bluuebunny/crossref_metadata_2025 huggingface dataset:
Mechanical Impedance of the Dog's Hind Leg to Pulsatile Blood Flow
Authors: Randall James E. , Stacy Ralph W.
Published: December 2017

Femoral arterial pressure and flow were recorded with apparatus capable of following cyclic changes at frequencies greater than those encountered. The records were subjected to Fourier analysis, and impedance magnitude and phase angle relations were computed at various frequencies. The impedance curve showed a dip at 180 cpm and a subsequent rise at higher frequencies, suggesting a resonant system. This suggestion was corroborated by the phase angle curve, which crossed from elastance controlled to inertia controlled behavior at 180 cpm. A simple physical model is suggested which contains some of the frequency characteristics of the vascular system studied. From this model rough values of compliance and inertance were computed.
Effect of Renal Hypertension on the Preference Threshold of Rats for Sodium Chloride
Authors: Fregly Melvin J.
Published: December 2017

To determine preference thresholds of normal and hypertensive rats for NaCl solutions a cafeteria or choice experiment was performed in which two bottles of fluid were available to each rat. One bottle (reference) always contained distilled water while the second bottle (test) contained a NaCl solution. The concentration of test solution was changed every 4th day, at least 14 different concentrations being used. Preference thresholds of normal and hypertensive rats were the same and lay between .008 and .016 m. Normotensive rats preferred NaCl solution to water at all concentrations above threshold while hypertensive rats showed the same preference only at concentrations ranging from .016–.090 m. A relative NaCl aversion appeared in the hypertensive rats when the concentration of test solution offered was .090 m or greater. Hence, the NaCl aversion of hypertensive rats cannot be attributed to a difference in acuity in differentiating between NaCl solutions and water. Furthermore, the aversion depends in part on the concentration of NaCl solution given, the aversion threshold being about five times higher than the preference threshold.
Increased Permeability of the Frog Bladder to Water in Response to Dehydration and Neurohypophysial Extracts
Authors: Sawyer Wilbur H. , Schisgall Richard M.
Published: December 2017

Dehydration, neurohypophysial extracts and synthetic oxytocin all increase the rate of reabsorption of urine from the bladder of the frog. Increased permeability of the frog bladder to water, facilitating the osmotic flow of water, appears to be the basis for this response. Increased permeability of the skin and the renal tubule occurs under similar circumstances. The hypothesis is advanced that a common mechanism is involved, possibly the dilatation of pores, in response to neurohypophysial hormones in amphibian skin, bladder and nephron and in the mammalian nephron.
Sulfate Content of Rat Kidney Cortex in Vitro
Authors: Berglund Fredrik , Deyrup Ingrith
Published: December 2017

Slices of rat renal cortex incubated in vitro show, under defined conditions, accumulation of sulfate, demonstrable by benzidine precipitation and by isotope (S35O4) techniques. The two methods agree in the case of slices incubated in KCl-sucrose. After incubation in NaCl-sucrose, however, S35 is distributed in only half of the benzidine-precipitable sulfate.
Sympatho-Adrenal Stimulation by Carbon Dioxide and the Inhibitory Effect of Carbonic Acid on Epinephrine Response
Authors: Tenney S. M.
Published: December 2017

Carbon dioxide serves as a potent stimulus to increase the titer of circulating sympatho-adrenal catechol amines in the cat. Using the denervated nictitating membrane as an assay method the CO2 threshold for adrenal stimulus was determined to be about 15% concentration in alvcolar air. Adrenalectomy decreased by 60% the catechol amine titer initiated by 30% CO2, but hepatectomy was ineffective. The stimulant effect of CO2 in this action was specific and was not dependent on the change in hydrogen ion concentration. The spinal cat was almost as responsive as the normal to CO2 stimulus, but if the cord was destroyed only a very low catechol amine concentration could be detected with comparable stimulus. In the intact cat much of the inhibition of response to administered epinephrine by CO2 is more apparent than real, because the CO2 itself serves as a stimulus to raise the endogeneous epinephrine titer and each subsequently administered test dose of epinephrine was then examined against a background of hormone action. Because of the alinear shape of the epinephrine dose-response curve this can be misinterpreted as ‘inhibition.’ There was however, a direct CO2 inhibition of epinephrine-induced smooth muscle contraction which was most apparent in the range 3–15% alveolar CO2. Sympathetically innervated and denervated structures were inhibited to the same degree.
Fat Metabolism in Experimental Obesities
Authors: Zomzely Claire , Mayer J.
Published: December 2017

In vivo incorporation of acetate-1-C14 into fatty acids and cholesterol by carcass and liver was determined 30 minutes after injection of the labeled acetate in mice grafted with adrenocorticotropin-secreting tumors. Serum cholesterol levels were also determined. Lipogenesis is elevated under fed and fasted conditions in mice bearing adrenocorticotropin-secreting tumors as compared with normal controls or tumor-bearing adrenalectomized mice. Cholesterologenesis was not significantly different in fed tumor-bearing and control mice. When fasted, however, the tumor-bearing mice exhibited greater incorporation of C14 than that of their controls. Fasting did not decrease cholesterologenesis in the former group. Serum cholesterol levels of the adrenocorticotropic mice were found to be twice as high as those of controls. In addition, the amounts of carcass and liver fatty acids were three times as great for the ACTH mice as compared with controls, although their body weights did not differ significantly. Carcass and liver cholesterol content of adrenocorticotropic mice was also elevated. The results of this experiment indicate that mice bearing adrenocorticotropin-secreting tumors exhibit a ‘metabolic’ type of obesity.
Metabolism of L-Thyroxine and L-Triiodothyronine in the Absence of the Liver
Authors: Flock Eunice V. , Bollman Jesse L. , Grindlay John H. , Orvis Alan L.
Published: December 2017

