bluuebunny/crossref_metadata_2025 huggingface dataset:
Reversibility of endocrine changes produced in guinea pigs by exposure to cold
Authors: Sobel Harry , Haberfelde George C. , Reeves Albert E.
Published: December 2017

Guinea pigs were exposed continuously to a temperature of 2–4 C for 6 months. They were then reacclimatized to room temperature, and after 4–6 months certain tests were carried out. During control collections and following exposure to cold the previously cold-exposed animals exhibited urinary corticoid excretion values which were approximately 10% below those of their controls. Following intraperitoneal injection of ACTH the response was approximately 20% greater. However, these differences were not statistically significant. Oral glucose tolerance tests revealed definite evidence of reduction in tolerance in the previously cold-exposed animals. Six animals exhibited 150-min values which exceeded by more than 20 mg/ 100 ml the highest value observed in the controls. Fourteen others whose values fell within this limit exhibited a statistically significant increase in the 150-min value as compared with the controls. The PBI values were the same in each group. There were no histological residues in the pituitary, adrenal, pancreas, and thyroid glands.
Calcium turnover in different bone segments of laying fowl
Authors: Hurwitz S.
Published: December 2017

The turnover of calcium in various bone segments was studied by a single-dose technique in Nicarbazin-treated hens, and by a long-term feeding of a Ca45-labeled diet in normal laying hens. Nicarbazin treatment prevented ovulation and shell formation with only a slight effect on plasma Ca concentration. In the treated hens, exchangeable Ca comprised 3.3%, 0.5%, and 5.2% of the Ca in femur ends, cortical, and medullary segments, respectively. Accretion rate was highest in the medullary and lowest in the cortical segment. Results of the long-term Ca45 feeding indicate the following sequence for the turnover rate of Ca in bone segments: tibia medullary = femur medullary >> femur ends > tibia ends = sternum > humerus ends > femur cortical > tibia cortical = humerus cortical. During a 12-day period at least 70% of Ca in the medullary segment was replaced. On continuous feeding of Ca45 to laying hens, plasma and egg-shell specific activity reached a maximum level, higher than that of the diet, between 12 and 20 days.
Specific localization of α-ketoglutarate uptake to dog kidney and liver in vivo
Authors: Selleck Burnell H. , Cohen Julius J.
Published: December 2017

Net uptake of infused α-ketoglutarate (α-KG) occurs almost exclusively in dog kidney and liver; in contrast, lactate or pyruvate uptake occurs in most organs. The following observations support these conclusions: 1) in measurements of steady-state net renal and whole-body uptake of α-KG, lactate, and pyruvate, kidney takes up ≈50% of the total α-KG utilized as compared to lactate (≈15%) or pyruvate (≈17%); 2) liver and kidney extract more α-KG from blood than do the lower extremities, brain, intestine, or heart; 3) exclusion of either the kidneys or the liver, or both, from the circulation shows that these organs are the major determinants of the rate of α-KG clearance from blood. The virtual volume of α-KG distribution in the hepatectomized, nephrectomized dog is approximately that of extracellular fluid. The selective uptake of α-KG is compared to the membrane transport of p-aminohippurate (PAH) by these two organs. It is suggested that the general, and perhaps primary, function of the PAH transport system is to move specific metabolites to sites of dissimilation in liver and kidney.
Effect of osmotic diuresis on intrarenal solutes in diabetes insipidus and hydropenia
Authors: Appelboom J. W. , Brodsky W. A. , Scott W. N.
Published: December 2017

Changes in composition of renal solutes were studied in normal and in diabetes insipidus (D.I.) dogs subjected to varying degrees of solute (mannitol) loading. In both D.I. and hydropenic states, solute loading induced decreases in concentration of medullary solutes, and consequently decreases in corticomedullary gradients of solute concentration. The maximal level of papillary osmolality was associated with excretion of maximally hypertonic urine (nonloaded hydropenic states). The minimal level of papillary osmolality was not associated with excretion of hypotonic urine (D.I. states), but with excretion of slightly hypertonic urine during massive solute loading in normal hydropenic states. Hypertonicity of renal papillae (with respect to systemic plasma) even during excretion of hypotonic urine, together with a 7.6% vol of distribution of PAH in the papillae, indicates that final urine occupies only a small fraction of the renal papillary mass. Except for differences in location of peak concentrations, profiles of sodium and urea roughly paralleled those of total solute under all conditions. Decreases in papillary concentrations of sodium, induced by solute loading, paralleled those of osmolality in all cases. Decreases in papillary urea paralleled those of total solute (and Na) during loading in hydropenic dogs, but not in D.I. dogs. In the latter, concentration of papillary urea remained essentially fixed while those of Na and total solute decreased. In contrast to tissue concentrations of sodium and urea those of potassium increased in going from cortex to papilla under all conditions. The significance of these findings is discussed.
Osmotic properties of isolated turtle bladder
Authors: Brodsky William A. , Schilb Theodore P.
Published: December 2017

