bluuebunny/crossref_metadata_2025 huggingface dataset:
Postnatal Development of a Left-Right Atrial Pressure Gradient
Authors: van Harreveld A. , Russell F. E.
Published: December 2017

The mean left and right atrial pressures were measured in six groups of 10 kittens each. One group was examined between the 12th and 24th hour after birth, one group after 3 days, after 1 week, 2 weeks, 1 month and 2 months. The left and right atrial pressures were almost equal in the first group. With age an increasing left to right pressure gradient developed. In the oldest group the pressure in the left atrium was almost twice as great as in the right. Parallel with the pressure gradient a difference developed in the wall thicknesses of the left and right ventricles. At birth the ventricular walls were of about equal thickness; at age 2 months the left ventricle wall was more than twice as thick as the right. The relationship between ventricle wall thicknesses and atrial pressures is discussed.
Effect of Certain Fatty Acids on Excretion of Endogenous Cholesterol
Authors: Lin Tsung-Min , Karvinen Esko , Ivy A. C.
Published: December 2017

Twenty-two grams of cholesterol-free diet containing 2 gm of saturated or unsaturated fatty acid was fed to 10 female rats every 2 days. The endogenous cholesterol elimination during oleic and linoleic acid dietary periods were the same as during the fat-free cholesterol-free dietary period. During the palmitic and stearic-acid dietary periods, the endogenous cholesterol elimination increased threefold. The mechanisms involved in cholesterol reabsorption are discussed.
Increased Excretion of Aldosterone in Urine From Dogs With Right-Sided Congestive Heart Failure and From Dogs With Thoracic Inferior Vena Cava Constriction
Authors: Davis James O. , Goodkind M. Jay , Pechet Maurice M. , Ball Wilmot C.
Published: December 2017

Extracts of urine from 11 normal dogs, 9 dogs with cardiac failure and 10 dogs with thoracic inferior vena cava constriction and ascites were assayed for aldosterone-like activity. The activity in urine from dogs with heart failure and from dogs with thoracic caval constriction was equivalent to 52 and 167 µg/day of DCA, respectively, and renal Na excretion was uniformly low. No activity was detected in 4 days' urine from normal dogs but chromatographic fractionation and assay of a 26-day collection of normal dog urine showed Na-retaining and increased K-excreting activity in the aldosterone fraction only. Following bilateral adrenalectomy and discontinuation of DCA therapy in 2 dogs with caval constriction, all urinary aldosterone-like activity disappeared and a natriuresis occurred. Assays of chromatographic fractions of extracts of urine from dogs with heart failure and from dogs with caval constriction revealed activity only in the aldosterone fraction.
Influence of Intravenously Administered Heparin on Clotting of Lymph in the Dog
Authors: von Kaulla K. N. , Pratt E. B.
Published: December 2017

Heparin was given intravenously at rates of 2–3 u/kg/min. or by single injection in doses of 65–290 u/kg to anesthetized lymph fistula dogs. Prolongation of the thrombin and prothrombin time of plasma occurred almost immediately. This effect appeared in the lymph only with the larger doses and after a delay in time. This delay was not abolished by large single doses of heparin. The duration of effect in lymph was shorter than in plasma. These differences from plasma effects were more marked in cervical than in thoracic lymph. The phenomena were attributed to the time element of lymph formation and flow, to delay and screening of large molecules passing from plasma to lymph, and to inactivating and excretory processes.
Electrocardiographic Manifestations of Hypocalcemia Produced With Ethylenediamine Tetraacetic Acid
Authors: Kleinfeld Morris , Gross Milton
Published: December 2017

Electrocardiographic changes associated with the hypocalcemic state induced in rabbits by the rapid intravenous injection of the disodium salt of ethylenediamine tetraacetic acid (EDTA) were studied. The rate of administration was varied between 50 and 120 seconds; more electrocardiographic abnormalities were produced when the EDTA was administered in less than 50 seconds. The most frequent finding was a prolonged Q-T interval caused predominantly by a lengthening of the ST segment. Abnormal T waves were observed in a significant number of animals. Electrical alternans of the T wave, not reported in association with clinical hypocalcemia, was also found. The exact mechanism responsible for the electrical alternans associated with EDTA is unknown.
Effects of Diazonium Salts on Erythrocyte Fragility and Cholinesterase Activity
Authors: Holland W. C. , Klein R. L.
Published: December 2017

Incubation of human erythrocytes in isotonic solutions containing diazonium salts (10–5–10–4m) results in an increased fragility of the treated cells. The degree of hemolysis is most marked when the red cells are suspended in solutions of electrolytes and much less in nonelectrolyte solutions. These findings suggest that the diazo compounds interfere specifically with cation transport processes. It was further observed that these compounds are rather potent inhibitors of cholinesterase, 50% inhibition being reached at a concentration of the order of 10–5 m. Attempts to establish a causal relationship between enzyme inhibition and fragility change were unsuccessful. However, evidence was obtained which suggests that this enzyme system is involved in the process. Data are presented which suggest that the ionized phenolic hydroxyl group of the tyrosine residue may be an essential component of the active sites of the enzyme cholinesterase.
Effect of Ischemia on the Length-Tension Diagram of Mammalian Skeletal Muscle
Authors: Senay L. C. , Schottelius B. A.
Published: December 2017

