proximal tubule, even in conditions of high filtered loads.
Changes in GFR and CHH2O before and after repair of K deficiency in rats
Authors: Holliday Malcolm A. , Egan Thomas J.
Published: December 2017

Clearance of inulin and CHH2O were compared in control rats and in rats after 25–35 days of potassium deficiency. The latter had a decrease in inulin clearance and a proportional decrease in CHH2O. After 5–13 days of repair in the potassium-deficient group the clearance of inulin was normal and the CHH2O was normal or possibly high. A slight impairment in ability to dilute urine was noted.
Removal and mobilization of individual free fatty acids in diabetic dogs
Authors: Gold Martin , Miller Harvey I. , Spitzer John J.
Published: December 2017

Gas chromatographic analysis of individual free fatty acids showed elevated concentrations of the five major fatty acids in the arterial blood of acutely diabetic dogs. The percentage contributions of oleic and linoleic acids were also elevated. Insulin lowered both elevated concentrations and percentages. All major fatty acids were released into the epigastric vein from adipose tissue. Total fatty acid composition of adipose tissue was similar in normal and diabetic dogs. Adipose tissue free fatty acid composition was similar to that of blood and dissimilar to composition of total fatty acids. Myocardium failed to remove oleic acid in diabetic dogs unless insulin was administered. Consistent net removal by the liver of palmitoleic, stearic, and oleic acids occurred in diabetic animals.
Volume of distribution of C14-labeled tris(hydroxymethyl)aminomethane
Authors: Holmdahl Martin H:Son , Nahas Gabriel G.
Published: December 2017

Seven cats and three dogs, after ligature of the renal vessels, were given 27.3–13.7 µc/kg body wt. of C14-labeled 2-amino-2-hydroxymethyl-1, 3-propanediol or tris(hydroxymethyl)aminomethane (THAM). One milliliter per kilogram of 10% inulin was simultaneously administered. Arterial pH was maintained close to 7.40. At this pH, 30% of THAM (pK 7.82 at 37 C) is un-ionized. Samples of plasma were withdrawn at 15, 30, and 60 min and 2, 3, 4, 5, and 6 hr. Plasma inulin concentration reached a plateau within 1–2 hr and had distributed in 21% of body weight. No C14 was detected in the expired CO2. After 15 min the volume of C14 space was significantly larger ( P < 0.02 > 0.01) than the inulin space. Plasma radioactivity approached a plateau after 4 to 6 hr, at which time the C14 was distributed into a volume corresponding to 55 ± 9% of body weight. If THAM is distributed evenly throughout body water and is not significantly degraded, it tends to equilibrate within 6 hr with the intracellular compartment.
Respiratory sensitivity to carbon dioxide in cross-circulated dogs
Authors: Kao Frederick F. , Suntay Remedios G. , Li William K.
Published: December 2017

The effect of CO2 on ventilation was studied in cross-circulated dogs. In these experiments the recipient dog's head was perfused exclusively by arterial blood from the donor dog through anastomoses of the common carotid arteries of the donor to the vertebral arteries of the recipient. The carotid arteries of the recipient dog, as well as its muscles in the neck, were tied. The injection of lipiodol and latex did not reveal leakage from the recipient's head to its body or vice versa. Ventilation and arterial Pco2 of both dogs were determined before, during, and after the inhalation of carbon dioxide of 3, 5, and 7% with 20% oxygen and balance nitrogen by the donor for 20 min or more. The sensitivity of the respiratory centers of both dogs to Pco2 was similar, as indicated by the regression lines relating ventilation in both dogs as a function of arterial Pco2 of the donor dog only. The blood of the recipient's body was hypocapnic when its head was receiving hypercapnic blood. The sensitivity coefficient in both dogs was similar to that of decerebrate dogs during CO2 inhalation. It is inferred that the central CO2 chemoreceptors can account for all the ventilatory response to CO2 inhalation.
Effects of activity on contractions of normal and dystrophic mouse muscles
Authors: Sandow Alexander , Brust Manfred
Published: December 2017

