bluuebunny/crossref_metadata_2025 huggingface dataset:
Antiadrenergic and Antihistaminic Therapy in Hemorrhagic Shock in Dog and Rat
Authors: Jacob S. , Friedman Edward W. , Levenson Sabin , Glotzer Philip , Frank H. A. , Fine J.
Published: December 2017

The influence of pretreatment with dibenamine on the development and course of hemorrhagic shock, and the effect of treatment with dibenamine, rapidly acting antiadrenergic drugs, or antihistaminic drugs after hemorrhagic shock had been allowed to become unresponsive to replacement transfusion, were tested in dogs prepared in advance to permit measurement of portal-caval venous pressure gradient. Preliminary dibenamine administration was also tested in rats submitted to hemorrhagic shock. The conclusions were as follows: 1) The protective effect of dibenamine prior to the induction of hemorrhagic shock in the dog consists mainly of a reduction of the bleeding volume. Intrahepatic vasoconstriction is not reduced. A dog which is not under the influence of dibenamine can tolerate a greater degree of blood loss than a dibenaminized dog. After hemorrhagic shock has been allowed to become refractory to replacement transfusion, antiadrenergic and antihistaminic drugs do not reduce intrahepatic vasoconstriction or increase the survival period or the survival rate. 2) Dibenamine given prior to hemorrhage enables the rat to survive a degree of blood loss which is lethal to the untreated rat. This, in part, appears to be due to better blood flow to the respiratory center.
Influence of Moderate Changes in Blood Volume on Urine Flow
Authors: Zuidema George D. , Clarke Neville P. , Reeves Johnie L. , Gauer Otto H. , Henry James P.
Published: December 2017

Increased filling of thoracic circulation produces a diuresis, while decreased thoracic filling causes oliguria. The validity of an hypothesized volume regulating mechanism can be tested by altering circulating blood volume by isotonic infusions or venesection without altering blood osmolarity. Normal saline, iso-oncotic bovine albumin and canine plasma infusions are followed by diuresis. Hemorrhage induced an oliguria in every experiment. In 18 of 26 experiments, whole blood infusions produced diuresis. In eight of 26 experiments, whole blood infusions produced either no change in urine flow or an antidiuresis. Donor blood under certain circumstances contains antidiuretic substance which modifies the recipient's response to increased blood volume. Rat assay for antidiuretic hormone supports this hypothesis.
Formation and Binding of Histamine by Free Mast Cells of Rat Peritoneal Fluid
Authors: Schayer Richard W.
Published: December 2017

Suspensions of the cells of rat peritoneal fluid have a marked ability to decarboxylate C14 l-histidine and bind the resulting histamine in stable form. The evidence is strong that this activity is due almost entirely to mast cells; these constitute about 4% of the total number of cells present. The effects of temperature, time, and ph on this process were found to be characteristic of enzymic reactions. Preincubation of cell suspensions with nonisotopic histamine had no effect on the formation and binding of C14 histamine; this is evidence that exogenous histamine cannot enter the bound condition in free mast cells. The effects of histidine analogs on binding is described. Disruption of the mast cells results in a considerable loss in histamine forming activity. However, a fairly stable, soluble histidine decarboxylase can be obtained from the disrupted cells. A new method for determination of histamine as the S35 dibenzenesulfonyl derivative is described.
Some Effects of Ergotamine Tartrate Upon Lactation in the Rat
Authors: Grosvenor Clark E.
Published: December 2017

A study was made of the direct effects of ergotamine tartrate upon the lactating rat, her young, and upon milk secretion from her mammary glands. The drug was administered to lactating rats at dosage of 3 mg/kg/day on each of days 9–12 postpartum. It was found not to affect volume of milk in the mammary gland as measured by lactose content of mammary tissue on day 12 nor was it found to have altered the histological appearance of the gland. There is, however, significant loss in weight of the mothers during period of treatment correlated with significant reduction in food consumption. Recovery in weight occurs by the end of lactation. There is also significant weight loss of litters of treated rats during the same period although they suck more frequently during period of treatment than do controls. The possible significance of this is discussed.
Spinal Unit Activity During Synchronization of a Convulsive Type (Strychnine Tetanus)
Authors: Terzuolo Carlo A. , Gernandt Bo E.
Published: December 2017

Single unit activity during convulsive synchronized discharge and the relationship between unit activity and slow ‘waves’ were studied in the spinal cord of the decerebrate cat after intravenous injection of strychnine. Steel needle microelectrodes were used. Units did discharge in burst (from 1 to 5 impulses) only in coincidence with the slow oscillatory potential (tetanic ‘waves’). The firing is confined to the rising phase of this potential. Changes in d.c. state related to a convulsive activity were also studied. A relationship was found between frequency of the tetanic rhythm and d.c. state of spinal structures. The mechanisms of synchronization and rhythmicity of the convulsive activity in a population of neurons are discussed in connection with the problem of interaction between units.
Relationship of Total Peripheral Resistance to the Pressure Gradient From the Arteries to the Veins
Authors: Guyton Arthur C. , Lindsey Arthur W. , Armstrong George G.
Published: December 2017