Ischemia was produced in the gastrocnemii of 13 rats by ligation and section of all soft tissue between knee and thigh. The contralateral muscle in each case served as a control. Isometric length-tension diagrams were obtained for both control and experimental muscles from 4 mm below resting length to 9 mm beyond resting length, stretch being imposed in 1-mm increments. In comparing the experimental and control length-tension diagrams, a 15% loss in active tension at resting length was observed in both the experimental and control muscles when the tension developed during an initial isometric tetanus was compared with tension developed at this length during the course of the length-tension diagram. The cause of this decrease is not certain but fatigue and changes in muscle extensibility were thought to play prominent roles. The active tension developed by the ischemic muscles was found to be less at all degrees of stretch, and in most instances this difference was significant. This tension loss in the ischemic muscles was not constant; plotting the difference between control and ischemic active tension revealed that from –4 mm to +2 mm of stretch the difference increased, while from +2 to +9 mm of stretch the tension loss decreased. This latter finding was further investigated by determining fatigue rates at selected degrees of stretch in ischemic and control muscles of 40 rats. These studies indicated that the ischemic muscles suffered a more rapid loss of active tension developed at degrees of stretch less than +2 mm but the control muscles had a more rapid active tension loss at lengths greater than +2 mm of stretch. An explanation for this is suggested. Development of contracture was thought to be the cause of the increase in the passive tension exhibited by the ischemic muscles.
Changes in the Cardiovascular System Following Total Body X-Irradiation
Authors: Caster W. O. , Armstrong W. D. , Simonson Ernst
Published: December 2017

The cardiovascular system of the rat has been studied by both chemical and physiological methods following total body x-irradiation with: a) a single dose of 700 r (an ld50 dose) and b) chronic doses of 100 r/month or 200 r/month for a 7-month period. Histological changes in the heart were absent. Marked chemical and physiological changes suggest, however, that some type of heart failure may be an important factor in the causation of radiation death. In the first 10 days after 700 r, there were: a) marked decreases in deoxyribonucleic acid and actomyosin concentrations in the heart, b) an edema of the heart and lung, c) an increased peripheral venous pressure, d) electrocardiograph changes (including a progression of changes in rhythmicity), and e) a change in the mechanical action of the heart. These effects were most pronounced at the ld50 death period. Chronic irradiation with 100–200 r/month resulted in similar electrocardiographic changes. The heart and testes were the two tissues whose weights were most sensitive to chronic radiation. Changes in the vascular system following 700 r are described in terms of alterations in tissue Evans blue space. In the heart there is a 30–50% increase in plasma volume from 6–10 days after x-ray.
Δ Protein, a New Fibrous Protein of Skeletal Muscle: Properties
Authors: White John I. , Bensusan Howard B. , Himmelfarb Sylvia , Blankenhorn Brigitte E. , Amberson William R.
Published: December 2017

Solutions of D protein contain a fibrous sub-fraction, Δ protein, whose presence is demonstrated by measurements of sedimentation rate, viscosity and flow birefringence. The presence of such a component is further indicated by fibrous material in electronmicrographs. Dissociation of the Δ protein molecule can be accomplished by lowering the ph. Reassociation occurs when the ph is raised. Possible relationships between Δ protein and tropomyosin are discussed. It seems possible that Δ protein may form the elastic filaments in the center of the sarcomere, recently described by several authors.
Wave Form of Cerebellar Evoked Potentials
Authors: Morin F. , Catalano J. V. , Lamarche G.
Published: December 2017

Factors responsible for the waveform of the cerebellar evoked potentials have been studied in cats and monkeys. Such factors include: stimulus strength in anesthetized and nonanesthetized preparations; type of nerve or central tract subject to stimulation, integrity of spino-cerebellar tracts, repetitive stimulation, mode of recording (monobipolar, with needle electrodes). The cerebellar evoked potential consists mainly of a diphasic wave positive negative (potential y), which may or may not be preceded by a faster low amplitude positive deflection ( x). The early deflection ( x) is more often present when foreleg cutaneous nerves are subjected to stimulation, it can however be found occasionally when other nerves of either fore or hindleg are stimulated. Such early deflection is correlated with the arrival of afferent impulses to the granular layer. When the activation of granular layer is not maximal on the free cortex but presumably occurs in those parts buried in the sulci, the early elevations is not recorded from a surface electrode. In this case, which seems to be very frequent, only the main diphasic deflection ( y) is present. The latter is entirely due to cerebellar cortical circuits and follows the arrival of the afferent impulses. It is therefore an index of activation of cerebellar neurons brought about exclusively by afferent inflow and certainly can be taken as a tool for mapping such inflow.
Cerebral Energy Requirement of Neonatal Rats
Authors: Samson Frederick E. , Dahl Nancy A.
Published: December 2017