Variations in the composition of mucosal fluid induced reproducible changes of transport rates of water and salt across the isolated bladder wall of Pseudemys turtles. The bladders, removed from three different sets of turtles, were mounted in the form of sacs, and incubated so that the serosal surfaces were bathed by oxygenated Ringer solution in all cases. Set 1. Increasing chloride concentration of isoosmotic mucosal fluid from 0 to 110 mEq/liter resulted in increasing rates of water and salt loss. Rate of weight loss vs. mucosal chloride concentration yielded a Michaelis pattern with an apparent Km of 13 mEq/liter. Set 2. When mucosal solutions were pure sucrose, the rate of weight loss increased in a curvilinear manner with increasing gradients of osmotic activity across bladders. The nonlinear pattern was ascribed to observed changes in dimensions of the bladder wall and consequently to changes of concentration profiles in boundary layer fluids in the bladder. Set 3. When mucosal fluids were pure NaCl, the rate of weight loss vs. mucosal osmotic activity followed the pattern predicted from simple addition of water flows in sets 1 and 2. This, together with the observed independence between salt and water movement, indicated that the two forces imposed (transbladder osmotic gradient and salt pumping) act additively to induce transbladder movement of water.
Deoxycorticosterone-induced alkalosis in dogs
Authors: Roth Daniel G. , Gamble James L.
Published: December 2017

Metabolic alkalosis was produced with daily injections of deoxycorticosterone acetate (DCA) in eight dogs subsisting on diets deficient in potassium. In every case recovery from alkalosis was obtained within 5 days after discontinuing the hormone and without resupplying potassium. Diets low in potassium and high in sodium did not produce alkalosis without administration of the hormone nor did such diets prevent recovery from alkalosis after withdrawal of the hormone. Variations in the intake of sodium and potassium did, however, serve to modify the severity of DCA-induced alkalosis. In a study using four dogs, the increments in concentrations of bicarbonate in the plasma amounted to 2.6–3.7 mEq/liter when the animals were eating a normal diet, 5.7–10.4 when on a diet low in potassium, and 0.4–2.4 mEq/liter when both sodium and potassium were restricted.
Myocardial reactive hyperemia in the unanesthetized dog
Authors: Olsson Ray A. , Gregg Donald E.
Published: December 2017

Studies of myocardial reactive hyperemia in dogs 5–24 days after the implantation of electromagnetic flowmeters on coronary artery branches reveal that the duration of occlusion and the control flow rate are independent determinants of the volume of reactive hyperemia flow. Flow debt is almost always overpaid, the average figure being 500 ± 200%. Phasic coronary flow curves show an increase in both systolic and diastolic flow during reactive hyperemia, the increase in systolic flow being due in part to decreased myocardial contractility. Myocardial reactive hyperemia is thought to be due to the accumulation of vasodilator metabolites during the period of coronary occlusion.
Eructation, regurgitation, and reticuloruminal contraction in the American bison
Authors: Dziuk H. E.
Published: December 2017

Simultaneous pressure changes in four compartments of the reticulorumen of two young, female bison prepared with rumen fistulas were recorded during eating, ruminating, resting, and insufflation with nitrogen gas. Frequency, magnitude, and duration of contractions were measured in a series of 26 experiments during which the bison were tied in a stanchion. From these measurements it was concluded that reticuloruminal motility of American bison is similar to that of domestic cattle. Eructation occurred almost always during contraction of the posterior dorsal blind and dorsal sacs of the rumen. The frequency of eructation was similar to that which was reported previously in cattle and white-tailed deer. During rumination there was an extra reticular contraction during which regurgitation occurred.
Comparative physiology of intestinal taurocholate transport
Authors: Glasser James E. , Weiner I. M. , Lack Leon
Published: December 2017

Active transport of sodium taurocholate was demonstrated in the following species: albino mouse, golden hamster, squirrel monkey, king pigeon, and Leghorn chicken. The criterion for active transport was the ability of everted gut sacs to establish serosal: mucosal concentration gradients greater than unity In all cases, this activity was limited to the distal half of the small intestine. 2,4-Dinitrophenol inhibited taurocholate transport. These results are similar to those previously reported for tissue from rats and guinea pigs. In vivo studies were performed by introducing solutions of radioactive taurocholate into tied-off portions of the small intestine of anesthetized animals and determining the rate of appearance of the radioactivity in the bile collected from the common duct. The following species were studied: white rat, mongrel dog, spider monkey, and rabbit. In all cases the major transport activity was in the ileum.
Antihemophilic factor levels in bleeder swine following infusions of plasma and serum
Authors: Muhrer Merle E. , Lechler Eckhard , Cornell Creighton N. , Kirkland John L.
Published: December 2017

Swine with a hemophilia-like disease characterized by a long bleeding time and low antihemophilic factor (AHF, factor VIII) level were infused with porcine plasma and porcine serum. Unlike the response of classical hemophiliacs, but similar to that of patients with von Willebrand's disease, the initial postinfusion levels of AHF were sustained with some fluctuation for 24 hr. Serum infusion resulted in a delayed increase in AHF which reached a maximum concentration between the 12th and 24th hr after infusion. Within 75 hr the effects of both the plasma and serum infusions had vanished. No correction of the prolonged bleeding times was observed following the infusions. The AHF levels encountered after the infusion of plasma and serum cannot be accounted for by the AHF activity contained in the infused materials; new AHF synthesis or AHF release from storage are suggested as possible mechanisms.
Sulfobromophthalein sodium (BSP) conjugation and excretion in neonatal guinea pigs
Authors: Goldstein Joe , Schenker Steven , Combes Burton
Published: December 2017

