bluuebunny/crossref_metadata_2025 huggingface dataset:
Variations in the prothrombin complex of different species
Authors: Quick Armand J. , Collins Richard , Taketa Fumito , Hussey Clara V.
Published: December 2017

The prothrombin concentration of man, dog, rabbit, cat and cow as determined by the two-stage method is about the same but in sheep is only half as great. The one-stage prothrombin time of the plasma of these species varies greatly and is dependent upon the type of thromboplastin employed, the exposure to foreign surface and various serum factors as well as the concentration of prothrombin. Factor V (labile factor) is present in excess in all so that it is not a determinant. Acetone-dehydrated brain tissue is a satisfactory source of the thromboplastin factor since it can be prepared fairly free of contamination with serum. Variation of activity on various brain preparations cannot be explained satisfactorily on species or group specificity but can in part be accounted for by the synergistic action of an agent in brain tissue with a serum factor or factors which appear to be related to both factor VII (stable factor) and factor IX (PTC). A high yield of thrombin is obtained from human plasma by the thrombin production test but a strikingly low amount from the plasmas of the five other species.
Physiological factors influencing coronary blood volume in isolated dog hearts
Authors: Salisbury Peter F. , Cross Cecil E. , Rieben P. Andre
Published: December 2017

Measurements of the weight and of the residual blood in an isolated, perfused heart permitted investigation of factors which influence coronary blood volume. Coronary blood volume was a near linear function of coronary arterial pressure between 30 and 125 mm Hg and was also linearly related to coronary flow in fresh preparations. For each 1 mm Hg change of mean coronary perfusion pressure, a corresponding change of the coronary blood volume occurred, amounting to about 100 mg blood/100 gm perfused heart. Decreases of contractile strength or heart rate caused reversible increases of the coronary blood volume.
Alpha and gamma fiber responses to peripheral nerve and reticular formation stimulation
Authors: Koizumi Kiyomi , Ushiyama J. , Brooks Chandler McC.
Published: December 2017

Recordings were made from single alpha and gamma fibers of the ventral rootlets of anesthetized cats. Most of the gamma fibers were spontaneously active but alpha fibers were not. Both types of fiber were activated by skin and muscle nerve stimulation. In a few cases monosynaptic gamma fiber reflexes were seen but for the most part latencies indicated polysynaptic gamma reflex circuits. Silent gamma as well as alpha fibers were reflexly activated but a single reticular formation stimulation was not found to excite silent gamma fibers nor to have a facilitatory action other than on alpha motoneurons. Repetitive reticular formation stimulation temporarily augmented repetitive firing of some gamma fibers but eventually produced a long-lasting silent period. Single pulse stimuli of the reticular formation and afferent nerves likewise produced a silent period regardless of whether or not an initial excitatory action had occurred. Silent periods persisted for a longer time than did the excitation responses although those created by reticular formation stimulation did not invariably inhibit reflex excitation of gamma neurons. Gamma fibers appeared to be more readily affected than were alpha units; stronger afferent nerve or reticular formation stimuli were required to excite or inhibit alpha motoneurons. The gamma motoneurons possessed a functional similarity to interneurons.
Urinary excretion of indolic compounds in rats with intestinal pouches
Authors: Donaldson Robert M. , Dolcini Horacio A. , Gray Seymour J.
Published: December 2017

The urinary excretion of indican and of free and total indoleacetic acid is significantly increased in the rat in the presence of a localized area of intestinal stasis produced surgically by the creation of a pouch in the small intestine. Tryptamine, serotonin and 5-hydroxyindoleacetic acid excretion in the urine is not altered. Evidence that intestinal stasis and bacterial activity within the pouch are responsible for the increased amounts of indican and indoleacetic acid in the urine is supported by the facts that a) indole compounds are not increased in the urine when the intestinal pouch is formed so that peristalsis keeps it empty, b) removal of the intestinal pouch results in a reduction of indican and indoleacetic acid to normal levels within 24 hours and c) oral administration of neomycin promptly reduces the excretion of these compounds to normal levels.
A bio-assay and histochemical study of antidiuretic hormone in adrenalectomized rats
Authors: Lauber Jean Kautz
Published: December 2017

This study is an attempt to shed some light on the complex interrelationship between the hypothalamico-neurohypophyseal system and the adrenal cortex in control of mammalian water balance. Bio-assays of plasma antidiuretic hormone levels have been combined with densitometric estimations of the amount of histochemically stainable secretory substance in the neurohypophysis. Determinations were made at various intervals after bilateral adrenalectomy, as well as on unoperated control animals. Both types of determinations revealed considerable variation in antidiuretic hormone during the period of developing adrenal insufficiency. Several new techniques applied to this problem in the present study have yielded, it is felt, more precise information than has been obtainable in similar previous studies utilizing less specific methods.
Changes of visual pattern discrimination in adult cats after removal of an aspecific area of cerebral cortex
Authors: Gualtierotti Torquato
Published: December 2017