The survival times of neonatal rats in nitrogen with and without injected iodoacetic acid and at diverse ages and temperatures are presented. It is shown that the survival time in nitrogen is greatly shortened if iodoacetic acid has been injected. Also, in iodoacetic acid treated rats the survival time is decreased with the daily development of the animal; the survival time is lengthened by a decrease in body temperature; the effect of temperature decreases with the daily development of the animal; the logarithm of the survival time has a linear relationship with the body temperature. It is concluded that these survival times are a measure of the energy requirement of the respiratory centers and the influence of age and temperature upon the requirement. A calculation is made which indicates that a deficiency of one micromole of energy-rich phosphate per gram of tissue in the respiratory centers results in the cessation of respiratory movements.
Factors Influencing Survival of Rats in Fasting
Authors: Rixon R. H. , Stevenson J. A. F.
Published: December 2017

The individual duration of survival of adult rats in complete fasting varied considerably; the range at an environmental temperature of 22°C was 6–16 days, at 2–5°C, 1–7 days, and in thyroidectomized animals at 22°C, 15–25 days. This variation in survival was not closely related to the initial body weight but was related to the individual proportionate body weight loss per day and the total proportionate weight loss sustained before death. The individual proportionate rate of weight loss has been correlated with the metabolic rate indicating that the former reflected the metabolic rate of the animal. The duration of survival in fasting has been correlated with the individual metabolic rate, whether measured before or during fasting. Since fasting did not obliterate or reduce the individual differences in metabolic rate, it was possible to predict the individual duration of survival from knowledge of the prefasting metabolic rate. The total proportionate weight loss, which also influenced the survival time in fasting, was altered by changes in the environmental temperature and probably by other factors. The previous diet whether high in protein, fat or carbohydrate had little effect on the duration of survival. Fasting caused a decrease in the metabolic rate of intact rats at 22°C but no change in that of thyroidectomized rats or of rats living in the cold.
Inhibition of Isolated Auricles by Anticholinesterases and Reactivation With Atropine and Epinephrine
Authors: Katsh Seymour
Published: December 2017

The chronotropic and inotropic responses of spontaneously beating isolated auricles of the guinea pig were studied in vitro during exposure to anticholinesterases. Carcholin and Mecholyl were most effective in arresting or inhibiting the atria, whereas neostigmine, physostigmine and strychnine were less potent. It was possible to overcome the inhibition or arrest in all cases except that of strychnine by means of atropine or epinephrine. After strychninization, atropine failed to induce contractions, whereas epinephrine did restore spontaneous rhythmicity. Reactivation by atropine was characterized by a return of amplitude and rate of contraction to preinhibitory levels. Reactivation by epinephrine was followed by an acceleration of rate and an increase in the amplitude of contraction above preinhibition levels.
Succinic and Cytochrome Oxidase Activity of Rat Liver Mitochondria After in Vitro Irradiation With Ultraviolet Light
Authors: Canzanelli Attilio , Sossen Rhea , Rapport David
Published: December 2017

Five per cent suspensions of rat liver mitochondria were irradiated with ultraviolet light for varying periods of time and the succinoxidase and cytochrome oxidase activity were determined. Both succinoxidase and cytochrome oxidase activity were reduced by irradiation with ultraviolet. The order of magnitude of the ultraviolet energy necessary to produce such changes is much less than that necessary to produce chemical changes in nucleic acid derivatives, and approaches the amount which has been shown to produce lethal and other biological effects.
Central Localization of the Osmotic Control Center
Authors: Zuidema George D. , Clarke Neville P.
Published: December 2017

Intracarotid injections of hypertonic solutions cause marked antidiureses in lightly chloralosed dogs. Intrafemoral injections of identical solutions of hypertonic saline and urea were done with resulting slight diureses, reflex flexing of the leg and increased urine osmolarity. Femoral artery injections of hypertonic sodium sulfate are followed by antidiureses which are explained, at least partially, by active reabsorption of the sulfate ion in the proximal renal tubules. The absence of evidence of antidiuretic activity following intrafemoral artery injections and the marked antidiuretic effect demonstrated following intracarotid injections lends support to the theory of central localization of the osmotic control center.
Function of Pancreatic Juice in Fat Utilization in the Rat
Authors: Karvinen Esko , Lin T. M. , Ivy A. C.
Published: December 2017

Tripalmitin, a saturated, and triolein, an unsaturated fat, and their respective fatty acids were fed at a level of 8% by dry weight of the diet to 12 sham operated control and 12 pancreatic duct ligated rats. It was found that exclusion of pancreatic juice significantly decreased the utilization of both triolein and tripalmitin. Thus, the pancreatic juice is essential for the utilization of both saturated and unsaturated fat. It was found also that exclusion of pancreatic juice did not influence the absorption of oleic and palmitic acid. Therefore, it is concluded that pancreatic alkali does not exert any significant effect on the absorption of fatty acid in the amounts fed whether saturated or unsaturated, and that pancreatic lipase and/or the facilitation by pancreatic alkali of the hydrolysis of fat by any lipase present in the intestine is the factor (or factors) in pancreatic juice which is essential for the complete utilization of both saturated and unsaturated fat. The observed decrease in the utilization of tripalmitin produced by the exclusion of pancreatic juice was not larger than the decrease in the utilization of triolein; therefore, it is concluded that a desaturation of fat by a pancreatic dehydrogenase is not essential for the absorption of saturated fat.
Central Pathway for Cutaneous Impulses in the Cat
Authors: Catalano Joseph V. , Lamarche Guy
Published: December 2017