The proportion of injected unconjugated and conjugated S35-labeled BSP excreted into bile in 1 hr was determined in neonatal guinea pigs at various ages after birth, and compared to values obtained in adult animals receiving comparable weight-adjusted doses of the respective compounds. Injected conjugated BSP was excreted into bile as readily in newborn guinea pigs 1 day of age, and older, as in adult animals. By contrast unconjugated BSP was excreted into bile more slowly in 1-day-old guinea pigs than in adults. Excretion of administered unconjugated dye reached adult levels between 5 and 12 days postpartum. Since unconjugated BSP is taken up by the liver at least as readily as conjugated BSP, if not more so, these data indicate that impaired conjugation of dye accounts for slower BSP delivery into bile in neonatal guinea pigs. This conclusion is further supported by the observations that both the enzyme that catalyzes BSP conjugation and glutathione, which is the substrate for conjugation, are decreased in livers of newborn animals.
Blockage of milk removal in the cat by periventricular diencephalic lesions
Authors: Beyer Carlos , Mena Flavio
Published: December 2017

Electrolytic lesions were placed in several structures of the CNS in lactating cats. Lesions in the periventricular region of the caudal hypothalamus resulted in stoppage of established lactation. This effect was due to failure of milk removal. Oxytocin when administered from the 1st postoperative day permitted lactation to continue, though at a subnormal level. The results suggest that through the periventricular diencephalic region course afferent fibers to the neurohypophysis which are involved in the oxytocin reflex release induced by suckling.
Relationship between water and food ingestion in the rat
Authors: Cizek L. J. , Nocenti M. R.
Published: December 2017

Daily observations for 3 months on the ad libitum water-to-food-intake relationship were made on young Sherman male and female rats subsisting on a diet of constant composition, with particular attention being given to the influence on this relationship of handling, weight, and sex. The 1st-week values for water intake in rats not handled prior to experimentation were always higher than subsequent trends and higher than those for previously handled rats. Though water intake increased as body weight increased, this dependence was slight (+.03–.05 ml/g increase in body wt) as contrasted to its dependence upon food intake (+.75 ml/g increase in food ingested). Since the body weight increased faster than the increase in food, the portion of water related to body weight comprised the greater fraction of the total daily water intake. While both absolute intakes continued to increase with time, water intake increased at a greater rate than food ingestion. Thus, the water-to-food ratio gradually increased. These findings obtained for both sexes.
Effect of maturation on hepatic adenosine triphosphate
Authors: Schenker Steven , O'Donnell James F.
Published: December 2017

Inasmuch as there are no quantitative data as to adenosine triphosphate (ATP) concentration in fetal and neonatal liver, a method for estimating the nucleotide in developing animals was devised and validated and the results obtained are reported here. The hepatic ATP levels, means ± sd, of fetal, one-day-old, nonpregnant adult, and pregnant guinea pigs were, respectively, 19.25 ± 3.36, 24.67 ± 3.90, 23.83 ± 2.98, and 26.12 ± 4.05 µmoles/g liver protein. In comparable groups of rats, which mature less rapidly, the values for ATP were 28.40 ± 3.24, 30.24 ± 2.72, 23.34 ± 2.17, and 22.62 ± 3.24 µmoles/g liver protein. It is concluded that 1) hepatic ATP concentration is specific for a species and does not appear to correlate primarily with its maturity, and 2) the levels of ATP in fetal and neonatal guinea pigs and rats are sufficiently similar to those in adult animals as not to be likely rate-limiting factors for hepatic ATP-dependent metabolic processes.
Antagonism of the inotropic action of ouabain by aldosterone
Authors: Lefer Allan M. , Sayers George
Published: December 2017

Aldosterone (3.3 x 10–8 to 10–7 m) exerted a small positive inotropic effect on cat Langendorff heart preparations depressed by pentobarbital and on cat papillary muscles depressed by low calcium. Equimolar concentrations of ouabain exerted a much greater inotropic effect in both preparations compared to aldosterone. Aldosterone (3.3 x 10–8 to 10–7 m) antagonized both the positive inotropic effect of cardiotonic concentrations and the bradycardia and cardiac arrest of toxic concentrations of ouabain. Cortisol (10–7 to 10–5 m) did not antagonize the effects of ouabain. Addition of aldosterone 20 min prior to the ouabain exerted maximal inhibition. Simultaneous aldosterone and ouabain addition resulted in a lesser degree of inhibition. Addition of aldosterone at the peak of the ouabain effect did not influence the subsequent course of the ouabain-induced inotropic effect.
Influence of adrenal cortex on body water distribution in rats
Authors: Moses Arnold M.
Published: December 2017