Excised gastrocnemii of normal and dystrophic mice, directly stimulated in long series of isometric twitches or tetani, show different fatigue patterns. During a series of 1,200 maximal twitches, developed tension drops much more slowly in dystrophic responses so that final output relative to initial is: dystrophic, 70%, normal, 10%. A similar but smaller difference holds for a tetanus series. Pronounced quantitative and qualitative distinctions between the two muscle types also appear in the changes of other twitch characteristics: relaxation time and rate, and contraction rate but not time. The qualitatively distinct fatigue pattern of the dystrophic muscle is dependent not on diffusional differences stemming from its smaller bulk, but on some basic dissimilarity inherent in the dystrophic myopathy. The possible nature of this dissimilarity is discussed in relation to general functional features of fatigue and to special aspects of dystrophic muscle concerned with metabolism, intensity property of the active state, and role of the relaxing factor.
Separation of sodium and potassium ion carrier systems in crustacean motor axon
Authors: Wright Ernest B. , Tomita Tadao
Published: December 2017

When a microscopic area (100 µ length) of the lobster single motor axon is subjected to isotonic potassium solution and the membrane potential maintained at resting level by an applied voltage, a slow prolonged depolarization may be elicited by adequate cathodal stimuli. This response is due to activity of the potassium carrier system. If some sodium chloride is included in the high potassium solution, both spike and prolonged depolarization may be initiated as a spike-dip-plateau. With normal amount of sodium in excess potassium solution the dip is absent, but the membrane resistance shows a remarkable increase at the juncture of the spike and the plateau. Chronaxie values of the spike are 0.4–0.5 msec, of the slow response 2.1–2.2 msec. In potassium-rich media containing sodium two separate inward currents are recorded during a voltage clamp, an early spikelike current, and a late prolonged one. It is concluded that two separate ion carrier systems are activated in a nerve membrane during excitation, one specific to sodium ions, the other to potassium ions, each system possessing quite different and independent characteristics from the other.
Effect of oxytocin structural changes on rat renal excretion of Na, K, and water
Authors: Rosas R. , Barnafi L. , Pereda T. , Croxatto H.
Published: December 2017

The common action of oxytocin on the smooth musculature of the uterus and on the renal excretion of sodium, potassium, and water suggests a relationship between the two effects. In order to investigate this possibility, the action of oxytocin treated with chymotrypsin and with sodium thioglycollate on sodium, potassium, and water excretion was studied. These agents greatly reduce the uterotonic activity of the hormone as well as its effect on electrolyte and water excretion in rats. Equivalent uterotonic doses of oxytocin, Val3-oxytocin, and Phe2-Tyr3-oxytocin were assayed on the excretion of electrolytes and water. Excretion of sodium and potassium produced by Val3-oxytocin was less than that produced by oxytocin. Phe2-Tyr3-oxytocin was approximately one-ninth as active as oxytocin in this respect. In studies with low doses of oxytocin it was established that 0.25 mU was necessary to increase sodium excretion while 0.5 mU had to be administered in order to increase potassium as well.
Na, K, Ca, and Cl exchange in guinea pig ileum
Authors: Chujyo Nobuyuki , Holland William C.
Published: December 2017

Exchange of Na, K, Ca, and Cl in the tubular segment (mucosa inside) of guinea pig ileum was studied. Influx and efflux of K were estimated by the method of Keynes and Lewis to be 1.36 and 4.00 pmole cm–2 sec–1, respectively, which are in agreement with those given by general transfer equation. In the case of Na and Cl, fluxes estimated by both methods were not consistent with each other. This fact, as well as time course of Ca inflow, indicates a complex type of exchange of these three ions, and did not permit an accurate estimation of fluxes. Pilocarpine (5 x 10–6 m) caused a temporary increase in K efflux, temporary decrease in K influx, and little or no effect on Na exchange during the initial 30-min interval and, after a 10-min delay, a temporary decrease in Cl efflux. The drug increased the rate of Ca exchange, presumably by releasing Ca from a bound form in the tissue. This effect is believed to be the molecular basis of pilocarpine-induced contraction.
Specificity of the transport system for neutral amino acids in the hamster intestine
Authors: Lin Edmund C. C. , Hagihira Hiroshi , Wilson T. Hastings
Published: December 2017

The specificity of the active transport system for neutral amino acids has been studied with everted sacs of hamster intestine. Amino acids with modifications or replacements of the carboxyl, amino, or α-hydrogen groups were poorly transported and were poor inhibitors of the transport of other l-amino acids. The carboxyl group must remain free, the amino group must not be in the tertiary or quaternary state, and the α-hydrogen can not be replaced by a methyl group without serious effect on the transport rate. It was concluded that the l-amino acids were distinguished from the d-isomers by the interaction of the carrier with the carboxyl group, the amino group, and the α-hydrogen. The side chain of the amino acid must be nonpolar but there is relatively little restriction on its structure.
Absence of arteriovenous anastomoses in anesthetized sheep
Authors: Hamlin Robert L. , Marsland William P. , Smith C. Roger
Published: December 2017