Spinal pathways involved in the transmission of fast cutaneous impulses from the foreleg to the sensory cortex were studied by oscillographic methods. By means of acute cord incisions it was established that in addition to the dorsal column another ipsilateral pathway is available for such impulses. The course of this pathway coincides with that of the dorsal spinocerebellar tract up to the first two cervical segments. At this level, following a relay in the lateral cervical nucleus, a crossing to the opposite ventral funiculus occurs. The overlapping of this pathway with other ascending systems of similar course is discussed.
Comparative Effects of ACTH and LSD on Urinary Corticosteriods in Guinea Pigs
Authors: Nadel Eli , Burstein Shlomo , Hoagland Hudson
Published: December 2017

Effects of lysergic acid diethylamide (LSD) and of adrenocorticotrophic hormone (ACTH), administered alone and in combination, on the urinary excretion of three corticosteroids, 6ß hydroxycortisol, 2α hydroxycortisol and cortisol, were compared in four series (11 g.p./series) using inbred strain 2 guinea pigs to see whether some of the effects of LSD were mediated by way of pituitary gland stimulation. ACTH (10 mg) significantly increased the urinary excretion values of the three corticosteroids. There was no increase in corticosteroids following administration of LSD (50 mg). LSD given in combination with ACTH at the above doses did not alter the values observed after ACTH alone.
Fructose Phosphorylation and Dephosphorylation by the Intestinal Mucosa of the Rat During Fructose Absorption
Authors: Papadopoulos Nicholas M. , Roe Joseph H.
Published: December 2017

The role of phosphorylation in the absorption of fructose from the intestinal tract of the fasted rat by in vitro and in vivo techniques was studied. The authors' method for the determination of fructose phosphate esters was used and these esters were identified by paper chromatography and copper reduction techniques. Buffered homogenate of intestinal mucosa of a fasted rat, mixed with ATP, MgCl2, KF and fructose, when incubated at 30°, showed the formation of fructose-6-phosphate and fructose-1, 6-diphosphate at a rate that corresponded to the decrease in free fructose. The same homogenate, mixed with fructose-1, 6-diphosphate and incubated at 37°, showed the formation of fructose-6-phosphate and free fructose at a rate that corresponded to the decrease in the concentration of the diphosphate ester. Following intraduodenal injection of fructose solution into anesthetized fasted rats, homogenates of the intestinal mucosa showed the presence of fructose-6-phosphate and fructose-1, 6-diphosphate in average concentrations 14 and 5 times, respectively, those found in control muocsa, also concentrations of free fructose in the blood of the portal vein up to 24.6 mg % were observed. The large increase in fructose phosphate esters in the intestinal mucosa, observed after fructose administration, suggests that phosphorylation of sugars in absorption serves a more extensive function than to initiate glycolysis for the normal metabolism of the mucosal cells. The data obtained suggest that phosphorylation and dephosphorylation are functional steps in the absorption of fructose from the alimentary tract of the rat.
Analysis of Effects of Hypothermia on Central Nervous System Responses
Authors: Suda Isamu , Koizumi Kiyomi , Brooks Chandler McC.
Published: December 2017

Progressive uniform cooling of the spinal cord and brain was found to produce a phase of hyperresponsiveness between temperatures of 35°C to 25°C. Below this level all recorded reactions were reduced in magnitude. During this phase of hyperresponsiveness the cerebral and cerebellar evoked potentials were increased in amplitude and duration; component waves of the electroencephalogram and electrocorticogram were not increased in frequency but increased in amplitude; all reflexly produced responses were greatly augmented in amplitude and duration; stimuli applied elicited responses from a greater number of elements. Conditioning stimuli which produced no propagated response became effective during the hyperresponsive phase of hypothermia; the following testing stimuli also elicited a greater reflex discharge. The duration but not the amplitude of the action potentials recorded intracellularly from the individual afferent fibers in the dorsal columns, dorsal roots, interneurons and motoneurons were increased during hypothermia. All elements of these potentials were prolonged by cooling the cord. The depressant action which developed as hypothermia progressed eventually abolished the soma-dendritic components of the antidromic and orthodromic single cell potentials but the NM and postsynaptic potentials persisted until lower temperature levels were attained. Fiber action potentials showed a similar diminution at very low temperatures. The longer duration of the signal (the afferent potential), the greater desynchronization of multiple elements involved in transmitting the excitatory process and a possible decrease in accommodation were considered to account for the augmentation in response during the early stages of progressive hypothermia. In hypothermia impulses entering the cord over muscle afferents which normally evoked only a monosynaptic reflex produced a polysynaptic response and a discharge out the spinal sympathetic pathways. There was a loss of specificity of reflex pathways.
Responses of the Inferior Olive to Peripheral Stimuli and the Spinal Pathways Involved
Authors: Morin F. , Lamarche G. , Ostrowski A. Z.
Published: December 2017