Body water distribution was determined in rats by the dilution of serum albumin-I131 and Br82 and by desiccation. Methylprednisolone (MP) increased the plasma and intracellular compartments and decreased the interstitial volume in intact hydrated rats. The body water moved in the opposite direction in the adrenalectomized, salt-maintained rats, and MP prevented this movement in terms of intracellular and interstitial volumes. Adrenalectomized rats which were salt depleted had an increased intracellular volume with water coming from both extracellular compartments, and MP had no effect in this group. The effect of deoxycorticosterone acetate was to increase plasma volume in the intact hydrated and in both adrenalectomized groups. The relationship between these changes in body water distribution, hematocrit, and plasma osmolality and sodium concentrations has been discussed.
Cyclic variations in hypothalamic temperature in unanesthetized rats
Authors: Abrams Robert , Hammel H. T.
Published: December 2017

Male and female rats, equipped with stainless steel re-entrant tubes implanted in the brain adjacent to one preoptic area, were placed in cages with accessible activity wheels. Brain temperatures were recorded continuously for periods up to 48 hr by means of thermocouples inserted into the tubes. The activities of running, feeding, and drinking were recorded simultaneously. About 90% of feeding and drinking activity occurred irregularly during three to nine periods of running activity at night. Active periods at night were associated with brain temperatures 1.0–2.5 C higher than inactive periods during the night or day. Moderate restraint with absence of food abolished these cyclic temperature variations whereas absence of food alone did not. During the night of estrus (9 pm–3 am), marked increases in activity frequently were associated with elevated mean preoptic temperatures.
Circulation of sympathectomized dogs under pentobarbital anesthesia
Authors: Chien Shu , Usami Shunichi
Published: December 2017

In sympathectomized-splenectomized dogs under pentobarbital anesthesia, the total blood volume averaged 78 ml/kg, with 20% in the splanchnic circulation and 28% in the central blood volume. These values are almost the same as those found in the splenectomized (control) dogs with the sympathetic system intact. The over-all and the splanchnic Fcells factors are also not significantly different between these two groups. The sympathectomized animals had lower arterial pressure, cardiac output, and splanchnic blood flow, but the resistances calculated for the total and the splanchnic circulations were not significantly different from those of the control dogs. The mean circulation times for the total, the central, and the splanchnic circulations were all longer in the sympathectomized dogs. The data indicate that, under pentobarbital anesthesia, sympathectomized dogs are characterized by slower blood flows without any significant changes in either the blood volume or vascular resistance.
Arterial blood gases of the domestic hen
Authors: Chiodi Hugo , Terman James W.
Published: December 2017

Individual blood samples were collected anaerobically from the brachial arteries of adult White Rock hens and were analyzed for Po2, Pco2, pH, oxygen content and capacity, and CO2 content and capacity. A dissociation curve was constructed from data on equilibration of pooled venous blood. The average arterial oxygen saturation was 90%, the Pco2 was about 32 mm Hg, the Po2 was between 94 and 99 mm Hg, and the pH averaged 7.49. The dissociation curve, as has been shown before, was shifted to the right of most homeothermic species.
Variations in intrauterine pH within a circadian rhythm (Gallus domesticus)
Authors: Winget C. M. , Mepham C. A. , Averkin E. G.
Published: December 2017

The intrauterine pH of the sexually mature bird appears to fluctuate diurnally. The changes in pH during mineralization would suggest a more complex mechanism responsible for the movement of calcium from the plasma to the uterus. The increase in intrauterine pH during the period of active salt and water transport may indicate pH is important in this mechanism. The Fourier-series, periodogram, and correlogram methods all indicate that intrauterine pH is cyclic. Furthermore, the correlogram suggests that the cycle is endodiurnal.
Effect of dinitrophenol on potential, resistance, and H+ rate of frog stomach
Authors: Rehm Warren S. , Lefevre Marian E.
Published: December 2017

Gastric mucosae were mounted between chambers, some with Cl– bathing solutions and some with Cl–-free bathing solutions. The effect of 2,4-dinitrophenol (DNP) was determined on the potential difference (PD), resistance, and H+ secretory rate. In Cl– experiments, the H+ rate was depressed to low levels without a marked decrease in the PD, and the PD did not vary linearly with the H+ rate. Neither ATP (6 mm) nor voltage clamping (nutrient + 150 mv) restored H+ secretion. The PD is inverted in Cl–-free solutions (nutrient is negative), and under these conditions DNP produced a decrease in the H+ rate which varied linearly with the decrease in the absolute magnitude of the PD. An analysis of this latter finding, on the basis of the separate-site theory of gastric HCl formation, revealed that during inhibition of H+ secretion only the electrogenic H+ mechanism is affected; the parameters of the return circuit within the mucosa are not changed. Under Cl–-free conditions the resistance and emf of the H+ mechanism were estimated; the resistance ranged from 571 to 1,350 ohm/cm2, and the emf from 33 to 56 mv.
Respiratory and blood pressure responses to stimulation of peripheral afferent nerves
Authors: Katz S. , Perryman J. H.
Published: December 2017