Microspheres, approximately 50 µ in diameter and labeled with scandium 46, were injected into the jugular vein in three sheep and into the left ventricle in one. Radioactivity was recovered only from the lungs after jugular injections. After left ventricular injection, the fraction of radioactivity recovered from the lungs corresponded closely to the proportion of cardiac output carried by the bronchial circulation. It appears that no physiologically significant arteriovenous anastomoses exist in sheep under the experimental condition.
Genetic differences in serum cholesterol in chickens
Authors: Hardy Lester B. , Auger H. V. , Wilcox F. H.
Published: December 2017

Studies were conducted on the underlying mechanism for differences in serum cholesterol in two lines of chickens. The serum level of free and combined cholesterol was higher in the high line than the low line; no significant differences were observed in the serum level of fatty acids or phospholipids. The lines did not differ in the weights of several organs or in the cholesterol level of the adrenal, liver, brain, or testis. The high line had a higher serum cholesterol level than the low line, from hatching to 16 weeks of age. The lines did not differ in their response to fasting, which makes it improbable that a dietary influence accounts for the line differences. They responded similarly to injections of testosterone, estrogens, cortisone, or thyroxin.
Cadmium enhancement of proximal tubular sodium reabsorption
Authors: Vander Arthur J.
Published: December 2017

Stop-flow studies were performed to localize the site of cadmium action on renal sodium reabsorption. In the untreated dog undergoing mannitol diuresis, a maximal lumen:plasma sodium gradient was established across the proximal tubule during free flow with no further lowering of luminal concentration during ureteral occlusion, Naprox/NaFF = 1.02 ± .05. During occlusions after cadmium, sodium concentrations in proximally trapped fluid were reduced below free-flow values, Naprox/NaFF = 0.85 ± .08. This difference between treated and untreated animals was statistically significant ( P = < .001) and indicates that cadmium enhances proximal sodium reabsorption. Although distal sodium patterns were unaltered by cadmium, it was not possible to rule out a possible distal site since distal sodium reabsorption is already virtually complete during occlusion in the untreated animal. Cadmium, given intravenously as Cd115, was not excreted in the urine.
Epinephrine release and liver glycogen levels after carbon tetrachloride administration
Authors: Rubinstein David
Published: December 2017

Two hours after the intraduodenal administration of carbon tetrachloride to rats, a decrease in the adrenal epinephrine level was detected, with a concomitant increase in serum epinephrine level. A simultaneous rise in liver phosphorylase activity and blood glucose concentration was seen. Two hours later these values all had returned to normal. Depletion of liver glycogen and increase in serum transaminase were noted 7 hr after CCl4 administration. Ergotamine could diminish the depletion of glycogen but had no effect on transaminase activity. Phenoxybenzamine did not inhibit liver glycogen depletion, but significantly decreased the transminase activity. Both antiadrenergic drugs were injected 1 hr after CCl4 administration. These results indicate that release of epinephrine due to the administration of CCl4 occurs much earlier than the 20-hr period previously reported. Decrease in the resultant depletion of glycogen had no effect on the increase in liver damage.
Some physical, metabolic, and sensory components in the appetite for glucose
Authors: Jacobs Harry L.
Published: December 2017

Glucose appetite in satiated, hungry, or thirsty rats was measured by ingestion of glucose and of saccharin solutions in free-choice tests. Type, concentration, and number of choices were determined with and without intragastric or intraperitoneal loads of metabolizable and nonmetabolizable sugars, urea, or NaCL. Taste and calories were evaluated as rate modulators in ad libitum feeding. Gastric distention, sweetness, and the chemical and osmotic properties of ingested glucose were evaluated as sources of satiety signals. The results indicate that: a) Taste is not a factor in ad libitum glucose intake; the caloric density of the solution is implicated. b) The satiety effect of intragastric glucose loads in independent of gastric distention or its potential osmotic effects. However, glucose intake may be related to the general state of hydration. c) The response to glucose and sucrose loads suggests the operation of a preabsorptive chemoreceptor system. The use of glucose appetite as a tool in the concomitant investigation of hunger and thirst is discussed.
Tissue tolerance to hyperthermic blood perfusion of dog hind limb
Authors: Reed William A. , Hopkins Lenly
Published: December 2017