The total amount of I131-containing compounds excreted in the urine of the dehepatized dog receiving either radioactive thyroxine or triiodothyronine is similar to that of the normal dog receiving similar injections. The important role of the liver in the deiodination of thyroxine and triiodothyronine is indicated by the failure of the liverless animal to convert these compounds to inorganic iodide as completely as does the normal dog. Only a small percentage of the I131 compounds excreted by the liverless dog appears as inorganic iodide. The most abundant iodine compound in the urine of the dehepatized dog is a conjugate of thyroxine when thyroxine is injected, and an unidentified compound, b, when triiodothyronine is injected.
Periodicity in the Fecundity of Male Rabbits
Authors: Doggett Virginia C.
Published: December 2017

Semen specimens were collected daily from 13 rabbits for prolonged periods during the course of 13 months. Total sperm count rose to a definite peak every 2–7 days (av. = 3.16 days) and then decreased again to values of from 79% to less than 1% (usually about 50%) of the preceding peak. In mature animals, the frequency of peaks was significantly different from the random distribution and significantly similar among individual animals. In pubescent animals, the intervals between peaks were consistently either longer or shorter than those found in mature animals, but the intervals were significantly different from the random distribution. The peaks were found not to coincide in different animals and were therefore not due to environmental influences. The number of collections made each day did not affect the daily pattern of total sperm counts. As daily total sperm count rose and fell sperm motility and the volume of liquid semen rose and fell with it, but this was not the case with the amount of coagulated semen.
Renal Excretion of Radioiodide in the Dog
Authors: Giebisch Gerhard , MacLeod Martha B. , Kavaler Frederic
Published: December 2017

Radioiodide and creatinine clearances were measured simultaneously in dogs. Osmotic diuresis was induced by loading with mannitol, sodium salts of various anions such as chloride, bromide, iodide, nitrate and ferrocyanide, and by the administration of mercurial diuretics. Results of these experiments are compared with those obtained during water diuresis. No evidence for active tubular reabsorption of radioiodide could be observed. Renal tubular reabsorption of I131 was found to be chiefly determined by the degree of tubular water reabsorption and hence the transtubular diffusion gradient of radioiodide. Nonspecific effects of other anions in the tubular urine may modify passive tubular reabsorption: anions less readily reabsorbed displace I131 from the urine and depress its renal clearance. Indirect evidence suggests that about 95% of filtered radioiodide is reabsorbed at a tubular site proximal to that of final water reabsorption.
Effect of CO2 Exposure and Respiratory Acidosis on Adrenal 17-Hydroxycorticosteroid Secretion in Anesthetized Dogs
Authors: Richards John B. , Stein S. N.
Published: December 2017

Effect of CO2 exposure on adrenocortical function has been studied by measuring 17-hydroxycorticosteroids in adrenal venous blood of anesthetized dogs. In dogs exposed to 2.5%, 5% and 10% CO2 successively for 1 hour each, and 10%, 20% and 30% CO2 successively for 1 hour each, adrenocortical stimulation occurred in 10% of the total number of dogs exposed to 2.5% CO2, 40% of the animals exposed to 5% CO2, 75% of dogs exposed to 10% CO2 and in all dogs subjected to 20% and 30% CO2. Exposure to increasing concentrations of CO2 was accompanied by a progressively severe respiratory acidosis. Dogs exposed to 20% CO2 for 4 hours displayed a maximal adrenocortical stimulation within the first 15–30 minutes, and this marked response persisted for the remainder of the exposure period. The adrenocortical stimulatory response to 20% CO2 exposure is abolished by hypophysectomy. It is concluded that the pituitary adrenal stimulation occurring in anesthetized dogs exposed to CO2 is induced by one or more of the physiologic alterations attendant respiratory acidosis.
Separation of Hormonal Activities in the Anterior Pituitary by Ultracentrifugation
Authors: Brown J. H. U. , Hess Melvin
Published: December 2017

Partial separation of the hormones of the anterior pituitary of beef has been obtained by ultracentrifugation in the Spinco Model L Ultracentrifuge. Fresh and frozen glands were homogenized in 0.25 m sucrose and centrifuged at 500 x g to remove nuclear and cellular debris, at 6600 x g to obtain mitochondria, at 11,150 x g to obtain acidophiles, and at 80,000 x g to obtain basophiles. Each fraction was analyzed for nitrogen, for PNA and for hormonal content. Most of the nitrogen was obtained in the supernatant, most of the PNA in the acidophil granules, and the activity was partially separated. In general the mitochondria contained growth hormones, acidophil granules contained ACTH, supernatant contained FSH, and TSH and LH were found in both acidophil and basophil granules.
Comparison of Some Enzyme Systems in Normal and Thyrotoxic Rat Livers
Authors: Maley Gladys Feldott
Published: December 2017

