bluuebunny/crossref_metadata_2025 huggingface dataset:
Nerve regeneration in replanted canine limbs
Authors: Mayer Richard F. , Eiken Oddvar , Nabseth Donald C.
Published: December 2017

The conduction velocities in regenerating common peroneal and tibial nerves were determined in the replanted hind limbs of 12 dogs examined 3–29 months following operation. The velocities in the fastest nerve fibers (max. diam. 7–11 µ) were approximately 50% less than the velocities in the fastest fibers in nonoperated (control) limbs (max. diam. 15–20 µ). This degree of nerve regeneration was sufficient to provide useful extremities in these animals. There was persistent slowing of conduction velocity proximal to the site of transection, which was associated with a decrease in the number of large fibers. Conduction velocity was decreased distally in replanted limbs consistent with the process of centrifugal nerve regeneration. The velocity as well as the diameter of the nerve fibers did not return to normal even 29 months after replantation and was less than that reported after section and suture. This difference was probably related to the additional surgical trauma and temporary ischemia associated with amputation and replantation of the limb.
Differential effects of heat on splenic and renal vascular beds
Authors: Gillenwater Jay Y. , Frohlich Edward D. , Keller Allen D.
Published: December 2017

The effects on vascular resistance of increasing blood temperature, from hypothermic to hyperthermic levels, were evaluated on denervated perfused spleens and kidneys in the dog. Temperature of the perfusate (blood) was increased for variable intervals of time from the hypothermic level of 32 C to the hyperthermic level of 42 C. The calculated resistance in the splenic vascular bed increased, whereas the resistance decreased in the renal vascular bed. It is concluded that heat has a differential effect in the splenic and renal vascular bed, causing vasoconstriction in the spleen and vasodilation in the kidney.
Pulsatile pressures in the microcirculation of frog's mesentery
Authors: Wiederhielm Curt A. , Woodbury J. Walter , Kirk Samuel , Rushmer Robert F.
Published: December 2017

Pressure within the microvascular bed of the frog mesentery has been recorded continuously with micropressure transducers which have tip diameters ranging between 0.5–5 µ. The mean values of pressure are in the range of those previously reported. The waveform of the pressure pulses in arterioles and metarterioles closely resembles that in the larger arteries. This observation signifies that the vascular walls are considerably stiffer than is generally believed. The stiffness is probably attributable to the constricted vascular smooth muscle.
Effect of volume and volume history of the lungs on pulmonary shunt flow
Authors: Anthonisen Nicholas R.
Published: December 2017

Relative pulmonary shunt flow (Qs/Qt), was measured in denitrogenated open-chested cats during apnea over the full range of lung volumes. The particular lung volume and transpulmonary pressure were also measured. When completely collapsed lungs were inflated, Qs/Qt decreased sharply to 3% at total lung capacity (TLC). During deflation from TLC Qs/Qt was insensitive to changes in lung volume. Qs/Qt remained low during reinflation after deflation from TLC. These changes in shunt flow can be interpreted as due to either recruitment or collapse of gas exchange units during lung volume change. It appears that completely collapsed lungs inflate very unevenly but that deflation from TLC proceeds remarkably evenly. Reinflation after deflation from TLC also seems to proceed evenly, and the manifest pressure-volume hysteresis is most likely due to hysteresis of the surface-active properties of the alveolar lining material.
Relationship of maximal tubular phosphate reabsorption to filtration rate in the dog
Authors: Hellman Dorothea , Baird H. Robert , Bartter Frederic C.
Published: December 2017

A maximal renal tubular rate of reabsorption of phosphate (Tmp) has been demonstrated in the normal dog. In the dog, as in the man, considerable variability in the Tmp often occurs. While some of this variability remains unexplained, a direct relationship between glomerular filtration rate (GFR) and Tmp can be demonstrated when the GFR is varied over a wide range. This relationship suggests that glomerular intermittency may exist in the dog.
Myocardial developed tension and oxygen supply
Authors: Lentini Eugene A.
Published: December 2017

The isometric developed tension of rat's trabecula carnea was recorded, in vitro. The magnitude of the developed tension was observed to be directly a function of the partial pressure of oxygen in the aerating mixture. This activity reached a maximum at pO2 values of 700 mm Hg. Fluctuations in the developed tension were noted during the 1st hr of the experiment; insignificant changes with noted exceptions occurred during the 2nd and 3rd hr. The data indicate that the mechanical response of the tissue is a function of both duration of the experiment and aerating gas mixture. The diflusion coefficient ( D') of oxygen through the preparation was calculated. The results indicate that the D' value for heart muscle may be larger than that of skeletal muscle as determined by Krogh.
Distribution of copper in the rat
Authors: Owen Charles A.
Published: December 2017

The concentrations of copper in organs of white male rats were measured. Highest concentrations were in the kidney (5.1 µg/g wet wt.), liver (4.4), heart (4.5), and pituitary (about 5). Hair contained about 30 µg/g. From the weights of the organs and their copper concentrations, the total copper contents of the organs and of the whole rat were calculated. The whole rat (250 g) contained slightly less than 0.5 mg, of which about half was in the skin and muscle. Balance studies indicated that approximately 300 µg of copper was excreted daily, almost exclusively in the feces. Relatively small amounts of copper were excreted in urine. When expressed as proportion of body weight, the weights of testes, pancreas, skin, and eyes were larger in the rat than in man, and adrenals, brain, and thyroid were considerably smaller.
Prolonged anoxic survival due to anoxia pre-exposure: brain ATP, lactate, and pyruvate
Authors: Dahl Nancy Ann , Balfour William M.
Published: December 2017