The relationship of total peripheral resistance to the pressure gradient between the arteries and the veins has been studied in 59 dogs by three different methods. Some measurements were made in live dogs with normal vasomotor tone, and others were made in dead dogs with all vasomotor tone eliminated. The total peripheral resistance of the systemic circulation increases progressively as the pressure gradient decreases, which is the same effect that has been noted many times previously in isolated vascular beds. The resistance to blood flow at each respective pressure was one-fifth to one-seventh as great in the dog with normal vasomotor tone as in the dead dog without any vasomotor tone. The results obtained in this study were consonant with the concept of ‘critical closing pressure’ but also could be explained by simple elastic stretch of the vascular walls without assuming absolute ‘critical closure’ of the vessels.
Lysis of Dog Erythrocytes in Mildly Alkaline Isotonic Media
Authors: Waddell William J.
Published: December 2017

Dog erythrocytes undergo hemolysis in any isotonic medium with a value of ph higher than 7.6. The higher the value of ph, the more rapidly and the more completely hemolysis occurs; at ph 7.6 about 2 hours are required for noticeable hemolysis either in vivo or in vitro. This phenomenon does not occur with the erythrocytes of man, cat, mouse, guinea pig, rabbit, sheep, horse or ox. The erythrocytes of all species studied were seen to approach a spherical shape as the ph was increased above 7.5 and to become crenated at ph values below 7.3. The transition to a spherical shape in alkaline media is not due to an increase in volume but rather to a contraction of the surface membrane. It is suggested that the dog erythrocyte differs from that of other species in that its membrane can withstand less tension.
Acetate Metabolism: Effect of the Route of Tracer Dosage
Authors: Williams Wallace R. , Van Bruggen J. T.
Published: December 2017

Specially prepared adult rats were given tracer amounts of acetate-1-C14 intravenously or intraperitoneally. C14 incorporation into CO2 was followed on a time course basis and incorporation of the label into the fatty acid and cholesterol fractions of liver, gut, carcass and skin was determined. The dosage route was shown to affect the subsequent distribution of the label in the tissue lipids. Direct utilization of the acetate-1-C14 by tissues of the peritoneal space is considered to explain the high radioactivity of such tissues after i.p. dosage.
Effect of Diets Low in Organic Sulfur on Metabolism of Cholesterol-C14 in the Rat
Authors: Portman Oscar W
Published: December 2017

Mechanisms involved in the hypercholesteremia of rats fed diets relatively deficient in organic sulfur were investigated. Acetate-C14 was injected into rats fed diets including alpha-protein and into methionine-supplemented rats. The rates of synthesis and elimination of cholesterol-C14 from tissues were studied. The biological half lives of cholesterol-C14 in all tissues were similar for both diet groups. The rate of incorporation of acetate into cholesterol was somewhat less in the livers of rats from the deficient group at 40 minutes after injection of the acetate. The ratio of cholesterol to fatty acid synthesis was similar for the two groups. The mean acetylation of a test dose of p-aminobenzoic acid was almost identical for the two groups.
Effects of Intravenous Infusion of Autonomic Agents on Peripheral Blood 17-Hydroxycorticosteroid Levels in the Dog
Authors: Harwood C. Theresa , Mason John W.
Published: December 2017

The effects of autonomic agents on anterior pituitary-adrenal cortical axis in dogs were studied. 17-hydroxycorticosteroids (17-OH-CS), determined by Nelson-Samuels method, and eosinophils, by Randolph procedure, were measured in normal animals and following saline, ACTH, l-epinephrine, l-norepinephrine and physostigmine. Concentrations of 17-OH-CS three to four times the initial plasma levels were achieved by ACTH (0.4–4.0 mg/kg). Epinephrine (0.12 mg/kg) caused approximately twofold increases. Norepinephrine (0.017 mg/kg) and physostigmine (0.05 mg/kg) had no effect on 17-OH-CS concentration. Marked eosinopenia resulted from ACTH, epinephrine and physostigmine.
Direct Measurement of Changes in Cardiac Contractile Force
Authors: Cotten Marion deV. , Bay Edmund
Published: December 2017

Direct measurements of changes in the force of ventricular contraction with the strain gauge arch represent a sample of changes in the force of contraction of the entire ventricular muscle under conditions of an intact circulation. The responses of any given area of the ventricular muscle to repeated injections of the same dose of a cardiac stimulant drug are consistently similar. Further, there is a linear relationship between changes in the force of contraction as measured with the strain gauge arch and changes in the duration of the isometric pressure gradient. A direct relationship also exists between changes in contractile force and changes in stroke work. The relative advantages and limitations of the strain gauge arch and of the heart lever system, equipped with a strain gauge coil, are discussed in detail. Evidence is presented to show that the strain gauge arch is most useful in experiments in which substantial changes in the size of the heart do not occur. The heart lever system should be employed in experiments in which the size of the heart does undergo substantial change since adjustment may be made for changes in the initial diastolic fiber length. The time relations existing between direct recordings of contractile force made with the strain gauge arch and recordings of intravascular pressures have been demonstrated. A substantial portion of the contractile force is developed during the isometric phase of systole. There is a direct relationship between the amount of left ventricular contractile force developed during the isometric phase of contraction and the aortic diastolic pressure. A similar direct relationship exists between the total amount of contractile force measured by an arch on the left ventricle and the aortic systolic pressure. Mechanical stretching of the segment of muscle between the two points of attachment of the strain gauge arch produced length-tension curves which showed that a marked increase in contractile force occurs with increases in length of up to 40–60%. Stretching beyond these limits results in a progressive decrease in contractile force. The depth to which the sutures used in the attachment of the arch to the heart penetrated the myocardium has a moderate, but limited, quantitative influence upon the magnitude of contractile force measured. An arch attached with sutures penetrating deeply into the muscle measures more contractile force than an arch attached to the heart by superficially placed sutures.
Cerebral Impedance Changes After Circulatory Arrest
Authors: van Harreveld A. , Ochs Sidney
Published: December 2017