Experiments on cats anesthetized with pentobarbital sodium indicate that a change in the frequency of peripheral nerve stimulation will alter the direction of the blood pressure and respiratory response only after a certain intensity of stimulation is attained. Low voltage-high frequency (1–3 v, 60/sec), high voltage-low frequency (15 v, 10/sec) and low voltage-low frequency stimulation of the tibial and/or peroneal nerves initially produces a decrease in blood pressure (20–50 mm Hg) and a decrease in respiratory minute volume (13–92%). However, high voltage-high frequency stimulation generally produces an increase in blood pressure of 10–65 mm Hg and an 8–14% increase in minute volume. In decerebrate cats, low-voltage, high-frequency as well as high-voltage, high-frequency stimulation of the tibial nerve results in an increase in blood pressure, minute volume, and/or rate and amplitude of phrenic nerve discharge. Frequency and intensity are therefore interrelated. Anatomical specificity of limb peripheral nerve fibers into pressor and depressor afferents is not substantiated.
Interrelation of potassium and hydrogen ion gradients in metabolic alkalosis
Authors: Grantham Jared J. , Schloerb Paul R.
Published: December 2017

To study the interrelationships of potassium and hydrogen ion intra- and extracellularly, as an extension of previous investigations on gastric alkalosis, metabolic alkalosis was produced in dogs by dietary K depletion, NaHCO3 loading, and deoxycorticosterone administration, with and without chloride depletion. Analysis of skeletal muscle and measurement of intracellular pH confirmed the development of cellular K depletion, with increases of intracellular sodium and hydrogen ion associated with extracellular alkalosis and hypokalemia. These changes were not influenced by concomitant dietary chloride restriction. The intracellular K concentration was linearly and inversely related to the intra-extracellular hydrogen ion gradient. The intra-extracellular K gradient was about 10 times greater than the corresponding hydrogen ion gradient. These respective gradients were linearly related, in this proportion, over the range of K depletion studied in this type of metabolic alkalosis as well as that resulting from gastric juice loss. Deviation from this relationship occurred only with the most severe K depletion. These experimental observations demonstrate in vivo that the potassium and hydrogen ion gradients change in the same direction and are nearly constantly related in at least two types of metabolic alkalosis.
Intrarenal distribution of ammonia during diuresis and antidiuresis
Authors: Robinson Roscoe R. , Owen Edward E.
Published: December 2017

The intrarenal distribution of ammonia was evaluated in the dog during antidiuresis and osmotic (mannitol) diuresis at various levels of urine pH. During antidiuresis, the concentration of ammonia in renal tissue water rose progressively from the cortex to the tip of the papilla. In contrast, the corticomedullary ammonia gradient was completely obliterated by osmotic diuresis. In both experimental groups, a close relationship was observed between urine pH and the logarithm of the ratio between the urine and papillary concentrations of ammonia. The data are compatible with a proposal that a medullary countercurrent exchange system is responsible for medullary ammonia accumulation, and that diffusion equilibrium exists between the pNH3 of loop of Henle fluid, vasa recta blood, and collecting duct fluid.
Salivary response to stimulation of gastric branches of vagus nerve
Authors: Hockman Charles H. , Hagstrom Earl C. , Hoff Ebbe C.
Published: December 2017

In adult cats anesthetized with ether and immobilized with Flaxedil, submaxillary salivation was elicited following electrical stimulation of the central cut ends of the dorsal and ventral gastric branches of the vagus nerve. This response was abolished when the lingual nerve was severed above the terminal branching of the chorda tympani. Ipsilateral or contralateral section of the vagus nerve in the neck had no effect on the salivary response; however, it disappeared completely when the vagi were cut bilaterally. This shows that the visceral afferents mediating this response, from either gastric branch of the vagus, travel centrally in both vagi. These studies demonstrate a feedback circuit from the stomach to the salivary glands.
Mechanism of renal excretion of methylurea and acetamide in the dog
Authors: Rabinowitz Lawrence
Published: December 2017

The renal excretion of methylurea, acetamide, and urea was studied in anesthetized dogs during a graded osmotic diuresis produced by infusion of mannitol, urea, methylurea, or acetamide. Within the urine-to-plasma inulin range of 3–300, the clearances of these compounds relative to the inulin clearance were less than 1.0 while their urine-to-plasma ratios were greater than 1.0. For all compounds the urine-to-plasma ratios and the amount reabsorbed were directly related to water reabsorption. No dependence of reabsorption on filtered load and no transport maxima at high filtered loads were observed. These results suggest reabsorption of all three compounds by passive transport and indicate the absence of a quantitatively appreciable active secretion or reabsorption.
Effect of insulin on glucose metabolism in the dog after portacaval transposition
Authors: Starzl Thomas E. , Scanlan William A. , Thornton Fred H. , Wendel Robert M. , Stearn Burton , Lazarus Robert E. , McAllister William , Shoemaker William C.
Published: December 2017

The effect of insulin on hepatic glucose metabolism was studied by a multiple-catheter technique in unanesthetized dogs with Eck fistula and with portacaval transposition. With the latter preparation, blood entering and leaving the liver was sampled from peripherally inserted catheters. In the unanesthetized Eck-fistula animals, insulin infusion produced a decrease in the hepatic glucose output. In the dogs with portacaval transposition, a constant infusion of insulin was given alternately by systemic and by intraportal routes. There was no significant difference between the effects of insulin administered by the two routes. During insulin infusion, glucose concentration differences across the liver were reduced, hepatic plasma flow was transiently elevated, and hepatic glucose output was decreased. After discontinuance of insulin, there was a transient rise of hepatic glucose output to above control values.
Response of resistance and capacitance vessels to central nervous system stimulation
Authors: Baum Thomas , Hosko Michael J.
Published: December 2017