Rats subjected to a brief anoxia can survive go sec in a second anoxia, compared to a 60-sec survival time of control animals. Slower disappearance of ATP concentration in the brain during the second exposure indicates this longer survival is due to an altered cerebral energy metabolism. Initial cerebral ATP concentration is no higher in pre-exposed animals than in controls. When glycolysis is inhibited by iodoacetate before testing in anoxia, the advantage of pre-exposure disappears, suggesting the longer survival may be due to increased anacrobic glycolysis. Lactate accumulates faster during anoxia in the brains of pre-exposed animals than in controls, suggesting that increased anaerobic glycolysis is the cause of the prolonged survival. This effect is not due to increased cerebral glucose concentration. A possible reason for this increased glycolysis, and thus the prolonged survival, could be an increase of a compound, such as pyruvate, capable of oxidizing NADH. The initial pyruvate is higher in pre-exposed animals than in controls and injection of pyruvate increases the survival time slightly.
Hypertension caused by salt loading. II: Fluid volume and tissue pressure changes
Authors: Douglas Ben H. , Guyton Arthur C. , Langston Jimmy B. , Bishop Vernon S.
Published: December 2017

Experimental hypertension was produced in dogs by increasing their dietary intake of sodium chloride after removing approximately 70% of their renal tissue. The changes in mean arterial pressure, interstitial fluid pressure, blood volume, and sodium space were observed during the development and maintenance of the hypertension. During the periods of increased salt intake, the arterial pressure increased from a mean of 114.6 mm Hg to a mean of 150.6 mm Hg, and there were concomitant increases of 19.8% in blood volume, 16% in sodium space, and 4 cm H2O in interstitial fluid pressure. However, the increases in all the paramteers studied except arterial pressure were transient. The blood volume remained elevated above control values for a longer period of time than the sodium space and interstitial fluid pressure, but it reapproached normal after approximately 16–20 days.
Smooth and cardiac muscle in states of strong internal crosslinking and high permeability
Authors: Bozler Emil
Published: December 2017

In 2- to 4-mm solutions of MgCl2 and BaCl2 stiffness and opacity of the frog's stomach muscle increased strongly. These effects were completed within about 10 min. They indicate a strong increase in internal crosslinking. In dilute solutions of CaCl2 and BaCl2, the muscles gave responses to stretching although they were electrically inexcitable and did not contract when depolarized by K solutions. Weak stretch responses were also obtained in isoosmotic solutions of K2SO4. Thus depolarization is not a necessary step in the responses to stretch. If muscles, after being immersed in 2–4 mm MgCl2 or BaCl2, were returned to Ringer's solution, excitability and even spontaneous activity could be restored, although permeability to electrolytes and nonelectrolytes was greatly increased. Preparations of the frog's ventricle gave similar results. Implications of these findings for presently accepted views on the nature of excitatory processes are pointed out.
Effects of calcium on isolated mammalian heart
Authors: Seifen Ernst , Flacke Werner , Alper Milton H.
Published: December 2017

The effect of calcium on heart rate, A-V conduction, and contractility was studied in the dog's heart-lung preparation. Normal plasma calcium concentration was 2.71 ± 0.20 mm (N = 25). Heart rate was increased by calcium in the range from 1.6 to 14.0 mm and fell at still higher levels. A-V conduction time was shortest at calcium concentration slightly above normal, and decreased at higher as well as lower concentrations. At levels above 17 mm conduction block, fibrillation or cardiac arrest, or both, occurred. Contractile force was markedly reduced at low calcium. Increase of calcium lowered ventricular filling pressure, increased the rate of tension development and of relaxation, and shortened duration of contraction. The effects of calcium were not altered by pretreatment with reserpine (2 x 0.5 mg/kg, s.c., given 48 and 24 hr prior to experiment) and were not influenced by atropine (2–5 mg). The effect of calcium on contractility was fully developed 100 sec after administration; the effect on sinoatrial rhythm was established only after 4.4 ± 0.54 min.
Circulating antidiuretic hormone in rats: effects of dietary electrolytes and protein
Authors: Little John B. , Radford Edward P.
Published: December 2017

Plasma antidiuretic activity, believed to be antidiuretic hormone (ADH), has been studied in undisturbed rats: 1) fed diets containing normal amounts of protein but varying concentrations of sodium and potassium salts; 2) fed high-protein diets with and without supplementary urea and NaCl; or 3) dehydrated for periods up to 3 days. Plasma ADH in control rats was generally below the assay sensitivity of 4 µU/ml. With 24 hr dehydration ADH averaged 6.8 µU/ml plasma, and after 48–72 hr dehydration, 18.1 µU/ml. Of animals fed 27% protein diets, only in those whose diet contained very high salt (6% NaCl) was the average ADH level significantly elevated (about 5.5 µU/ml) and considerable variation from animal to animal was observed. Rats fed high-protein diets showed a more consistent rise in circulating ADH (range 4–8 µU/ml); many were above 6 µU/ml, calculated to produce maximal antidiuresis in the rat. High plasma ADH in dehydrated rats, or in rats fed high-salt diets may be explained by changes in plasma osmolality. The mechanisms producing increased ADH with high-protein intake are less clear. The possible effect of chronically elevated endogenous ADH on the renal concentrating mechanism is briefly discussed.
Dual effects of saline loading on renal tubular sodium reabsorption in the dog
Authors: Stein Richard M. , Bercovitch D. Danny , Levitt Marvin F.
Published: December 2017