Cerebral impedance in the rabbit was measured between two electrodes placed on the dorso-lateral aspect of a hemisphere. The real part (resistance) was by far the larger component of the impedance. The effect of circulatory arrest on the reciprocal of the resistance (conductance) was examined. After cutting the aorta the brain conductance decreases, first slowly for 1–5 minutes. Then there is a sudden large drop in conductivity which is closely correlated in time with the development of a cortical negativity (asphyxial potential). After the rapid drop, the conductivity continues to decrease at a diminishing rate until after 4–5 hours the conductivity is only 20–30% of the value before circulatory arrest. The following factors were found to contribute to the drop in conductivity. Cooling of the brain to room temperature (25°C) causes a decrease of about 20%. Draining of fluid from the cortical surface and lateral sinus and perhaps draining of intercellular fluid accounted for a drop of 15–20% of the original conductivity. The emptying of blood vessels was estimated to cause a decrease of the order of 10%. Including its onset and decline the rapid conductance drop may cause a decrease of 30–35% of the original conductivity. It was postulated that the rapid conductivity drop is due to a transport of ions from the intercellular compartment into the cells and fibers of the brain tissue caused by a sudden increase in membrane permeability which also would cause the asphyxial potential.
Alterations in Electrolyte Intake and Adrenal Steroid Secretion
Authors: Rosnagle Robert S. , Farrell Gordon L.
Published: December 2017

Severe limitation of sodium intake in the dog leads to an approximate twofold increase in adrenal secretory rate of aldosterone, as determined by isolation of the steroid from adrenal venous blood. The rate of secretion of hydrocortisone remains unchanged. The administration of large amounts of potassium appears to be ineffective in altering adrenal secretion of aldosterone or of hydrocortisone. It is postulated that the increased urinary aldosterone associated with increased potassium intake described by others may be due to altered renal handling of the steroid.
Effect of Vitamin D and Ca:P Ratios on Chick Gastrointestinal Tract
Authors: Gershoff Stanley N. , Hegsted D. Mark
Published: December 2017

The effect of feeding diets containing various Ca:P ratios (4:1, 1:1, 1:2) to rachitic and nonrachitic chicks has been studied. The Ca:P ratios used had no significant effect on Ca absorption in chicks receiving vitamin D but were of importance in the Ca absorption of rachitic chicks. Vitamin D was found to increase Ca absorption in chick duodenum but had no effect on glucose absorption. Increased peristalsis was obtained when vitamin D or the least rachitogenic Ca:P ratio (1:1) was fed. A possible increase in intestinal mucosa respiration was also observed when vitamin D or the 1:1 Ca:P ratio was fed.
Relationship Between Protein Nitrogen, Proteolytic, Amylolytic and Lipolytic Enzymes in Canine Pancreatic Juice Obtained Under Various Conditions of Stimulation
Authors: Guth Paul H. , Komarov S. A. , Shay Harry , Style C. Zislin
Published: December 2017

Pancreatic secretion obtained from a dog with a permanent pancreatic fistula in response to each of four different kinds of test meals was analyzed for proteolytic, amylolytic and lipolytic activity with the view of studying possible correlation between the concentrations of the enzymes and protein nitrogen, and also possible effect of variation in composition of the test meals on these constituents. The enzyme activities were determined by phototurbidimetric methods, some of which were developed in this laboratory. Statistically significant deviations from proportionality between each of the enzymes and protein nitrogen, and also from the secretion of the enzymes in parallel concentrations occurred in specimens secreted in response to the same kind of test meal with day-to-day variation being the main contributing factor. With the exception of the relationship between amylase and protein nitrogen, deviations from enzyme-protein nitrogen proportionality and from the parallel secretion of the enzymes in specimens secreted in response to different test meals were not significantly greater than the daily variations which occurred in response to the same type of test meal. All these variations did not conform with any of the following widely held theories: a) proportionality between each of the enzymes and protein nitrogen, b) secretion of all enzymes in parallel concentrations regardless of composition of the test meal, and lastly c) purposive adaptation of concentrations of individual enzymes to the kind of food ingested. No evidence elucidating the physiologic mechanism of the variations observed was obtained.
Influence of Ouabain, Strophanthidin and Dihydrostrophanthidin on Sodium and Potassium Transport in Frog Sartorii
Authors: Johnson John A.
Published: December 2017