In the curarized cat, a well-defined, aspecific trigger area (TA) of the cortex, situated in front of the visual cortex caudally to the crux, originated a widespread, 10/sec afterdischarge following stimulation of the lateral geniculate body of the same side. Removal of the TA significantly impaired the visual pattern discrimination of previously trained adult cats, increasing their time of response. Untrained cats were not susceptible to training when the TA had been destroyed on both sides. Removal of an equivalent visual area did not alter visual pattern discrimination. The stimulation of the lateral geniculate body of the same side did not elicit the 10/sec afterdischarge if the TA had been completely destroyed. It is concluded that the TA might be concerned with higher sensory-motor integrative activity.
Comparative abilities of thyroxine and triiodothyronine as inhibitors of pituitary thyrotropin secretion in cattle
Authors: Premachandra B. N. , Pipes G. W. , Turner C. W.
Published: December 2017

A technique is described using radioactiveiodine (I131) and the goitrogen, Tapazole, in mature dairy cows, to compare the relative biological activity of l-thyroxine (T4) and l-triiodothyronine (T3) in individual animals to inhibit pituitary thyrotropin (TSH) release and, in turn, release of thyroidal-I131. The minimal amount of either hormone required is considered the equivalent T4 or T3 secretion rate. The individuals of the Holstein breed showed a mean molar relation of 1:2.5, which was significantly higher than the means of the other breeds. The mean of 22 animals showed a ratio of 1:2.14, indicating that T3 is slightly over twice as effective as T4 in blocking TSH and thyroidal-I131 release. While T3 is more potent in blocking TSH discharge, it was observed that upon withdrawal of T4 and T3 the resumption of thyroidal-I131 release was more rapid after T3 administration.
Chemoceptor reflexes in swine
Authors: Bredeck H. E. , Herin R. A. , Booth N. H.
Published: December 2017

Respiratory reflexes originating from chemoceptors in the carotid body have not been previously demonstrated in swine. These investigations indicate the carotid sinus areas of pigs possess chemoceptors sensitive to potassium cyanide and lobeline. Stimulation of these chemoceptors causes a reflex stimulation of the respiratory center and hyperpnea. The sensitivity of the chemoceptors to potassium cyanide is apparently enhanced by vagotomy, whereas this procedure does not reduce the threshold to lobeline. Intravenous injections of cyanide reflexly stimulate the respiratory center if one or both carotid sinus areas are intact. Following bilateral vagotomy and denervation of the chemoceptors in the carotid sinus regions, no respiratory response is elicited by intravenous injections of potassium cyanide.
Local ventricular bulging after acute coronary occlusion
Authors: Tatooles Constantine J. , Randall Walter C.
Published: December 2017

In open-chest dogs, anesthetized with Nembutal, under positive pressure respiration, the coronary arteries were dissected out, and an umbilical ligature was placed about the left coronary artery, the anterior descendens, or the circumflex artery. Strain-gauge arches were sutured directly to the myocardium both in and out of the distribution of the occluded coronary artery. Blood pressure and ECG were also recorded before, during, and after arterial occlusion, which lasted for periods varying from 10 sec to 20 min. During occlusion of a large coronary artery the force of contraction of the affected myocardium decreased, and with continued occlusion the ischemic area no longer contracted but bulged during ventricular systole. Lead II of the ECG remained unchanged during ventricular bulging. After several successive occlusions, ventricular bulging became more pronounced and occurred more promptly after occlusion. A slight increase in blood pressure was noticed on the initial occlusion and could be abolished in a fresh preparation by bilateral vagotomy. Also, pulsus alternans was frequently noticed without electrical alternans. Restoration of contraction in the ischemic segment was observed in all instances of occlusion of 1 min or less. Upon release of occlusion, the force of contraction in the ischemic segment was markedly greater than control, with apparently complete recovery during the following 1–3 min.
Testosterone propionate and histamine metabolism in rats
Authors: Kim K. S.
Published: December 2017

Urinary histamine output has been studied under various experimental conditions in rats. Orchidectomy increased the output of free histamine in rats of the Sprague-Dawley strain but not in rats of the Wistar strain. Subcutaneous administration of testosterone propionate (1 mg/rat) suppressed the output of free histamine in ovariectomized rats but not in normal females, which showed the effect only after repeated administration of this hormone. When exogenous histamine (100 µg) was administered at a constant rate over a 4-hr period, only a minute quantity of administered histamine appeared as free histamine in the urine of male rats. In contrast, 23% of administered histamine appeared as free histamine in the urine of female rats. When repeatedly treated with testosterone, female rats eliminated exogenous histamine more like males. The close relationship between testosterone and histamine metabolism in rats is thus clearly demonstrated.
Cold exposure and acclimation in alloxan-diabetic rats
Authors: Poe Robert H. , Davis Thomas R. A.
Published: December 2017

The survival rate of alloxan-diabetic rats at 5 C was significantly less than that of control rats living at the same low environmental temperature. One-half of the diabetic animals died within the first 7 days of exposure while the remainder exhibited a marked susceptibility to cold injury in the form of tail gangrene. Shivering was decreased upon re-exposure to cold in both the diabetic and control rats following 20 and 45 days of cold acclimation. The diabetic animals had a tendency to shiver less than their controls. Diabetic rats also showed a significantly greater decrease in rectal temperature over a 90-min period at 5 C than did controls, in spite of a similar increase in oxygen consumption. This rectal temperature decrease was observed in both the diabetic and control groups before and after 20 days of cold acclimation. The data suggest that a problem of heat conservation exists in the diabetic rat, but tail-skin temperatures, as recorded, did not bear this out.
Insulin, anaerobiosis, and phlorizin in entry of d-galactose into skeletal muscle
Authors: Lotspeich William D. , Wheeler Anne H.
Published: December 2017