The activity of the following enzymes and enzyme systems have been shown to increase above the normal in the mitochondria from thyrotoxic rats' livers: over-all glutamate oxidation, succinoxidase, cytochrome oxidase, cytochrome c, and adenosine triphosphatase. During hypothyroidism the activity of these enzymes decreases. Mg++ ion concentration was not influenced by the thyroid hormone. The latent ATPase4 of thyrotoxic rat liver mitochondria is activated by shorter preaging periods at 37° than that of normal. In a whole homogenate of these same tissues the glucose-6-phosphatase activity, inorganic phosphate content and apparent protein level was also increased during thyrotoxicity.
Inactivation of Insulin by the Isolated Liver of the Bullfrog
Authors: Weisenfeld Shirley , Jauregui Raul Hernandez , Goldner Martin G.
Published: December 2017

Experiments are presented in which insulin solutions were perfused through isolated frog livers in order to study the inactivation of this hormone by liver tissue. The solutions were recirculated many times and aliquots were tested biologically at various intervals for hypoglycemic activity. While insulin retains its activity after a single frog liver perfusion, it is gradually inactivated with increasing numbers of reperfusions. This result is in accord with the inactivation of insulin by liver slices and liver brei as reported by others. The relatively slow inactivation of insulin when perfused through the isolated frog liver is in contrast to the inactivation of glucagon which, as previously reported, loses its hyperglycemic activity after a single perfusion through this preparation. The general significance of this finding is discussed.
Effects of Feeding a Diet Containing Lactose Upon ß-d-Galactosidase Activity and Organ Development in the Rat Digestive Tract
Authors: Fischer Jessie E.
Published: December 2017

Feeding a 25% lactose diet had no enhancing effect upon rat stomach or pancreas development or upon ß-d-galactosidase activity in stomach lining or pancreas. The lactose feeding significantly increased the cleaned small intestine fresh weight and total nitrogen. This increase in total nitrogen appeared to be due mainly to growth of the mucous epithelium, since the nitrogen content was significantly increased in the epithelium but not in the rest of the small intestine. The total ß-d-galactosidase activity of the small intestine mucous epithelium was significantly increased by the lactose feeding, but the specific activity (units of enzyme per milligram of tissue nitrogen) was not significantly altered.
Effects of Altered Acid-Base Balance on Adrenocortical Function in Anesthetized Dogs
Authors: Richards John B.
Published: December 2017

Effect of altered acid-base balance, induced by the intravenous infusion of either hydrochloric acid or sodium bicarbonate, on adrenocortical function in anesthetized dogs was studied. The secretory activity of the adrenal cortex was determined by measuring 17-hydroxycorticosteroids in adrenal venous blood. Adrenocortical stimulation occurred in dogs with a profound decrease in arterial ph and bicarbonate concentration in the presence of a normal arterial CO2 tension (acid infusions) and in dogs with increased arterial CO2 tension and bicarbonate concentration in the presence of a normal arterial ph (bicarbonate infusions). It is concluded that concomitant alterations in both arterial ph and CO2 tension are not required to initiate an adrenocortical response, and it is suggested that a suitable change in either of these factors may act as a pituitary-adrenocortical stimulus.
Gastric Secretory Response to Various Amounts of Food (Dose-Response Curve)
Authors: Ivy A. C. , Lin T. M. , Langberg G.
Published: December 2017

Evidence was obtained showing that in making comparative studies on gastric secretion the glands should be secreting no free acid. In the Heidenhain pouch dogs there was an optimum sized meal for an optimum secretory response during the first hour, more secretion having been obtained with a 300 gm. meal than a 900 gm. meal. The time of the occurrence of the peak of the hourly secretory output was related to the size of the meal in the Heidenhain and the transplanted (Ivy) pouch dog. A definite sigmoid dose-response curve was obtained in the dog with a transplanted pouch. In two Heidenhain pouch dogs a complete sigmoid dose-response curve was not obtained because with a large meal of 900 gm. the voluntary volumetric capacity of the main stomach was reached before the secretory capacity of the pouch was approached. A complete sigmoid curve could be obtained only with a small Heidenhain pouch. In the linear portion of the dose-response curve in both types of pouches doubling the size of the meal roughly doubled the secretory response.
Relation of Posttetanic Potentiation to Subnormality of Lateral Geniculate Potentials
Authors: Evarts Edward V. , Hughes John R.
Published: December 2017

The lateral geniculate response to electrical stimulation of the optic nerve was recorded in decerebrate cats and in cats anesthetized with Nembutal. Tetanization of the optic nerve at 500/sec. for 20 seconds in nembutalized cats produced a prolonged second subnormality of the geniculate postsynaptic response. Further tetanization during tetanically-induced second subnormality produced posttetanic potentiation (PTP). The degree of PTP (expressed in percentage of the pretetanic level) of the postsynaptic response following a 20-second tetanus was proportional to the degree of second subnormality present at the time the tetanus was applied. PTP was also found to occur during the subnormality which followed a brief train of optic nerve shocks, and during LSD-induced subnormality. PTP of postsynaptic lateral geniculate potentials occurred only rarely in the absence of some form of intentionally induced subnormality.
In Vitro Formation of αß-Unsaturated Ketones by Adrenal Tissues in Ascorbic Acid Deficiency
Authors: Bacchus Habeeb
Published: December 2017