Ouabain and strophanthidin at a concentration of about 10–6 molar appear to inhibit the net transport of sodium out of and of potassium into the cells of the frog sartorius muscle under conditions where transport would otherwise occur. This inhibition occurs without significant effect on the resting potential. Dihydrostrophanthidin, also at a concentration of 10–6 m, failed to show the inhibitory action displayed by ouabain and strophanthidin.
Reserpine Suppression of Density-Dependent Adrenal Hypertrophy and Reproductive Hypoendocrinism in Populations of Male Mice
Authors: Christian John J.
Published: December 2017

The adrenal glands increase and the thymus and secondary reproductive organs decrease in weight when mice are placed in groups. These changes in weight are related to the size of the population or group and presumably are a reaction to sociopsychological pressures. If such a presumption is correct, reserpine should diminish the differences in the organ weights of grouped and of isolated mice. Grouped and isolated male mice were given 40–50 µg of reserpine (Serpasil, Ciba) per day in their drinking water and the results compared with those from similar numbers of grouped and isolated mice without reserpine. The average number of fights per 10-minute interval per day was 51.4% less in the treated than in the untreated mice for the first 3 days after grouping. Grouped mice, treated and untreated, had heavier adrenals and lighter thymus glands and secondary reproductive organs than their isolated controls. Treatment of grouped mice with reserpine was accompanied by a 5% lower adrenal weight, 28% greater thymus weight, and 12% greater seminal vesicle weight than were found in the untreated grouped mice. Reserpine treatment resulted in apparently comparable changes in the weights of these organs in isolated mice, but the differences were neither as great nor were they significant with the exception of the thymus gland. It was concluded that a) male mice responded to grouping with increases in adrenal weight and decreases in the weights of their thymus glands and secondary reproductive organs whether or not they had received reserpine; b) the response to grouping was not as great in the animals which had received reserpine; c) treatment with reserpine alone effects a reduction of adrenal weight and increases in the weights of the thymus and secondary reproductive organs; and d) reserpine reduces aggressiveness as measured by the number of fights between mice in groups.
Apparent Synthesis of Submaxillary Gland Amylase During Pilocarpine Administration
Authors: Schneyer Leon H. , Schneyer Charlotte A.
Published: December 2017

Administration of the parasympathomimetic drug pilocarpine has generally been observed to result in an increased rate of salivary secretion accompanied by depletion of gland stores of specific secretory proteins. In the experiments reported here, the expected increase in secretory rate and depletion of amylase stores were observed for the parotid glands of the rat after subcutaneous administration of pilocarpine. In the case of the sub-maxillary glands, short-term stimulation by pilocarpine, although observed to result in the expected increase in the rate of fluid secretion, led to no detectable depletion but to a rapid and appreciable increase in gland levels of amylase activity. Although the mechanism of this effect remains to be established, it appears possible that in this system stimulation by the parasympathomimetic agent pilocarpine results in an unmasking of a direct effect of stimulation on the process of synthesis of new enzyme.
Muscle and Liver Glycogen of Mouse Strains Susceptible or Resistant to Nutritionally Induced Obesity
Authors: Lyon John B. , Fenton Paul F.
Published: December 2017

Muscle and liver glycogen levels of mice differing in their susceptibility to nutritionally induced obesity were studied in relation to inherited differences in metabolic and endocrine patterns. The I/Fn strain, resistant to nutritional obesity, is characterized by a muscle glycogen level four to six times higher than those of strains which can be made obese. The liver glycogen of the I strain mouse is significantly lower than those of the other strains. Muscle glycogen levels were found to reach a maximum at about 6 months of age in all but one of our strains.
Mechanisms of Desoxycorticosterone Action. XI. Influence of the Pituitary
Authors: Girerd R. J. , Salgado E. , Green D. M.
Published: December 2017

The effects of a combination of DCA implantation and lyophilized whole pituitary (LWP) on the blood pressure, fluid exchange, growth, survival and tissue structure of hypophysectomized rats were compared with the effects of DCA and LWP alone, and of DCA in intact animals. The combination of DCA and LWP in hypophysectomized animals was followed by the development of hypertension and by the cardiac and renal hypertrophy associated with DCA hypertension in the nonhypophysectomized animal. These changes were milder in degree and were accompanied by little or no histological evidence of damage. The DCA-treated hypophysectomized animals which did not receive LWP developed neither hypertension nor cardiac and renal hypertrophy, although they did exhibit the increase in fluid exchange produced by DCA in intact animals. The results confirm the hypothesis that a factor or combination of factors present in the intact gland or in whole pituitary extract, but not present in single fractions previously tested, is an essential co-factor in the production of hypertension by DCA.
Effect of Cold Acclimation on Vascularization of Ears, Heart, Liver and Muscles of White Rats
Authors: Heroux O. , St. Pierre J.
Published: December 2017

The degree of vascularization of different tissues of rats killed with ether after a 4-week acclimation period to 30°C or 6°C was estimated by counting on benzidine stained cross-sections, capillaries in heart and leg muscles (soleus, gastrocnemius, plantaris), sinusoids in liver and all blood vessels in ears. Short exposure to cold (2 hr.) of the 30°C acclimated rats had no effect on the vascularization of any of the organs studied. Cold acclimation had no effect on number of capillaries in the heart and sinusoids in the liver, but in the ears it produced a 12-fold increase in number of blood vessels. In the plantaris and the red fiber regions of the gastrocnemius but not in the white fiber region of the latter, there was an absolute increase in the number of capillaries/mm2. In the soleus and the two heads of gastrocnemius, there were densely vascularized subregions which were on the average approximately 50% larger after cold acclimation. The increases in the number of opened capillaries observed in the ears and the leg muscles are interpreted as indicating a higher metabolism, and possibly an increased chemical thermogenesis in the red fiber muscles.
High-Energy Phosphate Content of Liver Tissue in Experimental Hemorrhagic Shock
Authors: Rosenbaum Dorothy K. , Frank Edward D. , Rutenburg Alexander M. , Frank Howard A.
Published: December 2017