In the eviscerate-nephrectomized rat the increase in the galactose space seen after insulin was significantly prevented by phlorizin in concentrations which by themselves were without effect on this function. Similarly, the d-galactose uptake by rat diaphragm was increased by insulin, and this effect was also significantly reduced by phlorizin in concentrations that had no effect on d-galactose uptake in the absence of insulin. The increased uptake of d-galactose by the rat diaphragm incubated in nitrogen was also significantly reduced in the presence of phlorizin.
Hepatic arterial and portal venous pressure-flow relationships in isolated, perfused liver
Authors: Condon Robert E. , Chapman Niles D. , Nyhus Lloyd M. , Harkins Henry N.
Published: December 2017

Blood pressure responses to alteration in blood flow were studied in the completely isolated, excised liver of the calf during perfusion of the hepatic artery or portal vein. The pressure-flow curves in both of the afferent vessels of the liver are curvilinear, with concavity toward the pressure axis. Resistance increases progressively with increases in perfusion rate; resistance increases are proportionately of greater magnitude than the increases in blood flow demonstrating autoregulation in both hepatic arterial and portal venous systems. The autoregulatory nature of pressure-flow responses is not affected by prolonged perfusion or marked acidosis.
Influence of hydration on renal function and medullary sodium during vasopressin infusion
Authors: Perlmutt Joseph H.
Published: December 2017

Mild and severe degrees of hydration were produced in anesthetized dogs by constant infusion of dextrose in water at different rates. When water diuresis ensued, and after adequate control periods, vasopressin was infused for 2 1/2 hr. The magnitudes of urine flow and Na excretion varied directly and osmolal urine-to-plasma ratio varied inversely with the degree of hydration. During mild hydration, glomerular filtration rate and osmolal clearance remained practically unchanged, whereas during severe hydration they increased. In another group of animals, similarly prepared, kidneys were removed at appropriate times and tissue was obtained from various areas for Na analysis. During uninterrupted water diuresis the medullary gradient for Na was practically dissipated. Vasopressin promoted the repletion of medullary Na during mild hydration, but only slightly ameliorated the disturbance during severe hydration. These data demonstrate that during vasopressin infusion the renal concentrating response and Na excretion were significantly modified by the degree of hydration, and evidence is presented for several possible causes.
Characterization of a soluble plasminogen activator from kidney cell cultures
Authors: Painter Robert H. , Charles Arthur F.
Published: December 2017

Primary cultures of monkey kidney cells and cultures of an established line of dog kidney cells have been shown to accumulate a fibrinolytic agent during the growth of the cells in serum-free media. A differential fibrin plate assay has been used to demonstrate this and show that the agent is an activator of plasminogen and not a fibrinolysokinase. The active material has been concentrated and its properties as an activator confirmed by a caseinolytic assay method. The plasminogen activator from both cultures has been shown by high speed centrifugation to be in solution and its properties have been found to be similar to urokinase.
Intrinsic cardiac output variability in the anesthetized normal and splenectomized dog
Authors: Smith Louis L. , Foster Raymond L. , Muller Walter
Published: December 2017

In an effort to determine variations in the normal hemodynamics of the dog, serial cardiac output and blood pressure measurements were made and peripheral resistance values calculated in the same animal over a prolonged period of time. The hemodynamic effect of splenectomy was observed by comparing seven lightly anesthetized normal dogs with seven splenectomized animals. The standard deviation for serial cardiac output values in individual normal dogs was ±6–15%. The mean value for the standard deviation in the entire group was ± 10.5%. The standard deviation for the cardiac output values in splenectomized dogs varied from ±6.5 to 29.5%. The mean value for the standard deviation in this group was ± 15%. Although the normal dogs appeared to have a more stable cardiac output, statistical evaluation of the data showed no significant difference in cardiac output variation between normal and splenectomized dogs. The intrinsic variation in the cardiac output of the dog is apparently physiological in origin and must be considered in interpreting serial observations of cardiac function.
Osmometric behavior of blood cells and of whole body cells
Authors: White H. L. , Rolf Doris
Published: December 2017

When mannitol was added to heparinized dog blood the shrinkage of cell volume agreed with that predicted on the basis of perfect osmometer behavior, i.e., R = 1. After infusion of hypertonic mannitol in saline the ratio of observed to predicted cell hematocrit was somewhat less than that predicted on the basis that whole body cells are perfect osmometers, i.e., R for whole body cells was greater than 1. When allowance is made for the sodium calculated to have moved out of body cells the agreement between observed and predicted cell hematocrit becomes quite close.
Effects of adrenergic and cholinergic blocking agents on hypothalamic mechanisms
Authors: Grossman Sebastian P.
Published: December 2017