This work was designed to attempt to define the tolerance of the lower extremity of the dog to induced hyperthermia by passing blood from a carotid artery, through an extracorporeal circuit, and re-entering at the femoral artery to circulate through the distal tissues of the extremity. In 27 perfusions, early death of the animal prevented adequate evaluation of the effects of perfusion in nine instances. Tissue temperatures up to 45 C of 1-hr duration were tolerated with complete recovery of function. Angiograms demonstrated a normal peripheral vascular pattern. Tissue temperatures above 46 C resulted in marked edema during perfusion followed by necrosis several days later. Reversible damage resulted from short duration perfusions of 45–46 C. Calcification was present at the arteriotomy site in some of these animals. The tissues of the dog extremity may be heated to 45 C for short periods with subsequent recovery of normal function.
Amygdalectomy: effects in cats and a survey of its present status
Authors: Summers T. B. , Kaelber W. W.
Published: December 2017

The behavioral changes ascribed to bilateral removal of the amygdala and piriform lobe, especially "angry" behavior, has been restudied in 13 cats. Excision of this region was proved in 9. While observed for periods of 6 months to more than 1 year, no state of intractable savageness replaced previously normal tame behavior. Indifference to the presentation of live mice was a curious behavioral deviation in 11 animals, in striking contrast to their preoperative responses. Two animals with incomplete removals became moderately hostile to observers after several months, as indicated by hissing and growling; however, despite such unfriendly demonstrations they could be handled with impunity. The only significant histological difference between these and the unchanged animals was damage to the ventrolateral portion of the hypothalamus on one side. Whether this could be pertinent requires further experimentation, but a possibility of bilateral functional derangement from this type of lesion remains.
Na, K, Ca, and Cl exchange in guinea pig ileum
Authors: Chujyo Nobuyuki , Holland William C.
Published: December 2017

Page 909: Nobuyuki Chujyo and William C. Holland, "Na, K, Ca, and Cl exchange in guinea pig ileum." The unit of the ordinate of each figure in Figure 3 should read 109 c/m/Eq instead of 103 c/m/Eq.
Effects of protoveratrine on coronary blood flow of the renal hypertensive dog
Authors: West James W. , Foltz Elwood L.
Published: December 2017

In renal hypertension, protoveratrine decreased coronary blood flow, cardiac oxygen consumption, arterial and venous oxygen saturation, coronary arteriovenous oxygen difference, mean arterial blood pressure, cardiac output, cardiac work, cardiac efficiency, cardiac rate, total peripheral resistance, coronary resistance, respiratory rate, and minute volume. The decrease was significant in all functions except coronary blood flow, coronary venous oxygen saturation, and cardiac output. The results of these experiments indicate that in the renal hypertensive animal, a therapeutically beneficial effect was derived from protoveratrine on the circulation by its ability to decrease the work of the heart (lowering the elevated mean arterial pressure) and the coronary vascular resistance while maintaining coronary blood flow and cardiac output within normal levels. The less advantageous effect of protoveratrine on circulation resulted from its respiratory inhibiting effect which reduced the arterial blood oxygen saturation. Although a small decline in coronary venous oxygen saturation was noted, the coronary flow and oxygen delivery in face of the reduced arterial oxygen saturation was apparently adequate to maintain a normal cardiac activity.
Renal regulation of bicarbonate loads during hypothermia
Authors: Kanter G. S.
Published: December 2017

The ability of the hypothermic kidney to handle massive exogenous bicarbonate loads was studied in five dogs given 2.6% NaHCO3 plus 0.75% creatinine and 0.1% PAH intravenously at the rate of 4.0 ml/min. The renal hemodynamic pattern was typical of hypothermia with decreasing GFR, RPF, and blood pressure and increasing renal resistance. Urine pH rose to 7.95 while arterial pH, corrected to body temperature, reached a maximum of 7.56 and then slowly declined to 7.51 at 27 C. In spite of the fall in GFR, the urine flow, under the influence of the hyperosmotic load, increased progressively throughout the exposure. Although the bicarbonate load presented to the tubules remained near control levels throughout most of the exposure, the absolute reabsorption of bicarbonate fell from a normothermia value of 1.5 mEq/min to 0.9 mEq/min at 27 C. In terms of mEq of bicarbonate reabsorbed/100 ml of glomerular filtrate, bicarbonate reabsorption increased from 2.1 mEq/min at 38 C to 2.7 mEq/min at 27 C. On the basis of the progressive increase in the clearance ratio for bicarbonate, from a normothermia value of .15 to .34 at 27 C, it is concluded that a depressing effect of cold on the tubular transport of bicarbonate had occurred.
Distribution of body water in the camel (Camelus dromedarius)
Authors: Banerjee Sachchidananda , Bhattacharjee Ramesh Chandra
Published: December 2017