Responses of precapillary and postcapillary vessels, i.e., resistance and capacitance vessels, to electrical stimulation of the central nervous system of the cat were investigated. The hindquarters were perfused at constant flow, and changes in the tone of the resistance and capacitance vessels were indicated by changes in perfusion pressure and hindquarters volume, respectively. The hypothalamus, midbrain reticular formation, medulla, and lumbar sympathetic chains were stimulated at various voltages and frequencies. The most consistent finding was that changes in perfusion pressure were accompanied by oppositely directed changes in hindquarters volume. This was the case regardless of whether a pressor or depressor response was obtained and regardless of the central area stimulated. Stimulation of pressor sites frequently caused biphasic responses in perfusion pressure and volume. Maximal effects in both perfusion pressure and volume were usually produced by the same frequencies of stimulation. No central areas were found which predominantly and consistently affected perfusion pressure in preference to volume or vice versa. It is concluded that veins as well as arteries respond actively to stimulation of the central nervous system.
Contribution of the proximal tubule to urinary ammonia excretion by the dog
Authors: Clapp James R. , Owen Edward E. , Robinson Roscoe R.
Published: December 2017

Measurements of ammonia concentration were performed on 48 samples of proximal tubular fluid from antidiuretic dogs during normal acid-base balance, and acute or chronic ammonium chloride acidosis. Measurable concentrations of ammonia (>0.3 mmoles/liter) were not detectable in proximal fluid during either normal acid-base balance or acute ammonium chloride acidosis. However, in both conditions, an ammonia concentration in proximal fluid of less than 0.3 mmoles/liter could still have accounted for a large percentage of urinary ammonia. For this reason, the present data can neither confirm nor deny the existence of ammonia addition to proximal tubular fluid during normal acid-base balance and acute metabolic acidosis. In contrast, chronic metabolic acidosis was accompanied by the definite appearance of ammonia in proximal fluid, its concentration averaging 0.82 ± .32 mmoles/liter. This observation demonstrates clearly that net ammonia addition can be observed along the proximal tubule under certain circumstances. It suggests further that the proximal tubule also contributes to the adaptive rise of urinary ammonia excretion during chronic acidosis.
Mesencephalic hemisection in the primate
Authors: Mettler Fred A.
Published: December 2017

Relatively little information is available about the subacute and chronic condition of hemidecerebrate monkeys. The present communication deals, not with ablations of one-half of the supratentorial neuraxis, but with the effects of four different types of mesencephalic hemisections—cuts above and below the tectum, and cuts passing through the rostral and caudal parts of the magnocellular part of the red nucleus. None of these hemisections produced extensor rigidity on either side of the body. Rigidity, in the sense of resistance to passive movement, was only encountered as a flexor phenomenon. This appeared contralaterally when a high mesencephalic hemisection passed through the rostral part of the red nucleus. Examination of the evidence seems to suggest that in order for such a phenomenon to appear a subthalamically crossing tegmental mechanism needs to be severed in addition to the projection fibers in the pes pedunculi (which ultimately cross in the medulla). The tegmental crossing mechanism seems to exert a flexor inhibitory effect, in contrast to the extensor inhibitory influence which originates in the cortex.
Comparison of ruminoreticular motility patterns in cattle, sheep, and goats
Authors: Dziuk H. E. , McCauley E. H.
Published: December 2017

Simultaneous pressure changes in four compartments of the ruminoreticulum of trained, fistulated animals in each of three species of ruminants (cattle, sheep, and goats) were recorded under varying conditions of animal position and activity. Motility patterns in the three species were similar in most respects. They were different in the following ways: 1) Reticular motility in sheep and goats was characterized during rest by a biphasic contraction having less relaxation between the two phases than in cattle. During rumination the first of these phases was reduced in magnitude in sheep and goats. The reticular regurgitation contraction was of longer duration in sheep and goats. 2) The sequence of contractions in the rumen was more variable in cattle. 3) In sheep and goats the secondary caudal dorsal blind sac contraction was lower in magnitude and of shorter duration than the primary contraction, whereas in cattle the primary contraction was lower in magnitude and of shorter duration.
Mortality of germfree and conventional mice after thermal trauma
Authors: Markley Kehl , Smallman Elizabeth , Evans George , McDaniel Ernest
Published: December 2017

Germfree mice survive thermal trauma better than conventional mice. Mortality during the first 48 hr (shock mortality) after severe (95 C) and moderate (70 C) hot-water burns was significantly less in germfree animals than in conventional controls. Mortality after 48 hr (late mortality) was significantly reduced in germfree mice after a moderate burn. These experiments, together with the previous finding of gram-negative bacteria in the tissues of conventional burned mice, demonstrate that bacteria cause death in burned mice during the shock period as well as later.
Inhibition of active intestinal sugar transport by digitalis
Authors: Csáky T. Z. , Hara Yasuhiro
Published: December 2017

Ouabain or thevetin (10–5 m) inhibits the mucosal-to-serosal flux of 3-O-methylglucose only if present in the serosal but not if in the mucosal compartment. Digitoxin (10–4 m) inhibits if put in either compartment because it passes rapidly across the gut wall. The site of inhibition of the intestinal sugar pump thus is identical with that of the sodium pump. These findings support the theory that a functioning sodium pump is essential for the activation of the sugar pump in the small intestine, but they do not suggest a direct sodium effect on the sugar carrier.
Biological activity and fate of trace quantities of intravenous chromium (III) in the rat
Authors: Mertz Walter , Roginski Edward E. , Reba Richard C.
Published: December 2017