Double-walled cannulas, allowing repeated stimulation of the same site in unrestrained animals with crystalline chemicals, were implanted stereotaxically into the hypothalami of 14 albino rats. Histological verification of the intended placements showed that the tips of the cannulas were located in an area between the fornix and the mammillothalamic tract, lateral and dorsal to the ventromedial nuclei. As in previous findings, it was found that the placement of minute amounts of norepinephrine into this area induced vigorous and prolonged eating in food-satiated animals, while the placement of comparable quantities of acetylcholine or carbachol into the identical loci in the same animals induced vigorous drinking in water-satiated rats. Evidence for the neurohumoral nature of these stimulation effects was obtained in experiments demonstrating: a) complete and selective blockade of the adrenergic and cholinergic stimulation effects by central adrenergic or cholinergic blockade, respectively; and b) the effectiveness of precursors of norepinephrine and acetylcholine to mimic the adrenergic and cholinergic stimulation effects. These results suggest that this portion of the hypothalamus contains two populations of neural elements which participate in the regulation of food and water intake and are preferentially sensitive to adrenergic and cholinergic stimulation, respectively. That such neurochemical "coding" may be a functional property of these hypothalamic neurons in the intact animal is suggested by the demonstrated effectiveness of adrenergic and cholinergic blocking agents to selectively reduce normal hunger and thirst, respectively.
Cardioaccelerator and cardioaugmentor points in hypothalamus of the dog
Authors: Fang H. S. , Wang S. C.
Published: December 2017

Comparison of cardioaccelerator and cardioaugmentor responses elicited from the two halves of the hypothalamus of 21 open-chested, vagotomized dogs under chloralose anesthesia showed that stimulation of the right side generally resulted in marked acceleration accompanied by moderate augmentation, whereas stimulation on the left caused pronounced augmentation associated with only moderate acceleration. These differences in degree were statistically significant. This finding suggests that the hypothalamic sympathetic pathways for the cardiac controls, like those of other sympathetic functions, descend predominantly on the ipsilateral sides of the spinal cord.
Electroshock convulsion threshold and organ weights in rats after alcohol consumption
Authors: Zarrow M. X. , Pawlowski A. A. , Denenberg V. H.
Published: December 2017

Rats were given 5% or 10% alcohol as the sole drinking fluid for 129–157 days and the electroshock convulsion threshold obtained. Thresholds for both the minimum seizure and the maximum seizure were determined. In the minimum seizure experiment, values were 21.4 ma for the control group and 25.7 ma for 10% alcohol-treated rats. In the maximum seizure experiment, the average threshold was 34.3 ma for the control group, 48.2 ma for the 10% alcohol-treated group, 39.5 ma for the 5% alcohol-treated group, and 29.8 ma for a formaldehyde-stressed group. In both instances the threshold elevation was statistically significant at the 1% level. No significant effect of body weight was seen on the electroshock convulsion threshold of the normal rat. Postmortem examination failed to reveal significant changes in the liver or endocrine system, and it was concluded that the increased electroshock convulsion threshold after chronic alcohol consumption was probably due to a depressant action of alcohol on the central nervous system.
Metabolism of C14-labeled substrates by rabbit kidney cortex and medulla
Authors: Lee James B. , Vance Vernon K. , Cahill George F.
Published: December 2017

Slices of rabbit kidney cortex and medulla were incubated for 90 min at 38 C in Krebs-Ringer bicarbonate buffer containing C14 labeled substrate. In addition to substrate disappearance and concentrations of glycogen and fatty acids, measurements were made of the amount of radioactive substrate incorporated into CO2, glycogen, and fatty acids per gram of wet tissue. Glucose, fructose, mannose, glycerol, pyruvate, and palmitate were oxidized to a significantly greater extent by cortex than medulla. The concentration of glycogen in kidney medulla was twice that of cortex and was maintained at initial concentrations only in the presence of glucose, which showed a significantly greater incorporation into medullary glycogen than did the other substrates. Under pure anaerobic conditions simulating those in vivo, the present study suggests that the metabolism of medulla is almost exclusively glucose-dependent anaerobic glycolysis. On the other hand, the cortex is capable of utilizing a variety of substrates for a high rate of aerobic metabolism.
An effect of liver extracts on glucose tolerance in rats
Authors: Mertz Walter , Schwarz Klaus
Published: December 2017

The effect of liver extracts on glucose tolerance of intact and eviscerated rats deficient in glucose tolerance factor (GTF) was investigated. Extracts prepared from livers of rats on a wheat-casein ration restored impaired glucose tolerance of GTF-deficient rats to normal with doses of 250–500 µg dry weight per 100 g weight, whereas similar preparations from kidney and spleen were ineffective. Infusion of the liver fraction (.6 mg/hr) increased glucose tolerance of eviscerated rats from about 45 mg to over 70 mg of glucose per 100 g per hour. The results indicate the presence of an active principle which is water soluble, heat stable, and different from GTF. While strongly enhancing the disposal of excess glucose, it does not affect normal blood sugar levels of fasting animals.
Pancreatic secretion in rat: effect of bile stasis and of bile salt
Authors: Kuroyanagi Y. , Necheles H.
Published: December 2017