The distribution of water in the different body compartments were determined in the adult male Indian camels with one hump. The average distributions were as follows: serum volume, 5.9% of body wt.; blood volume, 8.3% of body wt.; total body water (urea space), 68.7% of body wt.; extracellular water (thiocyanate space), 23.3% of body wt.; intracellular water, 45.4% of body wt.; and interstitial water, 17.4% of body wt. The serum and blood volumes of the camel were higher than similar values in other ruminants. When these values were compared with similar values in man, it was observed that the camel had significantly higher serum volumes, total body water, and intracellular water volumes. The capacity of the camel to hold more water might help the animal in withstanding the deprivation of water for a prolonged period in comparison to other animals.
pH of isolated resting skeletal muscle and its relation to potassium content
Authors: Miller Ronald B. , Tyson Ian , Relman Arnold S.
Published: December 2017

Intracellular pH of isolated rat diaphragm was measured with both a C14-DMO method and a tissue CO2 technique. The values for intracellular pH by each method, although slightly different, changed in parallel under most experimental conditions. Acute, severe potassium depletion in vitro had no detectable effect on intracellular pH, nor did prior depletion in vivo followed by incubation in a potassium-free bath. This was true whether or not the potassium-depleted muscle was exposed to normal or elevated extracellular levels of bicarbonate, and was unaffected by the presence of cationic amino acids in the bath. Acute repletion of previously potassium-depleted muscle resulted in a small rise in cell pH, but this was no greater than that produced by loading normal tissues with potassium. It is concluded that under the conditions of these experiments there is no evidence of intracellular acidosis in potassium-depleted skeletal muscle. Rat diaphragm can lose up to half its potassium content in vitro without detectable increase in hydrogen ion concentration.
Effect of rapid and transitory changes in blood and urine pH on NH4 excretion
Authors: Sullivan Lawrence P. , McVaugh Michael
Published: December 2017

The Chinard technique of close arterial injection has been adapted to permit a closer study of the relationship of pH to ammonium excretion. NaHCO3, Na4Fe(CN)6, HCl, and creatinine hydrochloride solutions were injected into a renal artery of a dog undergoing osmotic diuresis while 15-sec serial urine and renal venous blood samples were being collected. Because of the difference in transit time between blood and urine the effect of the alteration in blood pH upon ammonium excretion could be seen before the filtered portion of the injection reached the urine. Thus NaHCO3 in the blood raised urine ammonium concentration while urine pH remained relatively constant. Later as NaHCO3 appeared in the urine, pH rose and urine ammonium concentration fell. Na4Fe(CN)6, which decreased blood pH, produced opposite effects. HCl and creatinine hydrochloride caused an immediate fall in both urine pH and ammonium concentration which persisted during the appearance of the injection in the urine. The results of these experiments are interpreted in terms of the theory of nonionic diffusion.
Triton hypercholesteremia: cause or consequence of augmented cholesterol synthesis
Authors: Byers Sanford O. , Friedman Meyer , Sugiyama Toshiko
Published: December 2017

Rats were observed to become hypercholesteremic within 90 min after intravenous administration of Triton (oxyethylated tertiary octylphenol formaldehyde polymer) detergent. At this time, intravenously-injected acetate-1-C14 was found to be incorporated into liver cholesterol to the same extent by Triton-injected animals and by their control. Twenty-four hours after Triton injection, however, acetate was incorporated into cholesterol to a greater extent by Triton-injected rats than it was by control rats. Thus, an increase in the rate of cholesterol synthesis is not the primary cause of the Triton hypercholesteremia but appears to be only an indirect effect of Triton.
Effect of parasympathetic stimulants on Ca45 transfer in vitro in rat parotid glands
Authors: Dreisbach Robert H.
Published: December 2017

Page 497: Dreisbach, Robert H., "Effect of parasympathetic stimulants on Ca45 transfer in vitro in rat parotid glands." Title should read, "Effect of parasympathetic stimulants on Ca45 transfer in vitro in rat lacrimal glands." Throughout the paper where parotid gland is written, it should read extraorbital lacrimal gland.
Micropuncture study of ammonia excretion in the rat
Authors: Glabman Sheldon , Klose R. M. , Giebisch Gerhard
Published: December 2017