In vitro studies on the formation of Δ4-3-ketones from the Δ5-3 ß-ol structure of dehydroepiandrosterone acetate by adrenal tissue were conducted. The adrenal tissue of normal and control guinea pigs is capable of this conversion to the extent of 0.46 µm/100 mg adrenal tissue, in the absence of any added cofactors. The conversion by adrenals of ascorbic acid-deficient animals is significantly less than this and is decreased progressively with the duration of the scorbutigenic fare. Addition of ascorbate to the incubation preparation corrects the disturbance in this process in the adrenal of the ascorbic acid-deficient animal.
Failure to Show Supersensitivity to l-Epinephrine and l-Norepinephrine in the Chronic Denervated Heart in Unanesthetized Dogs
Authors: Greenberg Ruven , Lambeth Charles B.
Published: December 2017

In the unanesthetized chronic denervated heart dog graded i.v. doses of l-epinephrine have a different pattern of circulatory effects depending upon whether they are given by quick injection or by infusion. Quick injections of l-epinephrine occasionally caused heart rate decreases and b.p. decreases; with the infusions these effects became frequent. By comparison, l-norepinephrine invariably affected heart rate and b.p. increases. Further, l-norepinephrine was a better positive chronotropic agent than l-epinephrine by roughly 100% and the durations of the chronotropic and pressor effects were lengthened. Three of four of the denervated heart dogs did not become supersensitive to either agent by any criterion. In the fourth dog there was a slight and roughly equal chronotropic sensitization which was insignificant in extent and without marked differential as compared to other denervated structures. Thus the data, while not conclusive, does not lend support to any of the theories wherein one or the other of these agents is regarded as the chief sympathetic mediator.
Eosinophil Levels of the Turtle After Exposure to Cold and Epinephrine
Authors: St. John Richard , Nardone Roland M.
Published: December 2017

The effect of cold exposure, epinephrine injection, and a combined cold-epinephrine treatment on the eosinophil level of the turtle, Pseudemys elegans, was studied in order to ascertain information regarding the sensitivity of the endocrine and nervous systems of a poikilotherm to stresses. A low temperature environment produced an eosinopenia; the average fall was 34.8% below the control level. Epinephrine injection resulted in an eosinophilia; the average rise was 37.4% above the control level. Combined treatment with cold and epinephrine resulted in an eosinopenia; the average fall was 32.8% below the control level. It is concluded that the turtle shows an endocrine response to cold stress.
Tissue Responses in the Cold-Exposed Rat
Authors: Weiss A. Kurt
Published: December 2017

Ten to fourteen-week-old rats were exposed to 5 ± 2°C for 5 days. The Qo2 values of liver, diaphragm, heart and skeletal muscle were elevated; kidney slices gave a variable response; preparations of thymus, testis, brain, spleen, intestinal smooth muscle and lung did not show significant alterations in oxygen consumption. Comparison of these findings with Barker's data concerning the effects of thyroxine injections in vivo reveals that in general the tissues respond in the same way to the cold stimulus and to the hormonal treatment. In hypothyroid animals, the unresponsive tissues listed above do not undergo alterations in oxygen consumption, but diaphragm and heart Qo2 values are significantly reduced, while liver and kidney oxygen consumption rates are slightly decreased. The survival time of hypothyroid animals is reduced in the cold; 5 days after exposure of the hypothyroid animals to cold, heart and liver Qo2 values were found to be elevated, but not to the extent demonstrated by tissues taken from euthyroid animals. The hypothesis is advanced that the thyroid gland exerts its effects by way of a few selected tissues only, in which it regulates the level of metabolism so as to provide adequate heat production for suitable adaptation to cold of the entire animal.
Effects of Pituitrin and Cold on Water Exchanges of Frogs
Authors: Hong Suk Ki
Published: December 2017

Net water transfer across the skin and urine formation by the kidneys were studied in frogs ( R. pipiens) especially under the influence of Pituitrin. The water uptake across the skin increased approximately 2.5-fold after the injection of Pituitrin, without any accompanying increase in urine formation. This Pituitrin effect in intact frogs was abolished totally or partly in extreme cold (1°C) or when the frogs were treated with nitrogen or KCN or IAA. These results are interpreted as evidence that the increase of net water transfer across the frog's skin after the application of Pituitrin might be an active process, and it may be further postulated that the energy requirement for this increased transfer is small.
Effects of Carbon Dioxide, Epinephrine and Ilidar on Skin, Blood and Rectal Temperatures of Unanesthetized Dogs Exposed to Extreme Cold
Authors: Good A. L. , Sellers A. F.
Published: December 2017

Polyethylene cannulae were surgically placed in the pulmonary artery and in the posterior vena cava at a point where the hepatic veins enter (referred to as ‘hepatic vein’). Thermistors mounted in polyethylene tubing, were passed through these cannulae and the temperature changes of blood, skin (thorax, forearm, paw) and rectum were recorded photographically. The effects of carbon dioxide, epinephrine and Ilidar were superimposed on extreme cold while continuously recording blood, rectal and skin temperatures. Carbon dioxide inhalation was associated with a fall in blood and rectal temperatures and marked diminution of shivering. Little effect on skin temperatures was noted. It was thought that the decrease in metabolism contributed to the fall in ‘core’ temperature. Epinephrine, given intravenously in doses of 2.5 µg/kg was associated with an immediate cessation in shivering which persisted for 1–3 minutes. Blood and rectal temperatures fell slightly; skin temperatures showed little change. The intravenous administration of Ilidar in doses of 4.0 mg/kg was associated with rather marked rises in blood and rectal temperatures which were additive to those resulting from exposure to cold. Skin temperatures were only slightly affected. Apparently the doses of Ilidar were too small to block cutaneous vasoconstriction induced by sympathetic impulses reaching the cutaneous vessels. Vasodilation in the viscera could result in shunting blood away from the skin and in this way increase internal temperatures.
Thyroidal Iodine Metabolism in Inbred and F1 Hybrid Mice
Authors: Chai C. K. , Amin A. , Reineke E. P.
Published: December 2017