Obstruction of the common bile duct in the rat (albino, Rockland strain) stimulated pancreatic secretion beginning several hours after obstruction, and lasting as long as 7 days. Bile acid (sodium dehydrocholate) injected intraperitoneally did not change basal pancreatic secretion, but did increase bile secretion. When secretin injection was followed by bile acid, there was a marked increase over the secretin-stimulated secretion. Clinical implications of this mechanism are discussed.
Effect of whole-body x radiation on plasma iron disappearance in the rat
Authors: Blackwell L. H. , Sinclair W. K. , Humphrey R. M.
Published: December 2017

Studies on the plasma disappearance half-time of Fe59 in whole-body and liver- and spleen-shielded rats given 50–800 rad of 200-kvp X rays showed that the half-time became successively longer with doses up to 600 rad (at a level 2.7 times control value). After 600 rad, plasma disappearance half-time began to fall again, but at this level substantial changes also occurred in plasma iron concentration. The time to reach the maximum increase in plasma disappearance half-time continued to rise and was linear with dose up to 700 rad. The changes in plasma iron disappearance half-time have been shown to be directly related to iron uptake changes but the time for the maximum effect in plasma disappearance precedes that for uptake consistently by 0.5 days. Therefore, plasma iron disappearance half-time is a useful practical parameter of radiation injury in the rat up to about the ld50.
Some differences between duodenal and ileal sorption
Authors: Hindle William , Code Charles F.
Published: December 2017

Previous studies have shown that large exchanges of water and sodium occur in both directions across the mucosa of the duodenum between the contents and the blood as if to develop and maintain equilibrium with the plasma. In contrast, in the ileum the exchanges are directed to absorption of the contents rather than equilibration. These findings indicate differences in function of the mucosa of the two sites. To illuminate these, isosmotic and hypertonic solutions of a slowly absorbed substance (mannitol) were placed in duodenal and ileal segments of the small bowels of dogs. The changes in the composition of these solutions and the bidirectional fluxes of sodium and water have been determined. Although mannitol was absorbed by the two sites at equal rates and the osmolality of the contents of both regions changed in a parallel fashion, the composition of the contents in the two sites underwent quite different alterations. In the duodenum the volume was unchanged if the solution was isosmotic and increased if it was initially hypertonic, while in the ileum it decreased in both instances. Sodium always entered the duodenal contents in large quantities, while little appeared in the ileal contents.
Components of the cardiac action potential
Authors: Hoshiko T. , Sperelakis Nick
Published: December 2017

Two components have been observed in the intracellular action potentials of frog ventricular strips under conditions of impaired transmission. The strips were bathed in Ca-free, Mg Ringer's solution and were subjected to passage of current pulses through their length. Under these conditions a "notch" gradually developed at the beginning of the plateau and separated the action potential into a spike and a slow wave. In any given cell, the notch was often more prominent when the conditioned strip was stimulated from one end than from the other. Occasionally a spike in isolation spontaneously alternated with a spike plus slow wave response. The slow waves were generally graded in duration and magnitude with stimulus intensity or duration. The results are discussed in terms of a possible junctional response at the intercalated disc.
Temperature variations in the venous system of dogs
Authors: Afonso Skoda , Herrick J. F. , Youmans W. B. , Rowe G. G. , Crumpton C. W.
Published: December 2017

Respiratory fluctuations in the temperature of blood of the superior and inferior venae cavae and the pulmonary artery of anesthetized dogs are described. Diverse experiments were performed with the objective of elucidating the mechanism of production of these thermal variations. Data obtained were consistent with the hypothesis that changes in the ratio of venous flows draining into the venae cavae related to breathing are the main cause of the observed temperature variations.
Na and K levels in blood and marrow cells of normal and phenylhydrazine-treated rabbits
Authors: Archdeacon James W. , Rohrs Harold C.
Published: December 2017

Sodium and potassium contents of marrow cells, blood cells, and plasma were measured in normal rabbits and rabbits injected subcutaneously with phenylhydrazine to determine if small quantities of this chemical affected the ability of the blood and marrow cells to maintain their normal levels of these ions. There was a decrease in potassium content of red blood cells within 24 hr after administration of the compound, followed subsequently by a slight rise in plasma potassium. Apparently any effect was closely related to the time of blood sampling after the last injection, recovery occurring within several days if injections were not repeated at frequent intervals. The sodium and potassium analyses of normal bone marrow cells revealed differences in ionic concentration dissimilar to normal blood cells, the average sodium concentrations being higher and potassium concentrations lower in the former cells. Separation of marrow cells into three groups by prolonged centrifugation demonstrated a progressive increase in sodium and a decrease in potassium concentration from the lower to the upper stratum, possibly indicating a greater degree of ionic pumping in the more dense cells.
Conditions determining end products of prothrombin activation in serum
Authors: Johnson S. A. , Monto R. W. , McKenna J. L. , Buscaglia M. K.
Published: December 2017

When blood clots normally such a small amount of prothrombin and small quantity of accelerators remain in the hour-old serum that the prothrombin consumption test is prolonged. When blood from a severe coagulation abnormality clots, prothrombin and fibrinogen are both found in serum. When the blood from milder coagulation abnormalities or from transfused severe coagulation abnormalities clots no prothrombin remains in the serum but quantities of the prothrombin-like derivative appear. It is suggested that this component may be a derivative of prothrombin, and a comparison with prothrombin has been undertaken. Studies carried out using disulfide-linkage inhibitors, known to inhibit prothrombin activation, also inhibit the coagulation system supported by this new component. The prothrombin-like derivative is not stable at –25 C for more than a few days whereas prothrombin stored under similar conditions is stable indefinitely.
A humoral reticuloendothelial-depressing substance in shock
Authors: Blattberg Benjamin , Levy Matthew N.
Published: December 2017