Saline (0.9–1.5%) was administered at increasing rates to hydropenic dogs. Constriction of one renal artery performed early in the course of the infusion and maintained thereafter produced unilateral reductions in glomerular filtration rate (GFR) up to 50%. Since GFR increased bilaterally, the filtered load obtained late in the infusion on the constricted side was often comparable to that noted earlier on the control side. At comparable filtered loads sodium reabsorption was approximately 15% lower, later in the infusion. It was proposed that a saline infusion, apart from its effects on filtered load, progressively inhibits sodium reabsorption by decreasing the percentage of the sodium load reabsorbed. These data virutally excluded a fixed transport maximum for sodium. On the basis of filtered sodium, Tch2o, Uosm, and solute excretion data it was suggested that during saline loading sodium reabsorption in the proximal tubule and ascending limb generally remains proportional to the filtered load while simultaneously there develops an inhibition in sodium reabsorption which may exert a major effect at a site distal to the ascending limb.
Body fluid and hematological changes in a poikilothermic animal on cold exposure
Authors: Deb Chandicharan , Boral Mohan Chand
Published: December 2017

Body fluid and hematological values were compared in the toad ( Bufo melanostictus), a poikilothermic animal, kept at 6 C for 48 hr, and in the same animal at 32 C. Exposure to cold caused a reduction in total body water but an increase in plasma volume. There was no significant difference in blood volume and thiocyanate space between the two groups. The red blood cell count in the control animals of this amphibian class was found to be markedly low compared to mammals, and a further reduction occurred on exposure to cold. No notable alteration could be observed in the hemoglobin levels and hematocrit values due to either difference in class of vertebrates or to temperature exposure.
Active and passive chloride movements across isolated amphibian skin
Authors: Zadunaisky José A. , De Fisch Felisa W.
Published: December 2017

Several aspects of chloride passage through isolated amphibian skin were studied. The chloride transport performed by the skin of the frog Leptodactylus ocellatus or the passive chloride fluxes observed in the skin of the toad Bufo arenarum Hensel are not affected by antidiuretic hormone. The chloride transport produces a negative potential and a short-circuit current in sodium-free solutions, though the unidirectional fluxes of chloride are greatly reduced under these conditions. The short-circuit current due to the chloride transport is smaller than the net chloride flux. It was found that this disagreement could be ascribed to a loss of sodium toward the inside from the sodium pool of the skin. Antidiuretic hormone did not affect the chloride current, nor the sodium loss from the skin. The isolated skin of the toad Bufo arenarum Hensel does not transport chloride ions. Thus the active transport of chloride observed in isolated skins of the frog Leptodactylus ocellatus does not depend on environmental conditions, since both animals live in the same surroundings.
Hormonal effects on lymphatic transport of interstitial albumin in the dog
Authors: Takeda Y.
Published: December 2017

Albumin-I131 was subcutaneously injected into dogs under control conditions and while receiving growth hormone, thyroxine, or cortisone, and measurements were made of the subcutaneous disappearance and the appearance of the radioactivity in the plasma. These data were then expressed by a two- or three-exponential equation, and the rate of decline (α) of the equation describing the subcutaneous radioactivity was taken as an indirect measure of lymph flow. Lymph flow thus measured was increased in dogs treated with growth hormone or thyroxine while markedly decreased in dogs receiving cortisone. In accordance with the increased lymph flow, the time required for the subcutaneous radioactivity to appear in the plasma was shorter in dogs treated with growth hormone or thyroxine, but it was again shorter in dogs treated with cortisone despite the decreased lymph flow. These findings and further mathematical analysis of the data led to the concept that under the influence of cortisone, the interstitial albumin bypasses, at some sites along the lymphatics, the normal paths of albumin transport.
Ionic fluxes of Rana pipiens stomach bathed by sulfate solutions
Authors: Kaneko-Mohammed Sachiko , Hogben C. Adrian M.
Published: December 2017

Efforts to understand the interdependence of the active transport of hydrogen and chloride ion by bathing gastric mucosae with sulfate-substituted salines have not led to agreement. For Rana pipiens, an independent hydrogen ion pump has been proposed, and an anion transporting system has been implicated in H+ transport by Rana catesbiana. This discrepancy prompted further study of the former gastric mucosa. The results show that the R. pipiens stomach does not actively transport SO4– and is able to secrete H+ without concomitant transport of anion. This is in agreement with the initial observation of Heinz and Durbin. Reversal of the spontaneous transepithelial potential upon exposure of the stomach to sulfate salines, however, is highly variable and in these experiments is attributed to a net transfer of Na+ from serosa to mucosa as well as to secretion of H+, not to the transport of the latter ion alone. For the gastric mucosa whose serosal aspect is bathed by sulfate saline, substitution of the mucosal fluid by an isoosmotic sucrose solution resulted in a reversible cessation of hydrogen ion secretion.
Effects of steroids on the course of hereditary muscular dystrophy in mice
Authors: Dowben Robert M. , Zuckerman Leon , Gordon Paul , Sniderman Stephen P.
Published: December 2017