The ‘high-energy phosphate’ content of liver tissue declines during the course of hemorrhagic shock in the dog. The degree of decline does not correlate with the loss of responsiveness to transfusion therapy. Phosphate energy stores depleted during hemorrhagic shock are rapidly rebuilt following replacement transfusion. Prior treatment with aureomycin reduces the depletion of phosphate energy stores during hemorrhagic shock. Aureomycin given in the same manner has been found to preserve the dog's responsiveness to transfusion therapy. The protective action of aureomycin in hemorrhagic shock is not attributable to the preservation of phosphate energy stores, however, because the change in these stores does not correlate with responsiveness to blood replacement.
Effect of Fasting on Muscle Proteins and Fat in Young Rats of Different Ages
Authors: Hagan Susie N. , Scow Robert O.
Published: December 2017

Rats 30–70 days of age were fasted for 3 or more days and changes in the amounts of various protein fractions and fat were measured in the thigh muscle. Only two protein fractions in the muscle, myosin and ‘water-soluble’ (sarcoplasmic) proteins, were decreased; the stroma and nonprotein nitrogen fractions were unchanged. It was found that only 20–27% of the calories that came from the thigh muscle were derived from protein and the rest, from fat. These findings are in agreement with many other reports that during fasting body proteins contribute only a small proportion of the calories that are needed for survival. There was no evidence of edema or ‘water-logging’ in the muscle of these fasting animals.
Effects of X-Irradiation on Renal Function of Rats
Authors: Smith L. H. , Boss W. R.
Published: December 2017

In a study of the direct effects of irradiation on the renal function of rats whose exteriorized kidneys were exposed to massive doses of x-rays, significant augmentation of the urine flow was observed 28 days after 2500 r. On the 7th day after 2500, 3000 and 4000 r the urine flow was slightly above that of control rats. The glomerular filtration rate was enhanced on the 7th day after 2500 and 3000 r. Conversely, 28 days after these x-ray doses the filtration rate was slightly below the control values. In the 4000-r, 28-day group, the glomerular filtration rate was 43% below that of the controls. No significant changes in the renal plasma flow occurred on the 7th day after 2500, 3000 and 4000 r. An insignificant increase in the renal plasma flow was noted 28 days after 2500 and 3000 r. On the 28th day after 4000 r, however, the renal plasma flow was 51% below that of the controls. We concluded that both augmentation and depression of renal function were the result of the direct action of x-rays on the kidneys. The results also suggest that renal failure resulting from direct irradiation damage to the kidneys is not a major factor that contributes to deaths occurring within 7 days after the exposure of rats to 4000 r or less of whole-body x-rays.
Mechanism of the Immediate Capillary Stress Response
Authors: Kramár Jenö , Meyers William V. , McCarthy Harry H. , Dietz Nicholas , Simay-Kramár Margarete , Williams James W.
Published: December 2017

Two possibilities may be considered for the mechanism of the immediate capillary stress response: the direct nervous origin, and the humoral. The latter was investigated in this study. Immediate capillary stress response was found in the absence of the adrenal, pituitary or thyroid glands, and after removal of both the adrenals and the pituitary. Among the 10 physiologic substances considered as playing a potential role in this phenomenon, three were found to possess capillary activity. Vasopressin as well as oxytocin increases capillary resistance. Histamine gives rise to a biphasic response, involving a decrease of capillary resistance (primary effect) followed by an increase (due to vasopressin elicited by histamine). By means of these substances it is possible to duplicate the immediate capillary stress response. During the immediate capillary response plasma has antidiuretic and chloruretic properties—a finding compatible with an increased vasopressin concentration and with the assumption that vasopressin is discharged rather regularly in the first phase of the stress response. The immediate capillary stress response seems to be the result of an interplay between vasopressin-oxytocin, and histamine. Species and individual differences in the sensitivity to these substances may account for the various patterns of the capillary response. The possible significance of the immediate capillary response and of the increased vasopressin activity in some clinical conditions is discussed.
Cardiovascular Reactivity After Hepatectomy
Authors: Page Irvine H. , Salmoiraghi G. C. , McCubbin J. W.
Published: December 2017

Removal of the dog's liver only slightly reduced pressor-depressor responses to test drugs during several hours after operation in the majority of experiments. The perfused vascular bed of one hind leg of these preparations also showed relatively normal responsiveness to drug and reflex stimuli. Other experiments contrasted with these in that responses to test agents were greatly reduced, or lost, in company with enhanced response to the depressor action of TEAC and predominantly depressor response to serotonin which is characteristic when neurogenic vasoconstriction is increased, as after severe hemorrhage, but hemorrhage was probably not alone accountable for the unresponsive state following hepatectomy, nor could a number of other factors be proved causative. Removal of an organ so importantly concerned with detoxication failed to augment responses to vasoactive agents.
Effect of Triton on Lipoprotein Lipase of Rat Plasma
Authors: Schotz Michael C. , Scanu A. , Page Irvine H.
Published: December 2017