Thyroidal iodine metabolism was studied in four inbred strains of mice and two groups of F1 hybrids by use of radioiodine. Significant strain differences were found in both the 48-hour thyroidal retention of I131 and its output rate constant. Three closely related groups studied were C57BL/6, C57BR/cd and BBF1, their F1 hybrid. The other three groups included A/Jax, BALB/c and CAF1, their F1 hybrid. C57BL/6 mice had a significantly faster output rate and lower 48-hour I131 retention than any other group. The first three groups listed had a more rapid output rate and lower 48-hour retention than the last three. In intergroup comparisons and inverse relationship between I131 output rate and 48-hour retention was clearly shown. The results indicate that in mice pituitary TSH output, as indicated by thyroidal I131 output rate and thyroidal iodine pool size, is controlled by separate genetic factors.
Mechanisms of Desoxycorticosterone Action. XII: Influence of the Thyroid
Authors: Salgado E. , Green D. M.
Published: December 2017

The effect of the thyroid on the development of DCA hypertension was studied by comparing the behavior of DCA-treated thyro-parathyroidectomized rats with DCA-treated controls. Thyro-parathyroidectomy prior to implantation of a single 20-mg DCA pellet prevented hypertension and all tissue lesions except periarteritis nodosa, during a 15-week period in which the animals slowly matured. Subsequent administration of minimal doses of thyroxine (insufficient to restore the histological picture of the hypophysis completely to normal) was associated with the development of hypertension and cardiac hypertrophy, although the growth rate was not materially accelerated. It was concluded that the thyroid hormone may represent a significant factor in the development of DCA hypertension. The ability of DCA to induce periarteritis nodosa without hypertension in the thyro-parathyroidectomized rat suggests that this preparation may offer a new approach to studies of the pathogenesis of periarteritis.
Effects of Feeding Diets Containing Lactose, Agar, Cellulose, Raw Potato Starch or Arabinose on the Dry Weights of Cleaned Gastrointestinal Tract Organs in the Rat
Authors: Fischer Jessie E.
Published: December 2017

Purified diets containing 25% lactose, agar, wood cellulose or raw potato starch, or 10% arabinose were compared with a control diet containing cornstarch as the only carbohydrate for effects upon dry weights of cleaned gastrointestinal organs in rats. Many effects of diets upon absolute organ weights and upon organ weights relative to body weight were found. When the lactose diet was fed for 1 week from weaning, the relative small intestine weight and the absolute and relative weights of both the cecum and the colon plus rectum were increased over the controls. When all of the diets were fed for 4–5 weeks, organ weights were increased by diets as follows: relative stomach weight by agar and cellulose, absolute and relative small intestine weights by lactose, relative small intestine weight by arabinose, absolute and relative cecum weights by all experimental diets except cellulose, and absolute and relative colon plus rectum weights by all five experimental diets. Thus, stomach growth is affected by diet little or not at all, while intestine growth is differently affected in its different regions by various diets. Increases in dry weights or numbers of fecal pellets were not at all related to increases in small intestine or cecum weight, and were not well related to increases in colon plus rectum weight. Using these facts and knowledge of certain properties of the various substances, certain ideas as to modes of action of diets in producing the observed changes were excluded.
Effect of X-Irradiation on Myoglobin Content
Authors: Faulkner Willard R. , Blood Frank R.
Published: December 2017

To assess the effects of x-irradiation on myoglobin concentration, rats were irradiated with an ld50/30 dose of x-irradiation. Each irradiated rat was paired with a control animal. At approximately weekly intervals for 5 weeks, several pairs were killed and a portion of their skeletal muscle was assayed for myoglobin. No change in the myoglobin concentration was observed although a severe anemia developed in all of the irradiated animals.
Effect of Adenosine on Phosphofructokinase Activity of Preserved Blood
Authors: Brownstone Y. S. , Blanchaer M. C.
Published: December 2017

Adenosine in concentrations of 5–20 mm prevents the progressive decrease in activity of the erythrocyte glycolytic enzyme phosphofructokinase in blood preserved in acid citrate-dextrose at 4°. In hemolysates the protective effect of adenosine is also exhibited by its metabolic derivatives inosine, ribose-5-phosphate and adenosine triphosphate. The beneficial effects of adenosine on in vivo survival of stored red cells, glycolysis and PFK activity suggests that the integrity of this enzyme may influence the keeping qualities of ACD preserved blood.
Time Course of Active Amylase Accumulation by Rat Submaxillary Gland During Continuous Pilocarpine Stimulation
Authors: Schneyer Charlotte A. , Schneyer Leon H.
Published: December 2017

Administration of pilocarpine for varying periods results in a continuous orderly increase in the amylase levels of rat submaxillary glands without prior depletion or accompanying appreciable changes in gland wet weight. This amylase increase with time appears to occur in two phases: the first phase is characterized by a possible brief initial lag followed by a period of logarithmic increase leading to a plateau within 90 minutes. A second phase of rapid rise occurs within 3 hours. The S-shaped curve of the first phase suggests the time course of an autocatalytic process and may indicate a) synthesis, or b) activation of a precursor or bound enzyme form. Sodium oleate, urea, trypsin, n-butanol, heat and ph activate precursors of other enzymes but neither activated nor significantly inhibited amylase of gland homogenates. Atropine in vivo effected complete inhibition of the pilocarpine-induced amylase accumulation. Amylase accumulation under these conditions suggests enzyme synthesis.
Electrical and Vascular Concomitants of Spreading Depression
Authors: Van Harreveld A. , Ochs Sidney
Published: December 2017