Page 1049: Footnotes 3 and 4 for authors Paul Gordon and Stephen P. Sniderman, respectively, should be transposed to read, for Paul Gordon: Fellow of the MEDRA Foundation. Present address: Dept. of Pharmacology, Chicago Medical School, Chicago 12, Ill. For Stephen P. Sniderman: Trainee in Metabolism under National Institutes of Health Training Grant 2A-5071. Present address: University of Michigan Hospital, Ann Arbor, Mich.
Amount of albumin and its mixing rate in the dog
Authors: Huggins R. A. , Deavers S. , Smith E. L.
Published: December 2017

Data on rates of mixing of I131-tagged albumin between vascular and extravascular compartments indicate that albumin disappears from the plasma at three exponential rates. The first rapid rate changes to a slower rate at 8 hr and continues until mixing is complete between vascular-extravascular albumin, in approximately 3 days. The third rate is interpreted as the metabolism of albumin. The data suggest that the extravascular space has at least two compartments, one that exchanges albumin with plasma rapidly and the other slowly. At approximately 8 hr, equilibrium was reached between specific activity of plasma and lymph albumin; it was postulated that the rapidly mixing extravascular compartment may be associated with the large pore area of the liver. Total amount of albumin was 2.87 g/kg with a ratio of extra- to intravascular albumin of 1.22. The mean volume of distribution of albumin was 168.8 ml/kg (17% of body wt), with 50 ml/kg in the circulation, 15.3 ml/kg in the rapidly mixing, and 103.5 ml/kg in the slowly mixing compartments of extravascular spaces.
Histamine formation in the blood and bone marrow of the guinea pig
Authors: Aures Dorothea , Winqvist Gösta , Hansson Eskil
Published: December 2017

The histamine content and the histidine decarboxylase activity of bone marrow have been studied in guinea pigs treated with foreign protein. In some experiments the effect of 6-methylprednisolone also was observed. Treatment of guinea pigs with foreign protein resulted in a 10-fold increase of both histamine concentration and histidine decarboxylating activity in the blood and bone marrow. Histamine levels and histidine decarboxylating activity were related to the number of basophils. A fairly constant relationship was found between the histamine content and the enzyme activity per basophil. The findings suggest that histamine is formed and to a certain extent also stored in the basophilic leukocytes.
Gastric secretory response to graded insulin hypoglycemia
Authors: Davis Richard A. , Brooks Frank P. , Robert Cavett McN.
Published: December 2017

Variable dosages of intravenous insulin, <0.075 U/kg (range, 0.01– 0.06 U/kg), 0.075 U/kg, 0.1 U/kg, and 1.5 U/kg were used in 10 dogs fitted with a Thomas fistula. The course of insulin hypoglycemia was monitored continuously by the AutoAnalyzer and plasma steroid (hydrocortisone) levels were determined hourly after insulin. Total acid output during the 2nd and 3rd hr after 1.5 U/kg insulin was greater ( P < 0.01) than after 0.1 U/kg, but not during the initial hour. Minimal or no gastric secretion occurred with 0.075 U/kg insulin or less. Increase in flow of gastric contents occurred if blood sugar concentration was 40 mg/100 ml or less (potassium ferricyanide method). Rate of blood sugar and concentrations of less than 40 mg/100 ml were not correlated statistically with total acid output 30–60 min after insulin. In most experiments, increase in flow of gastric contents occurred simultaneously to or followed the lowest point reached by the blood sugar. Plasma hydrocortisone levels were highest with 1.5 U/kg insulin, and remained elevated up to 5 hr.
Cardiovascular responses to metabolic acidosis
Authors: Downing S. Evans , Talner Norman S. , Gardner Thomas H.
Published: December 2017

The performance of the left ventricle was examined in a feline preparation which allowed precise control of aortic pressure, cardiac output, heart rate, and temperature. The arterial pH, Po2, and Pco2 were continuously measured with a Jewett flow-through electrode assembly. Reduction of arterial pH from 7.45 to 6.80 by HCl or lactic acid infusion was associated with a minimal reduction or no change of left ventricular contractility as measured by the stroke volume or mean ejection rate for a given left ventricular end-diastolic pressure at a constant aortic pressure and heart rate. No evidence for a diminished positive inotropic response to norepinephrine was found. Simultaneous systemic and pulmonary pressure-flow curves demonstrated that metabolic acidosis caused a reduction of systemic vascular resistance and a concurrent increase of pulmonary vascular resistance.
Effect of glycogenolytic agents on phosphorylase activity of perfused rat liver
Authors: Levine Robert A.
Published: December 2017

