bluuebunny/crossref_metadata_2025_split huggingface dataset:
Distribution of maximum coronary blood flow in the left ventricular wall of anesthetized dogs
Authors: Bagger Henning 
Published: December 2008

AbstractBlood flow in the circumflex branch of the left coronary artery was recorded by electromagnetic flowmeter. In a group of dogs progressive hemodilution was performed until the diastolic reactive hyperemic response to 10 s occlusion of the circumflex branch disappeared (“optimum” hemodilution). At this degree of hemodilution the distribution of blood flow in the left ventricular free wall was evaluated by measuring tissue activity concentrations of Xe‐133 and radioactive microspheres after bolus injection into the aortic root. “Optimum” hernodilution was accompanied by a sixfold increase in systolic coronary flow, a 3‐fold increase in diastolic flow and a relative endocardial hypoperfusion. These results indicate that the endocardial blood flow reserve is lower than the epicardial. This conclusion is supported by the influence of spontaneous oscillations of arterial blood pressure (Traube‐Hering waves) on systolic and diastolic coronary blood flows before and during “optimum” hemodilution. In another group of dogs maximum coronary vasodilatation was produced by occlusion of the left coronary artery for 10 s. In this group the distribution of Xe‐133 and radioactive microspheres were measured after bolus injection into the aortic root at peak diastolic reactive hyperemia. The epi‐ and endocardial distribution of both Xe‐133 and microspheres was uniform in the left ventricular wall, indicating a uniform flow to these regions. This might be explained by an increased endocardial perfusion during systole due to loss of myocardial contractility or by a decline towards resting level in epicardial flow at the time of injection, corresponding to a shorter duration of the hyperemic period in the epi‐ than endocardial region.
Blood flow, calcium deposition and heat loss in reindeer antlers
Authors: Hove Knut , Steen Johan B. 
Published: December 2008

AbstractAntler blood flow was studied in a 2 year old male reindeer during the last half of the antler growth period using an electromagnetic flow probe chronically implanted around the superficial temporal artery. Arterio‐venous (a‐v) differences of calcium were measured on antler blood. The blood flow increased from 60–90 ml/min when the antler was half‐grown to 100–120 ml/min when fully developed. Subsequently a reduction was observed towards shedding. Positive a‐v plasma calcium differences (on average 0.2 mM) were recorded during the period of active growth. Two bulls maintained positive a‐v calcium differences after a 48 hour starvation period, in spite of reduced arterial calcium concentrations. Exercise to near exhaustion caused a 2°C rise in the rectal temperature. Antler blood flow was decreased immediately after exercise and returned to pre‐exercise values usually within 5–10 min. Since no overshoot in antler blood flow was recorded during the hyperthermia it is concluded that variations in blood perfusion of the antlers are without importance in the defence against hyperthermia during and after exercise.
Activity of acid hydrolases in skeletal muscle of untrained, trained and detrained mice of different ages
Authors: Pilström Lars , Vihko Veikko , ÅStröm Eva , Arstila Antti U. 
Published: December 2008

AbstractThe activities of p‐nitrophenylphosphatase, β‐glucuronidase and β‐N‐acetylglucosaminidase from crude skeletal muscle homogenates of 4 and 7 months old mice were assayed after short‐term intensive and long‐term moderate training and after terminated training. In the older untrained mice the activity of the hydrolases was higher than in the younger mice. The level increased with training and this increase was far more pronounced in the older animals. Cessation of training for 7 and 21 days decreased this activity in the older animals but it was again increased 42 days later and cIose to the level observed in the trained mice. In young mice 3 days' terminated training increased the activity of the acid hydrolases above the level of the trained animals but after additional 4 and 11 days' terminated training the activity decreased to slightly below that of the trained mice. The changes were most prominent in the activity of β‐glucuronidase and to a lesser extent in that of β‐N‐acetylglucosaminidase while p‐nitrophenylphosphatase activity was almost unaffected by training or terminated training. The effects of terminated training can he intepreted as representing altered catabolic processes in the turn‐over of tissue components of skeletal muscle.
Anticholeretic effect of somatostatin in anesthetized dogs
Authors: Holm Inger , Thulin Lars , Samnegård Hans , Efendic Suad , Tydén Gunnar 
Published: December 2008

Summary.Somatostatin, 0.2‐1.0 βg. kg‐l min‐1, was administered i.v. in 5 anesthetized dogs. Following 9‐min infusions, hepatic bile output was found to decrease by approximately 50% after a latency of 6 min. The mode of action suggests that somatostatin inhibits hormone‐induced bile output.
Insulin production by pancreatic islets of obese‐hyperglycemic mice cultured for one week in different glucose concentrations
Authors: Andersson Arne , Asplund Kjell , Larkins Richard 
Published: December 2008