Spreading depression is accompanied by a slow potential change, a drop in cortical conductivity and by vascular changes. The latter were investigated in histological preparations of cortex frozen while a spreading depression was in progress. In the cat and rabbit a broad wave of vasodilatation was observed. In the rabbit this appeared to be preceded by a narrow region of vasoconstriction. Spreading depression can be changed into spreading convulsive activity by administering CO2 in the respiratory air (7–12%). CO2 markedly decreased the drop in cortical conductivity but affected the magnitude of the slow potential change only moderately. It is postulated that both the conductivity drop during spreading depression and a similar drop observed after asphyxiation of the brain are caused by a transport of ions from the intercellular compartment into cortical cellular elements. The relationship between the slow potential change, conductivity drop, vascular changes and the changes in the electrocorticogram during spreading depression is discussed.
Effect on Urinary Bladder of Unilateral Stimulation of Pelvic Nerves in the Dog
Authors: Ingersoll Everett H. , Jones Louise L. , Hegre Erling S.
Published: December 2017

In dogs anesthetized with sodium pentobarbital, unilateral stimulation of intact pelvic nerves or of their distal cut ends, with or without section of the hypogastrics, and at various frequencies and intravesical pressures, always produced prompt and vigorous contractions in all regions of the corresponding side of the viscus. On the contralateral side the responses were weaker, more variable and, in general consisted of several types: a) prompt and vigorous contractions similar to those observed on the stimulated side; b) slightly delayed contractions which were also similar to those obtained on the homolateral side; c) contractions preceded by relaxations; d) relaxations of the detrusor which persisted for the duration of the stimulation; e) isolated segments of the viscus which were totally unresponsive to stimulation. The responses obtained in dogs following unilateral stimulation of pelvic nerves were similar in most respects to those observed previously in cats.
Temperature Effects on Radiocolloid Uptake by the Isolated Rat Liver
Authors: Brauer Ralph W. , Holloway R. J. , Leong George F.
Published: December 2017

Effect of temperatures between 20° and 38°C on the relation between blood flow and CrPO4 colloid uptake by the isolated rat liver has been studied. The Q10 for the over-all reaction rate is substantially constant and equal to 1.92 over this range. Theoretical limitations prevent the unambiguous interpretation of this value as a measure of the Q10 of the basic uptake reaction. Hemodynamic data indicate that cooling affects liver blood flow and liver blood distribution primarily, but not exclusively, through increasing blood viscosity. Evidence pointing to possible vasorelaxation under these conditions is mentioned. The application of these results to measurements of liver blood flow in hypothermia in vivo is discussed and the required diagram relating hepatic blood flow with the product of CrPO4 extraction efficiency and hepatic blood flow for the rat is presented.
Relative Value of Cysteamine and Cystamine as Radioprotective Agents for Fetal and Adult Mice
Authors: Rugh Roberts
Published: December 2017

The —SH compound cysteamine and its —SS product, cystamine, have been tested as protective agents against x-irradiation death for adult CF1 mice of both sexes, and also the 15.5–17.5-day fetuses of the same strain. Control fetuses of 15.5–17.5 days rarely survived x-irradiation to 600 r or more while those whose mothers were injected with cysteamine prior to irradiation could tolerate 700-r x-rays and the majority of offspring survived 30 days postparturition. When irradiated fetuses were given foster (normal) mothers at birth, survival was further improved, but only in those whose mothers were given the drug just prior to irradiation. Cystamine also gave protection to the fetuses. Optimum survival of controls exposed at 17.5 days to 700-r x-rays was 19% at 30 days, while those ‘protected’ by cysteamine showed 50% survival and with cystamine, 41% survival. Thus there was definitely fetal ‘protection’ by either drug. Adult males and females of the same strain showed considerable ‘protection’ by either drug, the males increasing survival from 2% to 30% (cystamine) and 34% (cysteamine) while the females showed increased survival value to 56% and 64%, respectively. It is apparent that both of these drugs have protective value for fetal and adult mice of both sexes, when they are exposed to the ld50/30-day level of x-rays.
Effects of Carbohydrate Feeding on Serum Lipids and Lipoproteins in the Rat
Authors: Bragdon Joseph H. , Havel Richard J. , Gordon Robert S.
Published: December 2017

Fasting in the rat is accompanied by an increase in serum cholesterol concentration reflecting an increase in high-density lipoproteins. The feeding of carbohydrate results in decreases in both low- and high-density lipoproteins, the former occurring acutely, and the latter occurring more slowly. In the fasting rat the injection of protamine, an antiheparin agent, produces an increase in all serum lipids, but the increase occurs in the low-density lipoproteins. In the rat fed carbohydrate this lipemia-inducing effect of protamine is practically abolished. The feeding of carbohydrate has no effect, however, on the rate of clearance of intravenously administered chylomicrons. These phenomena are discussed in relation to current theories of lipid transport.
Carbohydrate Metabolism During Fasting and Hibernation in the Ground Squirrel
Authors: Zimny Marilyn L. , Tyrone Victor
Published: December 2017