Electrical stimulation of mixed and cutaneous nerves of the hindleg of cats activated the medial and ventral accessory olives of the opposite side; small responses were also present in the same parts of the ipsilateral olivary complex. No responses were present following stimulation of nerves to muscle (hamstrings, nerves to gastrocnemius) or of cutaneous nerves of the foreleg. The main and constant component of the olivary potentials is a negative wave the duration and amplitude of which depends on the strength of the peripheral volley and particularly on the activation of the gamma-delta groups. It is likely that spino-olivary projections play some role in the general reaction to painful stimulation. By means of acute cord incisions it was established that spino-olivary fibers are mainly crossed with respect to the stimulated side and run in the ventral funiculus of the cord.
Metabolic Response of Dogs to Hypoxia in the Absence of Circulating Epinephrine and Norepinephrine
Authors: Greene Nicholas M. , Phillips Ann D'E.
Published: December 2017

The importance of epinephrine and norepinephrine in the etiology of the metabolic effects of hypoxia is emphasized by the observation that dogs incapable of releasing these substances showed significantly less change in blood lactate and potassium during forced ventilation with 2.7% oxygen than did control dogs.
Some Biokinetic Aspects of Calcium Metabolism in Dairy Cows
Authors: Luick Jack R. , Boda James M. , Kleiber Max
Published: December 2017

A study was made to determine how cows which have been prefed low Ca:high P diets are better able to maintain normal serum Ca levels than are cows prefed high Ca:low P diets. Radioactive calcium (Ca45) was employed as a tracer. A procedure is presented by which the reservoirs of mobilizable skeletal Ca may be estimated. It appears that these reservoirs of skeletal Ca are larger and are turning over more slowly in cows which were prefed low Ca:high P diets. Since we found earlier that the low Ca: high P cows were in negative calcium balance, the larger stores of mobilizable Ca must accrue at the expense of stable bone Ca. A comparison of bone Ca specific activity to serum Ca specific activity indicates that nearly all the trabecular bone Ca and from 7 to 17% of the cortical bone Ca (depending upon dietary Ca/P) may be included in the ‘mobilizable Ca pool.’
Postseparation Recovery From Parabiosis Intoxication in the Rat
Authors: Hall C. E. , Hall O.
Published: December 2017

When rats suffering from parabiotic intoxication are separated, the hematologic aberrations which characterize the partners are reversed to normal values. Recovery from the anemic state begins immediately, occurs in an orderly fashion, and is complete within 2 weeks. Recovery from erythremia also averages 2 weeks, although the pattern of recovery is less uniform. It is thought that this reflects differences in the degree of polycythemia, and differences in the rate at which stored erythrocytes are discharged into the circulation. The findings are compatible with the view that the fundamental disturbance in parabiosis intoxication is the acquisition of circulating blood by one of the partners at the expense of the other.
Vascular Responses to Local Cold Injury
Authors: Sullivan Bernard J. , Towle Leo B.
Published: December 2017

The extent of vascular responses to local cold injury is proportional to the length of time the tissue is exposed to the cold source. Following a standard exposure period of 30 seconds all blood flow ceases in the frozen area. Marked arteriolar constrictions occur in the borderline tissue but never in the exposed area. In the postthaw period there is a gradual increase in the rate of blood flow, accompanied by the emergence of many emboli from the injured area. These emboli, apparently of platelet origin, occasionally form thrombi which occlude vessels in the borderline tissue. Within 5 minutes the rate of flow again begins to decline, leading eventually to complete stasis. Stasis begins in the venules and spreads throughout the vascular bed. As stasis develops the packed blood cells produce wide dilations in all vessels in the injured area. Hemoconcentration is the apparent cause of stasis following local cold injury.
Defect in the Renal Tubular Reabsorption of Water Associated With Potassium Depletion in Rats
Authors: Hollander Walter , Winters Robert W. , Williams T. Franklin , Bradley John , Oliver Jean , Welt Louis G.
Published: December 2017

The effect of graded degrees of K depletion on the ability to produce a concentrated urine was studied in Sprague-Dawley rats. With increasing degrees of K depletion, as measured by the concentration of K in fat-free skeletal muscle, there was a progrossive decrease in the maximum urinary concentration. This defect of the renal concentrating mechanism appeared to be better correlated with the degree than with the duration of potassium depletion and could be demonstrated either by the use of exogenous vasopressin or by water deprivation. The potassium-deficient rats in at least one experiment developed a significant polydipsia. The data do not allow any conclusions with respect to the relationship of the polydipsia to the renal concentrating defect except that the latter at least was not severe at the onset of the increased water intake.
Influence of Dietary Protein and Cortisone Acetate on Adrenalectomized Rats
Authors: Wolf R. C.
Published: December 2017

Adrenalectomized immature rats were maintained for 20 days with 0.15 mg cortisone acetate when fed a 20% casein diet. The effectiveness of the maintainence dosage of cortisone acetate (0.15 mg) was only slightly reduced when animals were fed a 5% casein diet, but was ineffective when a protein-free diet was fed. Liver protein concentrations in normal and adrenalectomized rats were comparable. However, cortisone-maintained adrenalectomized rats had less liver glycogen and lipid than their respective dietary controls. Liver protein concentration varied directly with the percentage dietary protein while lipid and glycogen concentrations exhibited an inverse variation.
Rate of Metabolism of Ethanol in the Mouse
Authors: Nelson G. H. , Kinard F. W. , Hay M. G.
Published: December 2017