When postheparin plasma was incubated with a coconut oil substrate, a decrease in optical density and an increase in unesterified fatty acids occurred. The increase in unesterified acids was prevented by previous intravenous injection of Triton to rats. Addition of post-Triton plasma to a system containing postheparin plasma and coconut oil emulsion inhibited the lipoprotein lipase activity. Incubation of Triton with coconut oil substrate before addition of postheparin plasma caused inhibition of lipoprotein lipase activity. It is concluded that inhibition of lipoprotein lipase activity by Triton is due to modification of the substrate such that the enzyme can no longer act. Further, it is suggested that the chief cause of Triton hyperlipemia is coating of the plasma lipoproteins by Triton resulting in their faulty catabolism.
Lobar Distribution of Pulmonary Circulation in the Supine and Erect Rat
Authors: Farhi Leon E.
Published: December 2017

When the bronchial tree is blocked, gas trapped in the alveoli is resorbed by blood which continues to flow through the lungs until death of the animal. The speed of gas resportion is proportional to the amount of blood flowing through the area. When the proper gas mixture is inspired, survival time is sufficient to cause atelectasis in some parts of the lung. These are obviously the better perfused parts relative to volume. In supine rats atelectasis was encountered in the right upper lobe more often than in the right lower lobe and the difference is statistically significant ( P < .001). In the erect position, the same results were obtained. This shows that the upper lobe is better perfused than the lower, regardless of posture. Discrepancy between work on man and dog—which indicate shifts in perfusion to the dependant parts of the lung on assumption of erect posture—and the present study is attributed to the small size of rats, in which changes in hydrostatic pressure differences between upper and lower lobes is necessarily small.
Relation of Dietary Fat to the Absorption and Elimination of Exogenous and Endogenous Cholesterol
Authors: Lin Tsung-Min , Karvinen Esko , Ivy A. C.
Published: December 2017

Page 89: Tsung-Min Lin, Esko Karvinen and A. C. Ivy, "Relation of Dietary Fat to the Absorption and Elimination of Exogenous and Endogenous Cholesterol." Table 3, column 3: 192 ± 8 should read 120.6 ± 8. Table 4, column 5, line 4: 46.5 should read 49.4; line 5: 18.0 should read 53.0. The text must be changed accordingly by the reader, since trielaidin ranks with triolein in regard to the facilitation of the absorption of cholesterol.
Osmotic Regulation of Body Fluids
Authors: Zuidema George D. , Clarke Neville P. , Minton Mary F.
Published: December 2017

Page 86: George D. Zuidema, Neville P. Clarke and Mary F. Minton, "Osmotic Regulation of Body Fluids." Lines 2 and 3, column 2: 2400, 3620, 2950 and 3750 Pitressin units should read 2400 µ, 3620 µ, 2950 µ and 3750 µ Pitressin units.
Cholesterol-Ascorbic Acid Relationship; Changes in Plasma and Cell Ascorbic Acid and Plasma Cholesterol Following Administration of Ascorbic Acid and Cholesterol
Authors: Booker Walter M. , DaCosta Frances , Jones William , Froix Cleo , Robinson Elise
Published: December 2017

Cholesterol when administered chronically in large amounts depressed the blood ascorbic acid content of cells or plasmas, or both, in rabbits and guinea pigs. Ascorbic acid administered simultaneously with cholesterol seemed to reduce the effect of the cholesterol. Acutely, ascorbic acid administration caused hypercholesterolemia in rats (noted also in other laboratory animals and in humans). It is suggested that hypercholesterolemia following ascorbic acid administration may result from liver release of cholesterol, which may be related to adrenal hormone action.
Reversal of Desoxycorticosterone Inhibition of Heart Beat by Serum Fractions
Authors: Cornman Ivor , Macdonald Mary , Trams Eberhard
Published: December 2017

The factor in serum that modifies the cardiac-inhibitory effects of DOC appears to be associated with a protein molecule having a molecular weight of 60,000–70,000. Heating the albumin fraction destroys its activity. Dialysis of serum indicates that one or more dialyzable cofactors are required for full activity of the serum. Of a number of compounds tested for their ability to antagonize DOC, l-cysteine is the most effective while glutathione and dl-homocysteine show slight activity. A study of a number of steroids related to DOC and progesterone revealed that the 21-hydroxy configuration is necessary for cardiac stimulation while progressive reduction at C-11 increases the cardiac inhibiting property of the steroid.
In Vivo Observations on the Seminal Vesicles of Adult Neonatally Castrated Rats Before and After Intravenous Testosterone
Authors: Knisely William H. , Grunt Jerome A. , Berry Roger J.
Published: December 2017