Biochemical levels of glycogen, lactate and pyruvate determined in liver, skeletal muscle and cardiac muscle of control, fasting and hibernating groups of ground squirrels were compared. During fasting liver glycogen increased, as compared to the control, apparently as a result of glycolysis in both skeletal and cardiac muscle. The lactate-pyruvate ratio in both types of muscle greatly favored lactate. Therefore, it is possible that the formation of a ‘lactate pool’ by muscle supplies the glycogenetic needs of the liver at this time. In hibernation both liver and cardiac muscle showed increases in glycogen over control values. Possibly, this may subsequently serve as a source of energy for arousal. Lactate and pyruvate during hibernation decreased in all tissues studied due to a low metabolic rate slowing the process of glycolysis. However, the ratio between the two compounds remained within the control range. The data suggest that the mechanism of carbohydrate metabolism during fasting differs from that during hibernation.
Acetate Metabolism in Experimental Virus-Induced Disease
Authors: Siegel Benjamin V. , Hughes Ann M. , Tolbert Bert M.
Published: December 2017

The influence of experimental poliomyelitis on the oxidative metabolism of acetate by mice was studied employing an apparatus designed to measure respiratory radioactivity excretion. The mice were given sodium acetate-2-C14 and the excretion of breath C14O2 measured over a 7-hour period. Animals infected with poliomyelitis virus oxidized acetate at a one-third lower peak rate initially following administration of substrate. After 7 hours, about 5% more total C14O2 was excreted by mice manifesting paralytic symptoms of central nervous system involvement than by normal mice. This lack of any large effect is of particular interest considering the changes in physiological conditions associated with paralytic poliomyelitis.
Evidence That Histamine is a Gastric Secretory Hormone in the Rat
Authors: Schayer Richard W. , Ivy A. C.
Published: December 2017

One test on each of six chronic gastric fistula rats was made in which after a 12-hour fast C14 l-histidine was injected subcutaneously. Twenty-four hours later, while still fasting, aminoguanidine HCl (AG) (2 mg of the base), a powerful diamine oxidase inhibitor (an antihistaminase), was given hourly subcutaneously through an indwelling needle day and night for 3 additional days. Twenty-four hours after the start of AG, food was given for 12 hours; fasting then occurred for two 12-hour periods, and then food was given again for 12 hours. The average urinary C14 histamine counts per minute during the various AG periods were: first AG control period, 105; second AG control period, 104; 12-hour feeding period, 185; first 12-hour postfeeding-fasting period, 157; second postfeeding-fasting period, 68; final 12-hour feeding period, 106. It is concluded that, on feeding, C14 histamine was released in quantities adequate to stimulate gastric secretion when aminoguanidine was present to prevent histamine destruction.
Pyriform Responses to Electrical Stimulation of Olfactory Fila, Bulb and Tract
Authors: MacLean Paul D. , Rosner Burton S. , Robinson Franklin
Published: December 2017

Single shock stimulation of the olfactory fila in anesthetized animals evokes slow potentials from the olfactory bulb and pyriform cortex. Conduction velocity in the fila is estimated at 0.4 m/sec. Repetitive electrical stimulation of fila, bulb or tract, produces four phenomena in the pyriform cortex: a) gradual recruitment with low frequency stimulation (3–30/sec.); b) alternation in size of evoked responses at frequencies of 6/sec. and above; c) decline in amplitude of responses with frequencies above 20/sec. (‘decrementation’); and d) posttetanic potentiation after stimulation of the olfactory bulb or tract. Potentiation may persist for several minutes following tetanization of the tract. Recruitment and decrementation are observed in the bulb also upon stimulation of the fila.
Inverse ‘Conditioning’ by Hypophysectomy of Mineralocorticoid and Glucocorticoid Activities of 9[α]-Chlorocortisol
Authors: Ventura Joaquin , Selye Hans
Published: December 2017

9[α]-chlorocortisol acetate [Cl-COL-Ac] induced a syndrome of hyalinosis (nephrosclerosis, myocarditis, polyuria, edema, etc.) in rats conditioned for mineralocorticoid overdosage by unilateral nephrectomy and NaCl supplements. Hypophysectomy protected the animals against the development by Cl-COL-Ac of this syndrome, but, at the same time, predisposed them to the production of severe necrotizing pulmonary lesions. Apparently, the absence of the hypophysis can simultaneously condition tissue responses, positively to some, and negatively to other actions of the same corticoid molecule.
Influence of a Protein-Free Diet on the Immediate and Latent Effects of Stilbestrol
Authors: Glasser Stanley R.
Published: December 2017

The absence of protein from the diet of stilbestrol-treated rats modified, largely quantitatively the response to the hormone. Stilbestrol, per se, induced a body weight loss which was greater in the protein-depleted than in the protein-fed animal. Recovery on an adequate protein diet, after withdrawal of the hormone permitted an immediate recouping of body weight losses, whereas animals on the protein-deficient diet did not recover body weight losses. Stilbestrol administration increased excretion of nitrogen indirectly by restriction of food intake. This nitrogen loss was augmented by protein depletion. The marked retention of nitrogen by animals recovering on an adequate diet was more pronounced in the treated animal but rats continued on the protein-deficient diet maintained a negative nitrogen balance. The absence of protein from the diet diminished the anticatabolic influence of stilbestrol on total liver protein. Recovery on the basal diet allowed the repletion of liver protein but further decreases in liver protein concentration followed recovery on the deficient diet. A marked increase in the concentration of liver fat appeared concomitantly with the progressive depletion of liver protein in both treated and untreated groups.
Phagocytosis of Foreign Red Blood Cells by the Reticulo-Endothelial System
Authors: Halpern Bernard N. , Biozzi G. , Benacerraf B. , Stiffel C.
Published: December 2017