Ammonia has been determined in blood and in samples of tubular fluid obtained by micropuncture at various sites along the nephron from two groups of rats, one untreated and the other pretreated with ammonium chloride. Ammonia has been found in tubular fluid from all segments of the nephron, the concentrations being generally higher in those animals which were pretreated with ammonium chloride. In addition, there is a tendency for the concentration of ammonia to increase as the site of micropuncture progresses along the nephron. In the proximal tubule, concentrations of ammonia have been found which are greater than can be accounted for solely by the extraction of water in this segment. This is taken to indicate tubular addition of ammonia at this site. Since the increments of ammonia along the nephron generally exceed that which could be due to water reabsorption, it is concluded that all parts of the nephron contribute to urinary ammonia excretion.
Adrenal-dependent effect of 4,4'-methylenedianiline on endometrial carbonic anhydrase
Authors: Yamashita Kazukuni
Published: December 2017

The effect of 4,4'-methylenedianiline on the endometrial carbonic anhydrase of rabbits was investigated. A marked increase in the carbonic anhydrase of the uterine endometrium could be induced by treatment of Clauberg rabbits with methylenedianiline, the degree being characteristic of graded doses administered. Methylenedianiline also exerted a typical activation of the endometrial enzyme even in ovariectomized rabbits. However, with adrenalectomized ovariectomized rabbits methylenedianiline failed to produce the increase in the endometrial enzyme. The response is considered to be adrenal-dependent. Furthermore, treatment with cortisone effected a substantial inhibition of the endometrial carbonic anhydrase response to methylenedianiline. It is thus indicated that the endometrial carbonic anhydrase response to 4,4'-methylenedianiline is due to the secretion of adrenal progestogen resulting from a block of adrenal corticosteroidogenesis.
Flow and oxygen saturation of blood in the anterior ciliary vein of the dog eye
Authors: Cohan Bruce E. , Cohan Sandra B.
Published: December 2017

A technique is described which provides the first data on blood flow and oxygen values for the tissue drained by the anterior ciliary vein of the dog eye. Measurements indicated that the tissue drained by this vein has the following properties: a) an unusually high venous oxygen saturation (90%) and, therefore, an exceedingly low arteriovenous oxygen difference (0.9 ml/100 ml); b) a very high rate of blood flow (100 ml/100 g min); c) a relatively low rate of oxygen consumption (0.7 ml/100 g min); d) a venous oxygen capacity significantly higher than that in control arterial blood. Some physiologic implications of these findings are discussed.
A mechanism for absorption of sodium chloride solutions from the canine gall bladder
Authors: Grim Eugene
Published: December 2017

Absorption of NaCl solutions of different concentrations and of autogenous plasma from the canine gall bladder was studied. Net water flux was linearly related to osmotic activity of the luminal solution, and was positive (in the direction, lumen to blood) up to 420 mOs/liter. Net Na and Cl fluxes were positive above luminal concentrations of 90 and 65 mEq/liter, respectively, and rose with increasing concentration up to that point at which net water flux changed direction; beyond this, they remained essentially constant. Several models for the transport mechanism were considered, with particular emphasis on the question of passive versus active water transport. The only one which was reasonably consistent with experimental observation was as follows. Active transport of solution from lumen to blood by a solution pump like pinocytosis occurred at a rate independent of luminal concentration. The remainder of the water flux was as bulk flow due to the osmotic gradient. Na and Cl transport could be entirely accounted for by movement in the "pinocytotic" fluid and by diffusion in the convective field arising from the osmotic transport of water.
Parallel inhibition of spontaneous and antigen-induced platelet histamine release
Authors: Shore P. A. , Alpers H. S.
Published: December 2017

Small amounts of histamine and serotonin are released spontaneously in vitro from blood cells of normal rabbits. Similar to release induced by antigen-antibody reaction, spontaneous release is calcium dependent but occurs even in the presence of a high concentration of heparin. Spontaneous release is inhibited by tosylarginine and tosylarginine methyl ester, agents which also inhibit antigen-induced release. Benzoylarginine, benzoylarginine methyl ester, lysine ethyl ester, and arginine have little effect on either spontaneous or antigen-induced release. A heat-stable factor in plasma can effect platelet amine release. The results suggest that factors involved early in the coagulation mechanism may be responsible for platelet amine release under these conditions.