In vivo microscopic observations were made on the seminal vesicles of 12 neonatally castrated rats. After 30 minutes of study, during which the degree of vascularity and the visible linear rates of blood flow were noted, and the duration and frequency of contractions had been timed and recorded, an intravenous injection was made. The eight experimental animals received 300µg water-soluble testosterone (17-B diethylaminoethyl-carbonate hydrochloride) in 0.15 cc normal saline and the controls received 0.15 cc normal saline alone. No alterations were seen in the seminal vesicles of the controls following the injection except a decrease in the average total contraction time. At varying intervals following the injection of testosterone, there was an increase in the diameters of some of the small blood vessels, a concomitant increase in the visible linear rates of blood flow in these vessels, and a marked reduction in the frequency, duration and apparent strength of the contractions of the vesicles.
Effect of Prolonged Cold Exposure on Hepatic Lipogenesis
Authors: Masoro E. J. , Felts J. M. , Panagos Sylvia S.
Published: December 2017

Liver slices were prepared from ‘control’ rats kept at 25°C and from rats exposed to 0–2°C for 4–5 months. The ability of the tissue to convert acetate-1-C14 to C14O2 and fatty acid-C14 was determined. Slices from the cold-exposed rats incorporated much less acetate-1-C14 into fatty acids than did the livers from ‘control’ rats. This depression in lipogenesis existed even though the carbohydrate content of the livers of cold-exposed rats was identical to that of livers from ‘control’ rats. Carbohydrate metabolism of the liver slices was also studied and no differences were found between those from ‘control’ and cold-exposed rats. It is apparent that the depressed hepatic lipogenesis of rats exposed to cold for prolonged periods of time is not associated with a reduced ability of the liver slices to metabolize carbohydrate.
Combination of Insulin With Frog Skeletal Muscle
Authors: Gourley D. R. H.
Published: December 2017

Isolated intact frog skeletal muscles, equilibrated for a brief period of time in a solution of insulin and then rinsed thoroughly, showed an increased consumption of oxygen and an increased potassium uptake compared to controls when incubated for 6 hours without insulin. This has been interpreted as a firm binding of insulin to special reactive sites at the muscle cell surfaces. An equilibration period of 1 minute and an insulin concentration of 0.5 U/ml were sufficient conditions for saturating all of the sites concerned with oxygen consumption but not for all of those concerned with potassium transfer. In addition an aged insulin solution lost its ability to stimulate potassium uptake before the effect on oxygen consumption was altered. It is therefore concluded that there is one type of reactive site concerned with oxygen consumption with which insulin combines rapidly and another type of reactive site concerned with potassium transfer with which insulin combines relatively more slowly.
Effect of Bilateral Cervical Vagotomy in the Dog
Authors: MacCanon D. M. , Horvath Steven M.
Published: December 2017

Dogs subjected to bilateral cervical vagotomy were maintained by daily infusions of physiological saline and glucose for several weeks and a few animals survived for periods of more than 1 month. The success of this procedure is interpreted as evidence of water and electrolyte changes being major factors in the usual early demise of vagotimized animals. Cardiac outputs were decreased progressively after vagotomy resultant to increased arterial venous oxygen differences. Only slight additional alterations in the hemodynamic picture were noted as these animals survived the acute reactions to cervical vagotomy.
Venous Return at Various Right Atrial Pressures and the Normal Venous Return Curve
Authors: Guyton Arthur C. , Lindsey Arthur W. , Abernathy Berry , Richardson Travis
Published: December 2017

The normal venous return curve has been determined in 12 open-chest dogs with intact circulatory reflexes and in 14 open-chest areflex dogs. These curves show that venous return reaches a maximum value when the right atrial pressure falls to –2 to –4 mm Hg and remains at this maximum value down to infinitely low negative pressures. As the right atrial pressure rises to positive values venous return falls and reaches zero when the right atrial pressure has risen to equal the mean circulatory pressure. A venous return curve for the normal, intact dog has been tentatively formulated on the basis of these studies and previous studies in which individual points on the venous return curves of intact dogs have been measured.
Direct Effects of Adrenal Cortical Steroids on the Electrolyte Content of Rabbit Leucocytes
Authors: Wilson D. Laurence
Published: December 2017

Viable rabbit leucocytes have been obtained in quantities sufficient to permit direct chemical analyses of intracellular sodium and potassium concentrations. Treatment in vitro either with cortisone (10 or 20 mg/l.) or with desoxycorticosterone glycoside (10–80 mg/l.) led to a fall in intracellular potassium concentration and a reciprocal rise in intracellular sodium. There was an associated rise in intracellular water. After cortisone, the absolute change in sodium concentration slightly exceeded the reciprocal change in potassium; after desoxycorticosterone glycoside, the reverse was true.
Systemic and Coronary Pressure-Flow Relationships During Total Body Perfusion in the Dog
Authors: Read Raymond C. , Johnson John A. , Kuida Hiroshi
Published: December 2017

Fifty dogs have been perfused at flow rates of between 5 and 100 cc/kg/min. with complete cardio-pulmonary bypass for up to three hours using a pump-oxygenator. There was an approximately linear relationship between pressure and flow. Extrapolation to zero flow produced an intercept on the pressure axis of approximately 20 mm Hg. Calculated total systemic resistance was more uniformly related to flow than to pressure. Coronary blood flow did not correlate with perfusion pressure. There was, however, an inverse relationship between perfusion rate and the percentage of total flow passing through the coronary bed. Coronary resistance decreased with perfusion time whereas total systemic resistance rose initially and then declined. Total peripheral resistance in these open chest perfused animals was one to two times the accepted normal for the intact dog. The actual value varied with the anesthetic agent used.
Effects of Hypophysectomy on Daily Temperature Variation in C3H Mice
Authors: Ferguson D. J. , Visscher M. B. , Halberg F. , Levy L. M.
Published: December 2017