The clearance rate of nucleated pigeon erythrocytes injected intravenously into mice and rats has been calculated either by routine differential red cell counts or by measuring the radioactivity of the erythrocytes tagged with P32. Histological evidence is given that the foreign erythrocytes are phagocytized by the reticulo-endothelial cells of the liver and spleen. The clearance rate of the foreign erythrocytes, which measures the speed of the phagocytosis, follows in mice a regular exponential function similar to this previously established for other colloids. No spontaneous antibodies to pigeon erythrocytes could be detected in mice. The rapid and complex clearance rate of pigeon erythrocytes observed in rats is related to the existence of spontaneous specific antibodies. The simultaneous injection of pigeon erythrocytes and of India ink into mice, both phagocytized by the RE cells, results in a competition between the two substances in favor of the smaller particles of carbon.
Increased Renal Reabsorption of Osmotically Free Water by the Toad (Bufo marinus) in Response to Neurohypophysial Hormones
Authors: Sawyer Wilbur H.
Published: December 2017

Neurohypophysial extracts or dehydration produce a pronounced antidiuresis in Bufo marinus. The antidiuretic mechanism was studied by following creatinine, inulin and free-water clearances in unanesthetized toads. Urine was collected directly from the ureters to avoid errors due to water reabsorption through the bladder. A decrease in free-water clearance is a consistent feature and accounts for most of the antidiuresis. There may also be a decrease in filtration rate. The effect of neurohypophysial hormones on free water excretion is attributed to an increase in the permeability of the tubule to the osmotic inflow of water. The similarity between the action of neurohypophysial hormones on the skin, the bladder and the renal tubule of Amphibia suggests a common mechanism, namely the dilatation of pores. The hypothesis is also advanced that the antidiuretic action of neurohypophysial hormones on the mammalian kidney depends on the same mechanism.
Factors Influencing the Gastric Secretion of Dyes
Authors: Ray Francis E. , Pease Patricia
Published: December 2017

Gastric secretion of six dyes, thionin, Nile blue A, pyronine B, toluidine blue, methylene green and neutral violet was studied in guinea pigs. The highest values are given by neutral violet; the lowest by thionin. The degree of secretion is related to the basicity of the dye, provided that the dye is secreted in its original form. There is a possibility that the diffusion coefficient may be of significance.
Effects of Carbon Dioxide on Deep Structures of Temporal Lobe of the Brain in the Marsupial Phalanger
Authors: Dunlop Colin W.
Published: December 2017

The effects of inhalation of 10% and 30% CO2 on the evoked potentials from the fornix-hippocampal system in the marsupial phalanger were determined. The spontaneous and evoked activity of this system is depressed by CO2, with the dorsal hippocampus apparently more susceptible than the ventral hippocampus, especially where the evoked potentials from stimulation of the fornix were recorded in the region of the hippocampal pyramidal cell layer.
Lipid and Cholesterol Content of Hepatic Lymph in Experimental Nephrosis
Authors: Friedman Meyer , Rosenman Ray H. , Byers Sanford O.
Published: December 2017

The lipid and cholesterol content of hepatic lymph, a diffusate of plasma, was determined in nephrotic rats during both the induction and the developed stages of experimental nephrosis. Despite the occurrence of hypercholesteremia and hyperlipemia in such rats, their hepatic lymph was found to contain a normal content of cholesterol and a greatly reduced content of total lipid. These results suggest that in the nephrotic state an intravascular alteration occurs in the various lipid fractions of plasma that interfere with their normal rate of egress from plasma.
Effect of Tumbling Trauma on in Vivo Acetate-2-C14 Metabolism in Rats
Authors: Koltun Walter L. , Gray Irving
Published: December 2017

The effect of tumbling trauma on the in vivo aerobic carbohydrate metabolism of normal and traumatized rats has been investigated through the ability of individual organs to convert acetate-2-C14 to nonvolatile metabolites. The ability of the brain and heart to metabolize the acetate presented to their organs is not impaired. However, the ability of the liver to do this is very markedly impaired, the muscle less so and the kidney intermediate between the latter two. By following the changes in the specific activity, it has been shown that the ability of these organs to convert citrate to succinate to malate is unaffected. It is postulated that the block in the aerobic cycle may be in either the condensing enzyme or the acetyl-Co-A kinase.
Erythropoietic Response to Hypoxia as a Function of Age in the Normal Male Rat
Authors: Garcia Joseph F.
Published: December 2017

The labeled red cell volume technique was used to determine the erythropoietic response to an hypoxic stimulus in groups of male rats of various ages from 5 to 250 days. Whereas rats of 50 days of age or older responded well erythropoietically to the hypoxic stimulus, rats of 5–30 days of age show no statistical increase in total red cell volume or total hemoglobin when exposed to this stimulus. The inability of the young rat to respond to an hypoxic stimulus is here given as evidence of the high rate of red cell production existing in this animal. Further, it is postulated that the relative daily red cell production in these young animals is at a maximal or near maximal level.