Complexes of trivalent chromium were injected intravenously into rats raised on a low-chromium diet. Two hours after the injection of submicrogram amounts, impaired glucose removal rates were increased to near-normal values. The response of epididymal adipose tissue to insulin in vitro, as measured by the production of C14O2 from labeled glucose, was significantly enhanced in the chromium-injected animals. The amounts required for these effects were approximately 1/10,000 of doses producing acute toxicity. The whole-body disappearance of intravenously injected submicrogram amounts of chromium could be described by a multiexponential expression. Compartmental-type analysis revealed at least three regression rates. These rates were unaffected by previous dietary history with regard to chromium and were independent of absolute amounts injected. Intestinal absorption of chromium ranged around a few percent of the dose, regardless of amount applied, and was independent of dietary history.
Effect of right ventricular hypertrophy on infundibular pressure gradients in dogs
Authors: Blundell Peter E. , Tobin John R. , Swan H. J. C.
Published: December 2017

Right ventricular hypertrophy was produced in normal dogs: in six by means of pressure overload (pulmonary artery banding) and in six by means of volume overload (systemic arteriovenous fistula). A greater degree of hypertrophy resulted from the latter procedure. Right ventricular hypertrophy due to chronic pressure overload causes a greater degree of infundibular constriction and much higher pressure gradient than in normal animals or in animals with volume overload. Infundibular pressure gradients associated with severe hypertrophy due to volume overload are not significantly greater than those observed in normal dogs. Infundibular gradients are dominantly related to narrowing of the outflow tract.
Udder blood flow in unanesthetized, lactating goats measured with nitrous oxide
Authors: Reynolds Monica
Published: December 2017

The N2O diffusion method, which was previously successfully adapted to the measurement of udder blood flow in anesthetized goats, was adapted to the same measurement in unanesthetized goats. For the N2O inhalation, masks were made for each goat, and each animal was trained to stand quietly while breathing through it. Sampling, analyses, and calculations were made as before. Seventeen determinations were made on seven goats in midlactation whose rates of milk secretion ranged from 29 to 147 ml/hr. The method appeared to be valid for the conscious animal. Udder blood flow ranged from 16 to 34 ml/min per 100 g udder tissue, and varied directly and linearly with the rate of milk secretion. These values agreed closely with those found by Linzell and by Rasmussen, each of whom used different in vivo methods on lactating goats. It is concluded that the N2O method can be used satisfactorily for the measurement of an average udder blood flow over a period of time of approximately 30 min in conscious, standing goats.
Effect of insulin on short-circuit current and sodium transport across toad urinary bladder
Authors: Herrera Francisco C.
Published: December 2017

The effect of insulin on short-circuit current and on the sodium transport system of the toad bladder has been examined. The rate coefficients for sodium movements across the mucosal and serosal barriers of the bladder epithelium were studied by observing the approach to a steady value of the flux of Na22 across the bladder. Insulin added to the solutions bathing both surfaces of the bladder causes a marked increase in short-circuit current. A smaller effect may also be elicited by adding the hormone to either the serosal or the mucosal bathing media. Insulin causes an important increase in the rate coefficient for sodium movement from the cells to the serosal solution with no significant change in the rate co-efficients for sodium movement across the mucosal surface of the epithelial cells. The results indicate that the action of insulin is the result of a stimulation of the active transport step at the serosal surface of the cells. Insulin does not appear to modify the permeability to sodium of the mucosal surface.
Effect of experimental anemias on cation concentrations of the erythrocytes of sheep
Authors: Blunt M. H. , Evans J. V.
Published: December 2017

The concentrations of potassium in the erythrocytes of sheep increased by a mean value of 30.9 mEq/liter of cells during experimental anemias. The concentrations of sodium decreased slightly, but the ratio of potassium to sodium was greater during anemia. These changes were demonstrated in sheep with genetically inherited low concentrations of potassium in erythrocytes as well as in those with high concentrations. The reticulocytes were separated from mature erythrocytes by centrifugation, and they contained about 101–128 mEq K+/liter of cells. Their mean corpuscular hemoglobin was about 20 µµg and their mean corpuscular volume about 100 µ3. The frequency curve of distribution according to volume was bimodal during anemia. It is concluded that the changes observed during anemia were the result of the addition of these reticulocytes to the total population and that either these cells were immature forms which had not undergone the full series of mitotic divisions, or alternatively they could be fetal-type cells.
Determinants of atrial contractile force in the intact heart
Authors: Williams John F. , Sonnenblick Edmund H. , Braunwald Eugene
Published: December 2017