The granulopectic activity of the reticuloendothelial system was assessed by measuring the clearance of carbon particles from the blood of splenectomized, normotensive "assay" dogs. When such animals were cross transfused with portal venous blood from splenectomized, normotensive "experimental" animals, there was a small decline (K1 – K2 = 0.0060) in the phagocytic index. However, when experimental dogs were subjected to hemorrhagic hypotension (mean arterial pressure of 40 mm Hg for 90 min), cross transfusion of portal venous blood to the assay animal resulted in a very marked ( P < 0.001) depression in phagocytic activity (K1 – K2 = 0.0218). On the other hand, cross transfusion of femoral artery blood from experimental dogs subjected to hemorrhagic hypotension caused only a slight decline in the phagocytic index of the assay animals (K1 – K2 = 0.0051). The results strongly suggest that a humoral reticuloendothelial-depressing substance is present in the portal venous blood, but not in the femoral arterial blood, of dogs subjected to hemorrhagic hypotension. This substance is probably formed in the gastrointestinal tract in response to hypotension.
Tube flow behavior and shear stress-shear rate characteristics of canine blood
Authors: Charm S. , Kurland G. S.
Published: December 2017

The shear stress-shear rate characteristics of canine blood were determined in a cone and plate viscometer and could be expressed by a power-law equation. The differences in the shear stress-shear rate and tube flow characteristics suggest a marginal gap of plasma at the tube wall. It also appears from these considerations that the gap width of plasma increases with tube diameter. Laminar flow considerations are insufficient for explaining tube flow behavior. High-speed motion pictures indicate collisions between cells in tube flow and the cells do not appear to remain in discrete streamlines. It is suggested that these uncalculated energy losses are the reason why tube flow behavior cannot be predicted from shear stress-shear rate information.
Solution drinking in rats after dehydration and after hemorrhage
Authors: Schnieden H.
Published: December 2017

Dehydrated rats prefer a solution of sodium chloride (78.5 mEq/liter) and an equivalent solution of sodium bicarbonate to water but they have an aversion to a solution containing an equivalent concentration of potassium chloride and to sodium chloride in a concentration of 314 mEq/liter. They also prefer fat-free milk to water. Animals subjected to hemorrhage equivalent to about 45% of their blood volume made no attempt to drink more fluid than control animals during the 3-hr period of observation.
Renal glucose production and uptake in separate sites, and its significance
Authors: McCann William P.
Published: December 2017

Slices of rat kidney cortex, medulla, and papilla were incubated in serum under O2-CO2 mixtures, and their glucose exchanges measured. Cortical slices released more glucose than can be explained by glycogen or other tissue glucose forms, or slice swelling. Medullary and papillary slices, however, rapidly took up glucose, even when NaCl and/or urea were added to the serum to mimic probable in vivo conditions for these tissues. Renal glucose metabolism is discussed on the basis of these and other observations, leading to the following premises: a) glucose is formed in and released from proximal convolutions, while it is less certain that this occurs in distal convolutions; b) loops and collecting ducts, if not other nephron segments, may rely heavily on glucose for metabolic energy; and c) there are circumstantial relations between net renal glucose metabolism and diuresis.
Effect of cations on resistance and responsiveness of renal and forelimb vascular beds
Authors: Frohlich Edward D. , Scott Jerry B. , Haddy Francis J.
Published: December 2017

The local effects of calcium, magnesium, and potassium on renal vascular resistance were determined in the dog by measuring the renal arterial-venous pressure gradient at constant flow during infusion of isosmotic solutions of KCl, NaCl, MgCl2, and CaCl2 into the renal artery. Resistance was increased markedly by CaCl2, decreased slightly by MgCl2, and affected irregularly by KCl. However, KCl regularly decreased resistance in constricted kidneys. MgCl2 decreased the response of the renal vascular bed to locally injected levarterenol and l-epinephrine. Infusion of MgCl2 or KCl into the brachial artery, in an amount almost without effect on forelimb resistance, decreased the response to intrabrachially injected levarterenol. These findings indicate that, except for differences due to the normally dilated state of the kidney, the effects of calcium, magnesium, and potassium on renal vessels are similar to their effects on forelimb and coronary vessels, and that magnesium and probably potassium depress the sensitivity of renal and forelimb vascular muscle to levarterenol.
Catecholamine content of various organs in experimental hypertension
Authors: Wegmann A. , Kako K. , Bing R. J.
Published: December 2017

Nephrogenic hypertension in dogs produced by a unilaterally placed Goldblatt clamp resulted in diminished catecholamine content in the thoracic aorta, both kidneys, and in the spleen. The catecholamine content in heart, brain, and the adrenal glands remained unaffected. Neurogenic hypertension, induced by partial section of buffer nerves, had no significant effect on the catecholamine content of these organs. The influence of the two types of hypertension on sympathetic activity, catecholamine synthesis, and release are discussed.
Action of nicotine on coronary vascular resistance in dogs
Authors: Leaders Floyd E. , Long J. P.
Published: December 2017