The effect of glycogenolytic agents on phosphorylase activity has been studied in the isolated perfused rat liver. Evidence is presented showing that endoportal administration of 10–6m glucagon, 10–5 m epinephrine, and 10–3 M cyclic 3',5'-adenosine monophosphate (3',5'-AMP) induced glycogenolysis, hyperglycemia, and increase in liver phosphorylase activity, usually within 1 hr after the onset of infusion. ATP, 10–3m, also caused glycogenolysis, but the onset was slower than with the cyclic nucleotide, and phosphorylase activation was inconstant Hyperglycemic effects of these two adenine nucleotides were also demonstrated in intact rats. Anoxia and hypoxia caused substantial glycogenolysis but did not stimulate phosphorylase activity, implying that some other mechanism accounts for the glycogen breakdown induced by reduced oxygen tension. Glycogenolysis and phosphorylase activation were not produced by administration of 10–2 M 5'-AMP, 10–4 M isoproterenol, adrenocorticotrophic hormone, or insulin.
Effect of dietary zinc on metabolism of zinc 65 in hens
Authors: Kienholz E. W. , Sunde M. L. , Hoekstra W. G.
Published: December 2017

Hens fed zinc-deficient (10 ppm Zn) and zinc-supplemented (70 ppm) diets for 5 months were given zinc 65 intramuscularly, and fecal and egg radioactivity was followed for 70 days before the hens were sacrificed. Egg yolks accounted for nearly all of the total egg radioactivity. The low-zinc diet reduced fecal isotope loss to 60% of that observed for the high-zinc diet Fecal and egg-yolk excretion patterns of zinc 65 suggested that the pool of rapidly turning-over zinc which is the precursor for egg and fecal zinc was smaller and had a shorter turnover time in the zinc-deficient hens However, the size of the total body zinc pool was little affected by diet At 70 days after injection, zinc-deficient hens had about 30% as much radioactivity per unit of bone but about 150% as much radioactivity per unit of soft tissue as did the zinc-supplemented hens. These differences in zinc 65 distribution were of the same magnitude when expressed as counts per minute per milligram zinc.
Blood reservoirs in the splenectomized dog
Authors: Baker Carleton H.
Published: December 2017

Changes in plasma protein concentration, hematocrit, and red cells Cr51 concentration (count/min per ml blood) were determined following various procedures to acutely alter hemodynamics in an attempt to determine the presence of red cell or plasma reservoirs in splenectomized dogs. The cell reservoir index (percent change in hematocrit minus the percent change in count per minute per milliliter blood) increased significantly following procedures causing increased total peripheral resistance and arterial pressure. These procedures included epinephrine, angiotensin, and norepinephrine infusions as well as cold-pack applications. This was interpreted to be a shift of red cells out of reservoirs. Depressor procedures such as phentolamine followed by epinephrine infusion, isoproterenol, and acetylcholine caused no change in reservoir index. Histamine infusion caused a reduction in cell reservoir index. There was a shift of whole plasma from reservoirs into the active circulation following the infusion of epinephrine into animals previously administered phentolamine. The red cell reservoirs are believed to be generally distributed throughout the organism.
Antibody to antihemophilic factor and its lack of reaction with hemophilic plasma
Authors: McLester William D. , Wagner Robert H.
Published: December 2017

A partially purified preparation of canine antihemophilic factor was obtained utilizing amino acids as precipitating agents. This AHF preparation was used as the antigen in an immunologic investigation of canine hemophilia. Plasma from rabbits immunized with this preparation contained antibodies which inhibited the coagulation of normal canine plasma. The immune rabbit plasma inhibited AHF activity but had no measurable effect on any other procoagulant. Neither canine hemophilic plasma nor fractions prepared from canine hemophilic plasma contained an antigen capable of neutralizing the inhibitor (no cross-reacting material). The inhibitor titer was inversely proportional to the amount of added AHF in the form of a fraction of normal canine plasma. The inhibitor cross-reacted with human plasma AHF, but not with porcine, bovine, or rabbit AHF. The results of these studies are interpreted as providing further evidence that hemophilia, specifically canine hemophilia, is due to the failure of production of the antihemophilic factor.
Effects of protamine zinc insulin on chickens
Authors: Lepkovsky S. , Len R. , Koike T. , Bouthilet R.
Published: December 2017

The injection of protamine zinc insulin into laying hens caused hypoglycemia as it does in other animals. While it increased feed intake and body weight in other animals, it did the opposite in chickens: it decreased feed intake, body weight, and egg production. Damage to the central nervous system in some of the chickens was indicated by their behavior. It was tentatively concluded that the aphagia in chickens following injection with protamine zinc insulin was due to the apparent damage to the nervous system.
Effects of nutrition and photoperiod on reproductive physiology of Microtus montanus
Authors: Pinter Aelita J. , Negus Norman C.
Published: December 2017

A total of 140 pairs (one male, one female) of known-age virgin Microtus montanus was used in two experiments lasting 18 weeks each. Pairs were divided into two groups, one placed under 18 hr, the other under 6 hr of artificial illumination daily. Under each of the two photoperiods, half of the pairs received a dietary supplement of sprouted wheat every 3 days (G), the other half every 15 days (D). The G groups produced significantly more litters and offspring than did the D groups. Irrespective of diet, mean litter size was significantly larger under 18-hr than under 6-hr illumination. Any superiority in reproductive performance due to diet could be attributed solely to frequent (G) supplementation with sprouted wheat. "Plant estrogens" are tentatively postulated as the active principle. Diet and photoperiod interact in their influence on reproductive physiology (G-18 was the most productive group, D-6 the least productive).
Influence of the cardiac nerves on coronary resistance
Authors: Berne Robert M. , DeGeest Hilaire , Levy Matthew N.
Published: December 2017