Atrial contractile force was recorded in anesthetized open-chested dogs using a specially designed adjustable strain-gauge arch, linear over a wide range of forces. The shape of both resting and active atrial length-tension curves as well as the maximum force developed was similar to those described for the ventricle, after corrections for differences in muscle mass. Increasing heart rate by right atrial stimulation had no significant effect on atrial force. Isoproterenol, calcium, and acetylstrophanthidin each produced marked increases in the force of contraction. Sympathetic stimulation, produced by direct stellate stimulation or reflexly induced by carotid hypotension, increased atrial force, whereas direct vagal stimulation or vagal stimulation produced reflexly by balloon inflation in the thoracic aorta produced marked decreases in atrial force. Both atria were depressed more by direct stimulation of the right vagus nerve than of the left, and right atrial force was affected more than was left atrial force when either vagus nerve was stimulated.
Intracellular pH and intracellular buffering power of the cat brain
Authors: Roos Albert
Published: December 2017

In 49 cats the intracellular pH (pHi) of the brain was estimated from the distribution of 5,5-dimethyloxazolidine-2,4-dione-2-C14 (DMO) between brain, plasma, and CSF, at arterial pCO2 of 14.5–83.2 mm Hg. From six cats cortical biopsies were taken; in the remainder, brain DMO distribution was determined on postmortem samples from various brain regions, both white and gray. pHi of the samples was calculated, assuming extracellular space to be equal to either 3 or 12% of brain weight, and extracellular composition to be equal to composition of either arterial, cerebral venous, or mean capillary plasma, or CSF. Bicarbonate concentration of cell water and total CO2 concentration of brain were derived from the data. Results: 1) there were no significant regional differences in pHi; 2) when extracellular space was taken as 3% of brain weight, and its composition as equal to that of mean capillary plasma, the following relations were found: a) pHi = .494 pH arterial + 3.471, and thus pHi = 7.13 at arterial pH = 7.40 (and arterial pCO2 = 40); b) pHi = 7.83 – .42 log pCO2 tissue, and thus Δ log pCO2 tissue/Δ pHi = 2.38; c) Δ [HCO3]/ Δ pHi = 36.7 mEq/kg cell water; d) Δ [total CO2]/Δ pCO2 tissue = .33 ml/100 g cortical tissue in the pCO2 range of 30–50 mm Hg. The basic assumptions of the DMO method were critically examined. A general equation was developed which expresses the transmembrane steady-state distributions of the two members of the conjugate pair of a weak acid in terms of their relative permeabilities, intracellular and extracellular H+ ion concentrations, and membrane voltage. The equation was applied to the present experiments.
Exchange of nucleotide phosphates in normal and failing canine hearts
Authors: Fox Arthur C. , Reed George E.
Published: December 2017

Page 1383: Arthur C. Fox and George E. Reed. "Exchange of nucleotide phosphates in normal and failing canine hearts." Page 1383, column 2, line 10, "and increased production of ADP at the..." should read, "and decreased production of ADP at the..."
An effect of isoproterenol on rates of synthesis and secretion of testosterone
Authors: Eik-Nes K. B.
Published: December 2017

Page 1764: K. B. Eik-Nes. "An effect of isoproterenol on rates of synthesis and secretion of testosterone." Page 1768, Fig, 8, the label on the ordinate should read, "Testosterone µg/1O g testis tissue wet weight."
A Comparison of renin obtained from pregnant uterus and kidney of the dog
Authors: Carretero O. A. , Houle J. A.
Published: December 2017

Page 689: O. A. Carretero and J. A. Houle. "A comparison of renin obtained from pregnant uterus and kidney of the dog." Page 691: The Km values appearing in Table 1 and in the text on this page are in error due to the employment of the natural logarithm instead of log to the base 10 in the computer program. The corrected Km and sem values are: Km = 619 ± 66 for the kidney enzyme, and Km = 580 ± 54, for the uterine enzyme.
Total contents and net movements of magnesium in the rat uterus
Authors: Moawad A. H. , Daniel E. E.
Published: December 2017

Page 75: A. H. Moawad and E. E. Daniel. "Total contents and net movements of magnesium in the rat uterus." Page 80, column 2, line 44, involving the calculation of Vm the answer to the equation, –0.067 V, should read, "–0.012 V." Page 80, column 2, lines 49–54 should read, "The calculated magnesium equilibrum potential is less than the observed membrane potential, which is about 0.050 V. Therefore, some of the tissue magnesium may be excluded by an active transport process against an electrochemical gradient or by loose binding in the extracellular space."
Prolyl hydroxylase and collagen metabolism after experimental mycardial infarction
Authors: Judd JT , Wexler BC
Published: December 2017

Mature male Sprague-Dawley rats were subjected to an isoproterenol-induced myocardial infarction. Animals were sacrificed on a daily basis in order to assess the temporal changes in prolyl hydroxylase activity and collagen metabolism during the acute stages of myocardial necrosis and repair. Total myocardial hydroxyproline, as an indexof collagen content, increased promptly and markedly, beginning on day 4, and remained elevated thereafter. The incorporation of (14Cl)-proline into definitive hydroxyproline of mature collagen was also increased. The activity of the enzyme prolyl hydroxylase, which regulates the rate of conversion of proline to hydroxyproline in collagen, was elevated by day 2, remained high through day4, and then declined to a relatively constant but still slightly elevated level throughout the period of repair. It is believed that changes in these parameters of collagen metabolism reflect changes in myocardial fibroblastic cell and ground substance pertinent to fundamental aspects of repair of the injuried myocardium.