Body temperatures were measured with a thermistor inserted through the rectum in intact and hypophysectomized male C3H mice, kept under standardized conditions of environmental temperature and lighting. At 1 month after hypophysectomy, temperature measurements were made on all the mice at 4-hour intervals during a 4-day period. At about 5 months after operation, measurements were made once, on separate subgroups of mice, at a 12-hour interval; this experiment was repeated 3 days later. At 1 month after hypophysectomy, the mean temperature was lower, the amplitude of daily change was smaller, and the period was slightly shorter, compared to intact controls, but there remained a significant difference between night and day mean temperatures. At about 5 months after operation, daily variations in the group mean were no longer of significant amplitude at the two times when they were measured, compared to those in intact mice.
Effect of Intraperitoneal Serum Albumin on the Excretion and Renal Localization of Mercury After Mercuric Chloride Injection in Rats
Authors: Surtshin A. , Parelman Allen G.
Published: December 2017

Normal rats pretreated with intraperitoneal bovine serum albumin have been compared with saline-injected controls with respect to the amounts of mercury present in the kidneys and in the collected urine 24 hours after the intravenous injection of radiomercuric chloride. The albumin-injected rats excreted significantly smaller amounts and their kidneys contained significantly greater amounts. The reduction in renal toxicity of mercuric chloride, previously described by others to be associated with serum albumin administration, is not due to an increase in the excretion of mercury as a result of the induced proteinuria or to a decrease in the amount of mercury present in the kidney as revealed by analysis in 24 hours.
Proteolytic Activity of Guinea Pig Serum Activated by Streptokinase-Human Plasminogen Preparations
Authors: Meyers Wayne M. , Burdon Kenneth L.
Published: December 2017

The incubation of guinea pig serum with a streptokinase-human plasminogen preparation (from purified plasminogen) activates a proteolytic enzyme in the guinea pig serum. Optimal conditions for activity, kinetics, Km values and heat stability of elements of this system were studied. The proteolytic activity of this system was strongly inhibited by lysine ethyl ester and p-toluenesulfonylarginine methyl ester, apparently in a competitive manner. Serum dilution activity curves suggest the presence in guinea pig serum of dissociable protease inhibitors. The proteolytic activity of human plasmin does not appear to be essential for the activation of guinea pig protease, as indicated by heat stability studies. Possible mechanisms of activation are discussed. A survey of other animal species showed the widespread presence of serum proteases which could be activated with streptokinase-human plasminogen mixtures. The human activator systems may prove to be a useful tool in experimental studies of the physiological significance of the protease system.
Organization of Central Respiratory Mechanisms in the Brain Stem of the Cat: Localization by Stimulation and Destruction
Authors: Ngai S. H. , Wang S. C.
Published: December 2017

With electrical stimulation and circumscribed electrolytic destruction, the pneumotaxic center is localized in the dorsolateral reticular formation of the isthmus of the pons. Destruction of the pneumotaxic center and vagotomy result in apneustic respiration. The pneumotaxic center functions independently to modulate and facilitate the phasic activity of the lower respiratory centers. This function is analogous to that of the pulmonary vagal afferents. The apneustic center is probably localized in the lateral reticular formation of the middle pons and extends medially toward the caudal portion of the pons. The medullary inspiratory center is localized in the ventral reticular formation rostral to and at the level of the obex. Stimulation of these structures yields marked inspiratory spasm. Forced expiratory responses are obtained on stimulation of a circumscribed area in the dorsal portion of the medulla 1–3 mm caudal to the obex, which probably constitutes the expiratory center.
Anodal Excitation of Cardiac Muscle
Authors: Cranefield Paul F. , Hoffman Brian F. , Siebens Arthur A.
Published: December 2017

The strength-interval curve of dog ventricular myocardium has been measured with anodal and cathodal stimulation. During diastole the anodal threshold is higher than the cathodal. As anodal stimuli are applied progressively earlier the anodal threshold first rises above and then falls to levels below the anodal diastolic threshold. During most of the relative refractory period the anodal threshold is lower than the cathodal threshold. At all times during the late relative refractory period and throughout diastole excitation of double origin (anodal and cathodal) is evoked by sufficiently strong stimuli; this simultaneous origin of excitation at two points does not evoke fibrillation. During the early relative refractory period, however, only the anode is able to excite. Differences between anodal and cathodal thresholds are not attributable to asynchronous repolarization at the two electrode sites. The ‘no-response’ phenomenon occurs only when the anodal threshold is markedly lower than the cathodal.
Effect of Hypoxia on Serum Iron and the Unsaturated Iron-Binding Capacity of Serum in Rats
Authors: Colehour J. K. , Borsook Henry , Graybiel Ashton
Published: December 2017

In rats exposed to acute hypoxia there was immediate increase in unbound iron binding capacity (mainly siderophilin or transferrin) and fall in serum iron before the mor phology of the circulating blood was altered.