Female mice were injected intraperitoneally with ethanol, in dosages of 4 gm/kg. The animals were killed exactly 1 or 3 hours later. Control mice were killed first and then injected as described above. The difference between the mean concentration of alcohol in the homogenized tissues of the control group and that in the individual experimental mouse permitted calculation of the rate of alcohol metabolism over a period of 1 or 3 hours. The rate of alcohol metabolism, in grams per kilogram per hour, was essentially the same during either 1 or 3 hours of metabolism. Therefore, it appears that the mouse metabolizes ethanol in a linear manner during the first 3 hours after ethanol is administered.
Effects of Spinal Anesthesia and Adrenalectomy on Blood Pressure Responses to Histamine
Authors: Hilton James G.
Published: December 2017

Experiments were made in dogs to determine the effects of graded doses of histamine on the blood pressure of the adrenalectomized and nonadrenalectomized animal before and after total spinal anesthesia. Before spinal anesthesia adrenalectomy had no significant effect other than the changes due to the lowering of the control blood pressure. After total spinal anesthesia adrenalectomy had no significant effect on the blood pressure responses to histamine. The effects seen as the result of the total spinal anesthesia were a decrease in the amount of fall in blood pressure, a prolongation of the duration of the fall in blood pressure and a lowering of the minimum to which the blood pressure will fall as the result of the histamine action. In dogs under total spinal anesthesia there is no indication of a rise in blood pressure due to a direct release of pressor amines from the adrenal medulla due to the histamine action.
Age Changes in the Urinary Histamine Excretion of Rats
Authors: Keller R. , Burkard W. , Grandjean E. , Abt K.
Published: December 2017

In 577 determinations on 135 rats the age change in urinary excretion of histamine was investigated. After administering water, histamine concentration in 12-hour urine was estimated on the isolated atropinized guinea pig ileum. The results show that histamine concentration in the urine during growth (up to 44 wk.) and the amount of histamine excreted daily per gram body weight decreases with increasing age. Against this, the daily total histamine content of urine does not substantially change during the same period. At older ages (50–120 wk.) both the histamine concentration in urine and the total daily excretion drop substantially, the decrease in 2-year-old rats being almost to 1% of the values in young rats.
Erythrocyte Survival and Blood Volume in the Rat as Determined by Labeling the Red Cells With Cr51
Authors: Hall C. E. , Nash J. B. , Hall O.
Published: December 2017

Blood was withdrawn from male and from female rats, labeled with Cr51 and introduced intravenously into male and female recipients. Blood volume as determined from dilution of the isotopically labeled cells was found to be 7.47 ± 0.15 of the body weight. The half-life of the labeled cells averaged 8 days, and seemed to be unaffected by growth of the animals.
Effect of Severe Hypoxia on Blood-Cerebrospinal Fluid Barrier
Authors: Slobody Lawrence B. , Yang Dorothy C. , Lending Miriam , Borrelli Frank J. , Tyree Marjorie
Published: December 2017

The effect of severe hypoxia on the blood-cerebrospinal fluid barrier of dogs was evaluated from the rate of passage of radioiodinated human serum albumin from plasma to cisternal fluid. Hypoxia was induced by intratracheal administration of varying mixtures of O2 and N2 or by use of a Smith-Jones pressure chamber. Radioiodinated albumin was injected intravenously and cisternal fluid and plasma samples were obtained at various intervals thereafter in experimental and control animals. Hypoxia maintained for 1 hour or longer resulted in a marked increase in the concentration ratio (cisternal fluid radioactivity)/(plasma radioactivity). The concentration ratio was frequently higher after 4 hours of hypoxia than after 24–48 hours in control animals. The slope of CSF albumin-I131 concentration as a function of time for the hypoxic animals was about five times that for the control animals. It is concluded that changes in rate of passage of albumin from plasma into cisternal fluid reflect alterations in the permeability of the blood-cerebrospinal fluid barrier to albumin.
Muscle and Liver Glycogen Levels in Lean and Obese Strains of Mice
Authors: Lyon John B.
Published: December 2017

Muscle and liver glycogen concentrations were determined in six strains of inbred mice (A/Fn, C3H/Fn, C57BL/Fn, I/Fn, BUB and Lt) of which only one could be considered to be truly non-obese. This lean strain, the I, showed higher muscle glycogen in both the fed (on either a 5 or 50% fat diet) and fasted states. In contrast to the other strains their muscle glycogen did not readily deplete following a fast. Two of the strains, the Lt and C57, were considered to be moderately obese and under some conditions they showed somewhat higher muscle glycogen levels than the severely obese strains, the A, C3H and BUB, but this pattern was not consistent. Our data suggest that an inverse correlation exists between muscle glycogen and body fat levels in these six mouse strains. Fed liver glycogen concentrations were usually greater in the five obese strains than in the I strain but no consistent pattern was found in the obese strains. These carbohydrate variations suggested endocrine differences among the strains. However, an explanation of these variations in terms of higher or lower titers of any hormone leads only to contradiction when the fat and protein differences of these strains are also considered.
Plasma Ultrafiltrable Calcium in Respiratory Alkalosis and Acidosis
Authors: Prasad Ananda S. , Brown E. B. , Flink E. B.
Published: December 2017