The effect of nicotine, norepinephrine, acetylcholine, and sympathetic and parasympathetic nerve stimulation on perfusion pressure in the left descending coronary artery has been evaluated. Nicotine administered intra-arterially produced an increase in coronary vascular resistance as indicated by an increase in coronary perfusion pressure. It was concluded that this results from sympathetic nervous system activity or release of catecholamines from chromaffin tissue. Ganglia or ganglion-like structures are apparently involved. Other drugs and procedures that were used in attempting to localize the site of nicotine action are discussed. The experimental procedures were also used with preparations that measured myocardial force of contraction. The contractile force of the myocardium, as well as coronary perfusion pressure, was increased with intracoronary administration of nicotine or norepinephrine and sympathetic nerve stimulation. Coronary vascular resistance was increased by these agents and procedures. Vagal nerve stimulation or intracoronary administration of acetylcholine usually decreased the force of contraction and coronary perfusion pressure.
Isolation from urine of pyrophosphate, a calcification inhibitor
Authors: Fleisch Herbert , Bisaz Sylvia
Published: December 2017

The minimum value of the product, Ca X P, necessary for calcium phosphate precipitation to occur, was determined in vitro. The addition of 2.2% urine to the solutions raised the mean product from 53 to 105 (mg/100 ml)2, which shows that the urine contains inhibitors to hydroxyapatite precipitation. One of these was isolated and purified. Its characteristics are those of inorganic pyrophosphate. The mean level of urinary pyrophosphate was 2.24 mg P/liter, sufficient to inhibit precipitation of hydroxyapatite. Pyrophosphate is one of the substances permitting urine to be supersaturated with calcium and phosphate; other urinary inhibitors are still to be identified. It is suggested that the phosphate compound present in the plasma which inhibits hydroxyapatite precipitation is pyrophosphate. In bone, pyrophosphatase would act by locally destroying this calcification inhibitor, thus allowing the apatite crystals to form.
Insulin stimulus of leucine incorporation into frog liver protein
Authors: Penhos J. C. , Krahl M. E.
Published: December 2017

Slices prepared from livers of bull frogs ( Rana catesbiana), pancreatectomized and/or hypophysectomized 7 days before, were incubated 2 hr in frog Ringer-bicarbonate solution at 25 C. Incorporation of leucine-1-C14 into protein was subnormal in the pancreatectomized series. The addition of insulin in vitro, with glucose also present in the medium, produced a significant ( P < 0.01) stimulation of amino acid incorporation in the following series: livers from normal fed animals; livers from animals pancreatectomized 7 days before; and livers from animals pancreatectomized and hypophysectomized 7 days before. Neither insulin nor glucose alone gave a significant effect. These results therefore confirm and extend those obtained with rat liver slices showing that insulin can stimulate amino acid incorporation into protein when added directly to liver. The effect is relatively greatest with livers from animals pancreatectomized 7 days before; the insulin effect does not depend on the presence of the pituitary, as it is obtainable with livers from animals hypophysectomized and pancreatectomized 7 days previously.
Electrolyte and amino acid changes in rat brain during maturation
Authors: Vernadakis Antonia , Woodbury Dixon M.
Published: December 2017

Rats 1–45 days old were studied. Plasma Na and Cl concentrations changed little with age, whereas K concentration decreased. Total brain water content and total Na and Cl concentrations decreased progressively, whereas total K concentration increased during maturation. Brain Na and Cl spaces decreased with maturation. Adult brain levels were attained at approximately 21 days. Concentrations of total and protein nitrogen [trichloroacetic acid (TCA)-insoluble] fractions progressively increased with age. The lipid nitrogen fraction (TCA-insoluble and ether-ethanol-soluble) increased progressively, but not markedly, with age, whereas the concentration of TCA-soluble nitrogen did not appear to change during maturation Changes in brain free amino acid concentrations during maturation were as follows: glutamic, γ-aminobutyric, and aspartic acid and glutamine concentrations progressively increased during maturation. In contrast, threonine concentration did not change. Changes in brain Cl space with age were analyzed and found to support the concept that Cl is homogeneously distributed in young rats but becomes progressively more heterogeneously distributed as the animals mature.
Coronary vasomotor tonus in moderate hypothermia
Authors: Cross Cecil E. , Rieben P. Andre , Salisbury Peter F.
Published: December 2017

Coronary blood flow was measured in open-chest preparations with fixed cardiac output and bypassed right heart. Arterial oxygen tension (pO2), pH, and temperature were measured. The slope of regression lines between mean coronary driving pressure (aortic pressure minus left ventricular pressure) and coronary flow indicated directional changes of coronary vasomotor tonus. During periods of blood cooling in nonfailing hearts the coronary vessels dilated only when arterial oxygen tension was permitted to fall, but not when pO2 remained stable. In failing hearts moderate decreases of blood temperature and pO2 did not cause further decrements of coronary vasomotor tonus. It was concluded that blood temperature per se did not influence coronary vasomotor tonus.
Nongenetic prolonged serum cholesterol alteration induced by deoxyribonucleic acids
Authors: Savitsky J. Philip
Published: December 2017