During constant pressure perfusion of the left coronary artery, stimulation of the peripheral cervical vagi produced a small but definite increase in coronary blood flow (CBF) in paced and nonpaced beating hearts and in fibrillating hearts. In the latter preparations flow increment was associated with an increase in coronary sinus blood pO2 (CspO2), changes similar to those elicited by intracoronary administration of acetylcholine. During constant pressure perfusion of the left coronary artery in paced and nonpaced beating hearts and in fibrillating hearts, stimulation of the stellate ganglia produced an initial decrease and subsequent increase in CBF. The increase in flow was associated in time with a reduction in CspO2 in fibrillating hearts. The results obtained with stellate ganglion stimulation were reproduced by intracoronary administration of epinephrine. These observations indicate that the primary effect of vagus nerve stimulation on the coronary vasculature is vasodilation and that of stellate ganglion stimulation, constriction. The delayed increase in CBF seen with stellate ganglion stimulation is presumably secondary to the attending enhanced myocardial metabolic activity.
Electrical thrombosis of blood vessels: A voltage-dependent phenomenon
Authors: Lamb John C. , Isaacs James P. , Bloom Walter L. , Harmer Don S.
Published: December 2017

The in vitro coagulation of dog whole blood and the in vivo thrombosis of blood vessels by means of an electric current were found to be voltage-dependent phenomena. The critical potential difference below which they do not occur appears to be 2.0 v. Electrolytic decomposition potentials of several salt- and protein-containing solutions between smooth Pt electrodes were found to cluster between 2.0 and 2.3 v as determined by their voltage-current curves. Below 2.0 v whole blood was not found to deposit as a coagulum on the positive electrode even when the amount of charge allowed to flow was greater than that which caused coagulation at higher voltages. In vivo electrical thrombosis was found to have similar voltage dependence in femoral vein pairs in the dog. Those at 2.5 v thrombosed whereas those at 2.0 did not—even though the current was the same in each instance. Attention is called to the fact that a change in transmural potential cannot then be the initiating factor of "normal" thrombosis.
Analysis of electrolyte movement in thin Henle's loops of hamster papilla
Authors: Marsh Donald J. , Solomon Sidney
Published: December 2017

Saline solutions isolated between oil droplets within the lumen of thin limbs of Henle's loops remained at constant volume, while raffinose solutions underwent a continuous volume increase with time. After equilibrium, composition of the NaCl perfusates with respect to osmolality and Na and Cl concentrations became similar to that of vasa recta plasma. These results were identical for both ascending and descending limbs and suggest that neither segment transports salt actively. Descending limbs and vasa recta were isopotential under all conditions; the ascending limb during antidiuresis is 9 mv negative, the collecting ducts 17 mv negative. Ascending limb negativity was abolished by osmotic diuresis or stopped-flow microperfusion with saline. Measurement of ion concentrations showed that the ascending limb potential of antidiuresis is not a diffusion potential, and that its disappearance during osmotic diuresis is not due to the appearance of a diffusion potential of countersign. We suggest that the ascending limb potential is a streaming potential, but that the collecting duct potential reflects active ion transport.
Anomalous viscosity of human blood
Authors: Mayer George A.
Published: December 2017

The viscosity of human blood relative to distilled water observed in a capillary viscometer decreases with the length (in the range of 1.65– 10.5 cm) and increases with the reduction of the radius (in the range of .0106–.0217 cm) of the capillaries. No such changes are present when the flow rate of oils instead of water is used for the calculation of relative viscosity. Since homogeneous Newtonian oils exhibit a viscosity pattern similar to that of human blood, the existence of an "anomalous viscosity" of human blood described by Fahraeus and Lindqvist was not confirmed.
Luteinizing hormone-releasing factor: Partial purification
Authors: Nikitovitch-Winer M. B. , Pribble A. H. , Winer A. D.
Published: December 2017

A method has been devised for the partial purification of luteinizing hormone-releasing factor (LHRF) from extracts of ovine median-eminence tissue. Acid extracts are boiled for 20 min, dialyzed against water for 12 hr, and the dialysate lyophilized. The lyophilized residue is dissolved in a small volume of 5 x 10–3 m ammonium acetate, pH 4.6, and chromatographed on carboxymethylcellulose with an ammonium acetate gradient to 1.0 m, pH 4.6. Several acidic peptides pass through the column rapidly; a peptide with LHRF activity appears in the effluent at about 0.4 m ammonium acetate. The ability of various fractions to induce ovulation on intrapituitary infusion into "atropine-pentobarbital-blocked" proestrous rats was used as the biological test for the release of LH. It was found that, following the infusion of the LHRF-containing fraction, 42 of 54 animals ovulated, while no ovulation was observed in 64 animals treated with any of the other fractions. The LHRF material is probably a small polypeptide which is dialyzable, heat stable, has little absorbancy at either 260 or 280 mµ, and does not give a positive reaction with ninhydrin after paper chromatography in the solvent system used. Evidence is presented that the partially purified LHRF is devoid of LH contamination.
Food and water intakes and Walker tumor growth in rats with hypothalamic lesions
Authors: Baillie Peter , Millar Florence K. , Pratt Arnold W.
Published: December 2017