Dogs were subjected to either 30 minutes of respiratory alkalosis produced by overventilating with a positive pressure pump, or to 30 minutes of respiratory acidosis produced by inhalation of 30% CO2 in O2. Total plasma calcium concentration and ultrafiltrable calcium concentrations were determined on arterial blood samples drawn before, during and following the experimental procedure. In agreement with theory, ultrafiltrable calcium concentration decreased slightly during hyperventilation and increased during respiratory acidosis. A rebound increase in the level of ultrafiltrable calcium in the recovery phase following hyperventilation and a similar but inverse rebound following respiratory acidosis was observed in every case. It is postulated that these changes may be due to concomitant changes in plasma phosphate concentration. Total proteins and fractionated proteins did not show consistent changes in these experiments which could account for the changes observed in the ultrafiltrable calcium concentration. The significant changes in ultrafiltrable calcium concentration observed in these experiments would not be apparent if only total calcium concentration were determined since total plasma calcium concentration changed very little or not at all.
Plasma Ultrafiltrable Calcium Concentration in Posthypercapnic Ventricular Fibrillation
Authors: Brown E. B. , Prasad Ananda S.
Published: December 2017

During four hours of severe respiratory acidosis produced by inhalation of 30% and 40% CO2 in dogs, plasma potassium and inorganic phosphate rose, ultrafiltrable calcium first increased then fell below control level, and total calcium increased slightly. Within 5 minutes after returning the animal to air breathing, potassium showed a further sharp increase, ultrafiltrable calcium a further sharp decrease and total calcium and inorganic phosphate showed no change. With the rise in potassium and fall in ultrafiltrable calcium the UF Ca/K ratio fell to less than one third control value. This appears to be an important factor in the mechanism producing cardiac arrhythmias and ventricular fibrillation in the immediate post-hypercapnic period. In vitro experiments on dog blood indicate that ultrafiltrable calcium varies directly with H+ concentration as expected, and that an increase in inorganic phosphate produces a decrease in ultrafiltrable calcium. Operation of these two factors helps to explain the change in plasma ultrafiltrable calcium observed in the in vivo experiments. It is suggested that the decrease in ultrafiltrable calcium in the presence of the very high phosphate concentrations observed, may be due to the formation of some nonfiltrable calcium phosphate compound. It is possible that the increased phosphate concentration increases the binding of calcium in some other form.
Experimental Motion Sickness in Dogs: Role of Abdominal Visceral Afferents
Authors: Wang S. C. , Chinn H. I. , Renzi A. A.
Published: December 2017

Motion sickness was experimentally induced in dogs by means of a standardized swinging procedure. Subsequently, 21 susceptible dogs were chosen in this series for abdominal sympathectomy and/or abdominal vagotomy. Over a period of about 6 months, these operated animals were retested several times, and it was found that the majority of them (67%) showed increased resistance to swing sickness to a greater or lesser degree. However, because of the relatively high percentage of the remaining dogs which showed no alteration of their swing sensitivity, it is concluded that the visceral afferents from the gastrointestinal tract play no paramount role in experimental motion sickness.
Electrolyte Metabolism in Pyridoxine, Riboflavin and Pantothenic Acid-Deficient Rats
Authors: Diamant E. J. , Guggenheim K.
Published: December 2017

Muscle and plasma electrolyte concentrations were determined in rats suffering from pyridoxine, riboflavin and pantothenic acid deficiencies. Muscle of deficient rats contained more sodium and chloride than that of normal animals. There was also an increase in the plasma chloride content in pyridoxine and riboflavin-deficient rats. A decrease was observed in the potassium content of muscle in pyridoxine, and of the sodium level in plasma of riboflavin deficient animals. Cortisone, when administered to pyridoxine-deficient animals, reduced muscle sodium and chloride, and increased its potassium concentration. No such effect is found when cortisone is injected into normal or adrenalectomized rats maintained on a full diet. A saline load was imposed on pyridoxine-deficient rats. They responded with a diminished excretion of water, sodium and chloride. Cortisone, which under our experimental conditions had no effect upon the excretion of these substances in normal rats, increased however, excretion of water, sodium and chloride, when given to pyridoxine deficient rats. The retention of sodium and chloride in our deficient rats and their increased excretion following treatment with cortisone is interpreted as a consequence of either the decreased glomerular filtration found in pyridoxine, riboflavin and pantothenic acid deficiencies, and/or of the increased tubular reabsorption resulting from adrenal insufficiency, which both can be restored to normal again by administration of cortisone.
Fractionated Dose Effects on Survival and Organ Weights in X-Irradiated Mice
Authors: Kereiakes J. G. , Parr W. H. , Krebs A. T.
Published: December 2017

Intervals between each of five 140-r doses of 1, 3, 5, 7 and 9 hours resulted in survivals of 15, 35, 55, 45 and 40%, respectively, for fractionated total body x-irradiation of mice. A 700-r single dose was 100% lethal. The pattern of the intestinal dry weight response was similar to that for survival. Fractionating the total dose did not seem to significantly alter the 700-r single dose spleen wet weight value. The findings suggest that the fast recovery of the mitotic process and of the nucleic acid metabolism in the small intestine at about 5 hours after irradiation with doses between 100 r and 200 r may be responsible for the observed results for the 5-hour interval fractionated total body x-irradiated mice.
Aldosterone Secretion in Experimental Congestive Heart Failure
Authors: Driscol Thomas E. , Maultsby Maxie M. , Farrell Gordon L. , Berne Robert M.
Published: December 2017