Deoxyribonucleic acid (DNA) was prepared in a purified, undenatured form from a variety of mammalian sources. Preparations of DNA were assayed for their ability to induce a prolonged decrease in serum cholesterol and phospholipid levels in rabbits. Eighteen heterologous DNA preparations from five mammalian species and seven tissues lowered the serum cholesterol following a single injection, with no specificity observed as to species or tissue source of the DNA. Liver DNA was obtained from carefully selected "high-cholesterol" and "low-cholesterol" rabbits and assayed. The DNA from both homologous groups was equally effective in altering the serum lipids. Autologous DNA, prepared from each rabbit's own leukocytes, showed physiologic activity comparable to all other DNA preparations. The data indicate that the altered serum cholesterol regulation induced by heterologous, homologous and autologous DNA is not associated with the transfer of specific, genetic information. It is hypothesized that some DNA molecules in somatic cells may have metabolic regulatory roles associated with their polyelectrolyte physico-chemical properties.
Influence of graded thyroxin levels on mammary gland growth
Authors: Moon Richard C.
Published: December 2017

The effect of graded thyroxin (T-4) doses on mammary growth in hypothyroid-ovariectomized rats treated with 2 µg estradiol benzoate and 6 mg progesterone was determined using deoxyribonucleic acid (DNA) content of the abdominal-inguinal glands as an index of the degree of cellular proliferation. Concomitant injection of estradiol benzoate, progesterone, and 1–2 µg T-4/100 g for 19 days resulted in an increase in mammary DNA. No significant difference in DNA was evident between rats receiving estradiol benzoate, plus progesterone plu 0.5 µg T-4/100 g and those treated with only estradiol benzoate and progesterone. Pituitary lactogen concentration was 28–143% greater in animals receiving T-4 than in those injected with only estradiol and progesterone. In another experiment a single injection of 2.5 or 5.0 µg T-4/100 g into lactating rats lowered the pituitary lactogen content 33–38% when compared with a control value of 1.78 µg/mg pituitary. Pituitary lactogen of rats receiving a single injection of 10 or 20 µg T-4/100 g did not differ from the controls. Thyroxin apparently influences production and secretion of lactogenic hormone, and enhancement of mammary growth resulting from thyroxin administration may be due, in part, to increased secretion of lactogen.
Hemodynamic effects of eledoisin, kallidin II, and bradykinin in unanesthetized dogs
Authors: Olmsted Frederick , Page Irvine H.
Published: December 2017

The hemodynamic effects of bradykinin, kallidin II, and eledoisin were compared in unrestrained dogs. Bradykinin and kallidin II were found to be short-acting depressors that increased cardiac output and decreased peripheral resistance. The effects of eledoisin were similar with 10 to 20 times less dosage. With increasing dosage, cardiac output was greatly reduced rather than raised and reduction of arterial pressure was prolonged. Eledoisin given intravenously lowered the blood pressure elevated by angiotensin. Its depressor effects were potentiated by tetraethylammonium chloride.
Hematological studies in the normal adult Indian camel (Camelus dromedarius)
Authors: Banerjee Sachchidananda , Bhattacharjee Ramesh Chandra , Singh Tej Inder
Published: December 2017

The normal blood picture, different blood indices, and electrophoretic mobility of hemoglobin were determined in the Indian camel with one hump ( Camelus dromidarius). The different values were as follows: erythrocytes, 7.24 million/mm3; hematocrit, 27%; size of red cell, 7.7 µ x 4.2 µ; hemoglobin, 13.1 g/100 ml; mean corpuscular volume, 37.9 µ3; mean corpuscular hemoglobin, 17.4 µµg; mean corpuscular hemoglobin concentration, 47%; red cell sedimentation rate, 1.1 mm/hr; leukocytes, 18,000/mm3; neutrophils, 51%; eosinophils, 6%; basophils, 0.05%; lymphocytes, 40%; and monocytes, 3%. The electrophoretic mobility of camel hemoglobin was less than the mobility of human and monkey hemoglobin and the hemoglobinogram showed only one minor component. In the one-humped Indian camel, the number of red cells was less, the size bigger, and the hematocrit value lower than the values reported for the two-humped camel ( Camelus bactrianus).
Cold effects in rat: plasma and adipose tissue free fatty acids and adipose lipase
Authors: Mallov Samuel
Published: December 2017

Male albino rats were exposed to cold or kept at room temperature for 1–24 hr. Plasmas and epididymal adipose tissues were analyzed for free fatty acid (FFA) concentrations and lipolytic activities of intact sections and homogenates, as well as release of FFA by adipose tissues, determined in vitro. Plasmas of rats exposed to cold had significantly higher FFA levels than did plasmas from controls, and intact epididymal adipose tissue sections from cold-exposed rats had higher FFA concentrations, released greater quantities of FFA, and manifested higher lipase activities in the presence of activated triglyceride substrate than did sections from control rats. Exposure to cold may increase FFA mobilization from adipose tissues as a result of enhanced lipolytic activity, due to lipase activation by catecholamines released from adrenals and sympathetic nerve endings. The enzyme activated did not possess several of the properties characteristic of lipoprotein lipase. Tissue homogenates did not manifest increased activity after cold exposure, possibly as a result of activation by the homogenization process itself.