By the 15th day post transplant of the Walker tumor into Sprague-Dawley rats, food intake showed a depression which continued with subsequent tumor growth. A less severe depression of water intake occurred later, indicating dissociation of food and water intake in the tumor bearer. Electrolytic lesions in the lateral area of the hypothalamus of animals at 15 days post transplant produced true aphagia and adipsia; thus the controlling mechanism of the lateral area is functional in the tumor bearer at 15 days. Tumor bearers with sham operations in the lateral area at 15 days showed an initial depression in food and water intakes. Food intake eventually equaled that of nonoperated tumor bearers, but water intake remained depressed, again indicating dissociation of food and water intakes. The Walker tumor was transplanted into rats previously made hyperphagic by lesions in the ventromedial hypothalamus. Food intake began to decline by 15 days, eventually reaching very low levels; thus depression of food intake in the intact tumor-bearing host is not mediated via the ventromedial hypothalamus.
Cardiovascular and respiratory responses from local heating of medulla oblongata
Authors: Chai C. Y. , Mu J. Y. , Brobeck John R.
Published: December 2017

The lower brain stem was explored for cardiovascular and respiratory responses by means of local diathermy in 36 urethane-anesthetized and 48 unanesthetized, decerebrate cats. In the lateral reticular formation, extending from the level of the rostral end of the inferior olivary nuclei to the most caudal portion of the medulla oblongata, localized heating decreased both rate and tidal volume of respiration, with marked bradycardia, a slight change in systolic blood pressure, and some increase in pulse pressure. Electrical stimulation of the same area usually induced forceful inspiration associated with no cardiovascular response. The thermally induced bradycardia, but not the decrease of respiration, was abolished by vagotomy or by the administration of atropine. The same diathermy applied locally to the rostral hypothalamus in the same cats evoked mainly acceleration of respiration with little cardiovascular reaction. The present experiments suggest that the lateral reticular formation of the medulla is as sensitive to thermal stimulation as is the rostral hypothalamus. The significance of the medullary thermal sensitivity, however, is not clear.
Effect of glucose on uptake of l-lysine-H3 in cells of the seminiferous epithelium
Authors: Davis Joseph R. , Firlit Casimir F.
Published: December 2017

The incorporation of llysine-H3 into protein of cells of the seminiferous epithelium of the rat has been studied radioautographically following incubation of slices of testis with the labeled precursor for 1 hr. In addition, the effect of exogenous glucose on protein labeling of the successive cells of the cycle of the seminiferous epithelium of the rat has been investigated. In the absence of added glucose the most heavily labeled cells of the seminiferous epithelium were the resting primary spermatocytes, with little or no label appearing in the remaining cells of the spermatogenic cycle. The addition of glucose caused a significant increase in protein labeling from tritiated lysine in all the cells of the spermatogenic cycle with the greatest degree of stimulation being noted in the pachytene primary spermatocytes and spermatids. It is suggested that the transition from somatic mitosis to the first meiotic prophase is associated with a marked increase in protein labeling, and that the incorporation of radioactive lysine into protein of the pachytene primary spermatocytes and spermatids is the most sensitive to the addition of exogenous glucose.
Circulatory effects of RES depression in the dog
Authors: Banaszak Edward F. , Kampine John P. , Brault Barbara A. , Smith James J.
Published: December 2017

The response of the anesthetized dog to single and repeated doses of colloidal carbon gel (CCG) is quite similar to that reported in other mammalian species. At doses less than 30 mg/kg the clearance rate is high and limited only by splanchnic blood flow. At dose levels above 30 mg/kg the phagocytic index (K) approaches a constant. The minimal dose of CCG for assessment of phagocytic capacity was adjudged to be 40 mg/kg. Large doses of CCG (160 mg/kg) and colloidal SiO2 (350 mg/kg) induced a phagocytic depression accompanied by a marked granulocytopenia as well as prompt and delayed hypotensive reactions. There was a decline of estimated splanchnic blood flow incident to test doses of CCG but no further reduction after an RES-depressing dose of CCG. Colloidal thorium dioxide (4 and 8 ml/kg) did not depress the phagocytic capacity of the canine RES for CCG. It is suggested that the delayed hypotensive reaction may be related to the lesser tolerance to traumatic shock previously reported in RES-depressed animals.
Effect of vitamin D and dietary calcium on parathyroid activity
Authors: Au William Y. W. , Raisz Lawrence G.
Published: December 2017

The effects of variations in vitamin D and calcium intake on parathyroid weight and amino acid uptake were studied in vivo. D-deficient rats on low or normal calcium intake developed hypocalcemia, parathyroid enlargement, and increased parathyroid uptake of α-aminoisobutyric acid (AIB). D-deficient rats fed a high-calcium diet and D-treated rats fed a normal-calcium diet had normal serum calcium concentrations, smaller parathyroids, and lower parathyroid uptake of AIB. When serum calcium concentration of vitamin D-deficient rats was increased acutely by vitamin D treatment, dietary lactose, or injection of calcium, parathyroid uptake of AIB decreased. Low-calcium medium stimulated and high-calcium medium suppressed AIB uptake of parathyroids from vitamin D-deficient rats in vitro. Parathyroids from vitamin D-deficient rats secreted bone-resorbing material in tissue cultures. The data indicate that both size and functional activity of rat parathyroids are inversely related to serum calcium concentration, and do not depend on the presence or absence of vitamin D.
Effect of catecholamines and the renal nerves on renin secretion in anesthetized dogs
Authors: Vander Arthur J.
Published: December 2017