Adrenal vein blood levels of aldosterone were measured in six dogs with experimental congestive heart failure and compared with secretion rates in 19 normal and 2 sham-operated animals. No significant differences in adrenal aldosterone secretion were found. Aldosterone was not detected by chromatography or bioassay in pooled 3-day urine samples from three dogs before or after heart failure was present. The results suggest that in dogs with congestive heart failure (1) increased secretion of aldosterone is not necessary for the initial salt and water retention, and (2) heart failure can exist in the presence of normal secretory rates of aldosterone as determined by analysis of adrenal vein blood.
Effects of Asphyxia and Repetitive Stimulation on Intramedullary Afferent Fibers
Authors: Edisen Adele E. U.
Published: December 2017

Effects of asphyxia and of repetitive stimulation on intramedullary projections of the afferent fibers were studied in spinal cords of cats anesthetized with Nembutal. The spinal cord focal potential, elicited by dorsal root stimulation and recorded from the cord, and the antidromically conducted response of afferent fibers produced by intraspinal needle electrode stimulation and recorded from the dorsal roots, were used as indices of afferent fiber activity. The focal potential and the antidromic response from terminal presynaptic fibers disappeared with 5–6 minutes of asphyxiation. Antidromic responses from preterminal regions were less susceptible to asphyxial block. Asphyxia impaired the ability of both types of responses to follow high frequencies of stimulation. The focal potential and the antidromic responses were observed to follow similar orders of high frequency stimulation. Double pulse stimulation of intramedullary fibers demonstrated a longer refractory period of terminal regions with progressive decrease of refractoriness in more dorsally located regions. A gradient of sensitivity to asphyxia and a postresponse recovery gradient exist along the intramedullary fibers.
Tissue Buffering in Rat Diaphragm
Authors: Rogers Terence A.
Published: December 2017

Excised rat diaphragm muscles were incubated in nutrient media at various hydrogen ion concentrations. Those in the more acid media lost more potassium and more sodium than their controls at ph 7.4, and the extent of the loss was increased by further depression of the ph. The potassium loss was unaccompanied by either chloride or phosphate, nor was there any difference in the weight change or inulin space between the control and experimental muscles. These results are consistent with the theory that intracellular cation exchanges for excess extracellular hydrogen ion.
Evaluation of the Cell Separation Hypothesis of Autoregulation of Renal Blood Flow and Filtration Rate
Authors: Kessler R. H. , Heidenreich O. P. A. , Pitts R. F.
Published: December 2017

Glucose titrations were performed in dogs at normal and low hematocrits. The relationship between glucose load and tubular reabsorption was analyzed for splay. The splay was no greater with low than with normal hematocrit, demonstrating that nephrons saturate at the same plasma level of glucose, despite variations in red cell concentration. This is interpreted to mean that the glucose filtering capacities of glomeruli are matched to the reabsorptive capacities of their attached tubules with both normal and low hematocrits. Pappenheimer and Kinter have suggested that plasma skimming within the interlobular arteries plays an important role in autoregulation of glomerular filtration rate and renal plasma flow. Our data are inconsistent with any significant degree of preglomerular plasma skimming in dogs with normal hematocrit.
Renal Action of Parathyroid Extract in the Chicken
Authors: Levinsky Norman G. , Davidson Douglas G.
Published: December 2017

The renal action of parathyroid extract has been studied in the chicken, in which a renal portal system facilitates separation of renal tubular from systemic and glomerular effects. It was found that net secretion of phosphate occurs in the chicken kidney both at endogenous plasma phosphate levels and during the infusion of phosphate. The rate of secretion seems to be independent of the plasma phosphate concentration. Infusion of parathyroid extract into one renal portal system results in a unilateral increase in phosphate excretion. In some experiments unilateral net secretion of phosphate occurred. No consistent changes in glomerular filtration rate or plasma phosphate concentration occur when parathyroid extract is administered. These results indicate that parathyroid extract has a direct action on the renal tubule in the chicken.
Hypercholesteremic Roles of Plasma Cholate and Phospholipid in Biliary Obstruction
Authors: Friedman Meyer , Byers Sanford O.
Published: December 2017

The probable cause of hypercholesteremia after biliary obstruction, in mature rats, appears to be the hyperphospholipidemia which is effected both by a preceding rise of plasma cholate and the biliary obstruction itself. Thus after biliary obstruction, the rise of plasma cholate occurred far sooner than that of phospholipid and the latter in turn rose sooner than did cholesterol. Following bile duct-inferior vena cava anastomosis, hyperphospholipidemia still occurred although somewhat less intense than that after biliary obstruction. The cholesterol rise after the anastomosis also was less than that after biliary obstruction. The cholate rise was the same in both types of biliary retention. These latter observations suggest not only that the hyperphospholipidemia is caused chiefly by cholate accumulation but also that the cholesterol rise is occasioned by the phospholipid rise. After biliary obstruction, the rise of plasma cholesterol, but not that of phospholipid or cholate, can be accentuated by prior feeding of cholesterol and olive oil. This suggests that some of the excess cholesterol in plasma may be derived from exogenous sources.