Intravenous infusion of either epinephrine (5–6 µg/min) or norepinephrine (12–16 µg/min) during maintenance of a constant renal arterial blood pressure by means of suprarenal aortic constriction, or stimulation of the renal nerves produced essentially the same effects on renal function and renal venous plasma renin concentration, the latter being measured indirectly by bioassaying the pressor activity produced by plasma incubation under standardized conditions. Glomerular filtration rate (GFR), renal plasma flow (RPF), and sodium excretion were decreased, and renin concentration was increased. The induction of osmotic diuresis during catecholamine infusion or renal nerve stimulation reversed or prevented the increase in renin secretion but did not alter the changes in GFR or RPF. It is suggested that the increased renin secretion induced by catecholamines and renal nerve stimulation in nondiuretic dogs might be the indirect result of the decrease in filtered sodium produced by these procedures. However, a direct effect of the catecholamines and renal nerves on the renin-secreting cells cannot be ruled out.
A method for exposing the rat renal medulla in vivo: micropuncture of the collecting duct
Authors: Sakai Fuminori , Jamison Rex L. , Berliner Robert W.
Published: December 2017

A new method involving partial nephrectomy is described by which the distal portion of the rat renal medulla is made accessible to an investigation by the micropuncture technique. Urinary flow was greater and osmolality less in the partially nephrectomized left kidney than the unoperated right kidney but the urine remained hypertonic. Micropuncture of the collecting duct revealed a rising osmotic gradient toward the papillary tip. Electrical potential differences across the collecting ducts were measured by microelectrode techniques. The lumen was electrically negative with respect to the interstitial fluid (mean - 11 mv). It is clear that medullary hypertonicity persists in the partially nephrectomized left kidney and the collecting ducts retain their ability to reabsorb water and maintain a transtubular potential difference. In these aspects of tubular activity, the exposed rat renal medulla appears to be similar to that of the hamster, but has the advantage of a greater exposure of its length to investigation by micropuncture.
Insulin secretion in glucosamine-induced hyperglycemia in rats
Authors: Martin Julio M. , Bambers Gunta
Published: December 2017

The hyperglycemia response produced by the injection of glucosamine in rats has been studied by comparing the effects of equal doses of glucosamine and glucose on blood glucose, circulating insulin, and pancreatic insulin content. The effect of glucosamine and glucose on insulin release from the islets has been studied in vitro by incubating slices of pancreas from normal rats and from rats injected with glucosamine. After glucosamine injection, the blood glucose rose and the circulating insulin decreased. In the glucose-injected group the hyperglycemia was lower and the circulating insulin higher. Insulin output from incubated pancreatic slices of normal rats rose when the glucose concentration in the medium was increased or when tolbutamide was added. A decrease below the base line occurred on the addition of glucosamine or when pancreas slices from glucosamine-injected rats were incubated. Insulin injection decreased the hyperglycemic effect of glucosamine whereas tolbutamide was ineffective. These results suggest that glucosamine exerts an inhibitory effect on insulin release from the pancreas.
Effects of infusion of catecholamines and angiotensin II on renin release in anesthetized dogs
Authors: Wathen Ronald L. , Kingsbury W. S. , Stouder D. A. , Schneider E. G. , Rostorfer H. H.
Published: December 2017

Renin release was studied during the infusion of catecholamines (.7–5.6 µg/min) and angiotensin II (.25–1.05 µg/min) into the renal artery, and also during and following iv infusion of 16 µg/min noradrenaline. Filtration rate (Ccr), RPF, and RBF were estimated from the renal clearance of creatinine and the extraction ratio. Marked increases in renal vein renin titer and V-A renin difference occurred within 1 min of the onset of infusion of catecholamine into the renal artery and continued for 15 min beyond the infusion period. This infusion was always accompanied by diminished renal function. During iv infusion of noradrenaline, renin release did not usually occur, but on stopping the iv infusion, the ensuing fall in blood pressure was coincident with a marked release of renin apparently unaccompanied by decreased renal function. Infusion of angiotensin into the renal artery, in spite of causing renal vasoconstriction and marked decrease in urine volume, was not accompanied by renin release. The difficulties of measuring renin release under these conditions are discussed.
Effects of rapid changes in salinity on the renal function of a euryhaline teleost
Authors: Fleming Warren R. , Stanley Jon G.
Published: December 2017

Techniques developed to study renal function of the euryhaline teleost, Fundulus kansae, are described. Effects of a sudden transfer from fresh water to sea water on urine flow and urine and serum osmotic pressures were studied. Glomerular filtration rates (GFR) of animals adapted to fresh water and to sea water for 7 days were estimated. Urine flow was found to be a function of size and of handling, as well as of salinity. Animals held in fresh water showed an initial diuresis which reached a peak approximately 2 hr after cannulation. Urine flow thereafter was in the range of 200 ml/kg per day for fish weighing 1.58 ± 0.3 g, and the estimated GFR was 600 ml/kg per day. Animals held in sea water had urine flows ranging from 5 to 20 ml/kg per day, and filtration rates ranging from 20 to 45 ml/kg per day were estimated. The urine collected from the 2nd to approximately the 10th day after a sudden transfer into sea water was hypertonic to the serum. It is concluded that both a reduction in GFR and an increase in the tubular reabsorption of water are elements of renal function utilized when this animal moves from a hypotonic to a hypertonic environment.