AbstractAnderson, A., K. Asplund and R. Larkins, Insulin production by pancreuric islets of obese‐hyperglycemic mice cultured for one week in different glucose concentrations. Acta physiol. scand. 1978. 104. 377–385.Culture of pancreatic islets isolated from obese‐hyperglycemic mice (gene symbol oh) for one week in media containing widely different concentrations of glucose (3.3, 5.6 or 16.7 mM) was found to markedly influence the functional behaviour of the islet B‐cells. Thus, the insulin content of islets cultured at 3.3 or 16.7 mM glucose (subphysiological or supraphysiological glucoce concentrations respectively) was markedly reduced. Islets cultured in 5.6 or 16.7 mM glucose displayed a normal insulin secretory response when stimulated with glucose, whereas islets cultured in a subnormal glucose concentration (3.3 mM) showed a reduced insulin response to glucose stimulation in batch type incubations and also lacked a second phase of insulin secretion in islet perifusion experiments. The rate of insulin biosynthesis of non‐cultured ob/ob islets was higher than that of islets from Lheir lean siblings but cuiture for one week in 3.3 mM glucose induced a pronounced impairment of the insulin biosynthesis in islets of obese as well as lean mice. The present data indicate that the hyperfunction of the islets of the ob/ob mouse at least in part is a reversible phenomenon, suggesting that inherent properties of islet B‐cells do not act as “primary” factors in the development of the obese‐hyperglycemic syndrome.
Metabolic and cardiovascular responses to prolonged noradrenaline load and their antagonism by beta blockade in the rat
Authors: Harri By Mikko N. E. 
Published: December 2008

AbstractHarri, M. N. E. Metabolic and cardiovascular responses to prolonged noradrenaline load and their antagonism by beta blockade in the rat. Acta physiol. scand. 1978. 104. 402–414.Rats were given daily injections of noradrenaline (0.5 mg/kg), alprenolol (20 mg/kg), or both together for 17 to 39 days. Noradrenaline injections increased the size of the heart, interscapular brown adipose tissue (ISBAT) and, when the injections were given at a thermoneutral environment, the metabolic activity of the ISBAT. Alprenolol injections tended to reduce the size of the heart and ISBAT and, at a thermoneutral environment, metabolic activity of the skeletal muscle. Furthermore, noradrenaline treatment improved tolerance against body cooling in water at 25°C and enhanced calorigenic response to injected noradrenaline. The metabolic alterations in the rats injected with both drugs together resembled more those of the animals injected with alprenolol only than those of the noradrenaline treated rats. It can be thus concluded that alprenolol, when given together with noradrenaline, antagonized noradrenaline‐induced metabolic alterations in the organism. However, the increased pressor response to infused noradrenaline, which was evident in the alprenolol treated animals, was not seen in the animals treated with both drugs. By contrast, these animals, like also the noradrenaline‐treated animals, showed decreased pressor response to noradrenaline. This finding suggests that prolonged beta blockade does not abolish the decreased sensitivity of alpha‐adrenoreceptors following prolonged noradrenaline load. On the other hand, the hypotonic response to a beta adrenergic drug, isoprenaline, was reduced by prolonged beta blockade despite simultaneous noradrenaline injections.
Effect of synthetic substance P on internal carotid artery blood flow in man
Authors: Samnegård Hans , Thulin Lars , Tydén Gunnar , Johansson Claes , Muhrbeck Olle , Björklund Christer 
Published: December 2008

AbstractSamnegård, H., L. Thulin, G. Tydén, C. Johansson, O. Muhrbeck and C. Björklund, Effect of synthetic substance P on itzternul carotid artery blood flow in man. Acta physiol. scand. 1978. 104. 491–495.Internal carotid artery blood flow was studied by peroperative electromagnetic blood flow measurement in 7 patients following 9 intravenous infusions of synthetic Substance P, 2 ng·kg‐1.min‐1. The blood flow responses varied interindividually. No significant blood flow changes were observed for the whole group. The arterial mean blood pressure decreased significantly.
Effect of plasma H+‐ion concentration on pancreatic HCO‐3 secretion
Authors: RÆDER MORTEN , MO ARVE , AUNE SNORRE 
Published: December 2008

AbstractThe relationship between the rate of pancreatic HCO‐3 secretion and plasma H+‐ion concentration was investigated in 15 pentothal anesthetized, secretin infused pigs (1.8 C.U./kg b.w. h‐1 intravenously) during acute metabolic and respiratory acid‐base disturbances. Pancreatic HCO‐3 secretion increased to 196 ± 10% of control during alkalosis and fell to 41 ± 4% of control during acidosis. Partial metabolic compensation of respiratory acidosis restored HCO‐3 secretion to 87 ± 6% of control. A proportional relationship was found between HCO‐3 secretion and plasma pH. Different, proportional relationships were found between HCO‐3 secretion and plasma HCO‐3 concentration during metabolic and respiratory acid‐base changes. HCO‐3 secretion was independent of H+‐ion concentration in pancreatic juice. Plasma H+‐ion concentration, therefore, seems to determine the rate of pancreatic HCO‐3 secretion. This finding supports the hypothesis that a proton pump is responsible for pancreatic HCO‐3 secretion.
Effects of vasoactive intestinal polypeptide on blood flow, motility and fluid transport in the gastrointestinal tract of the cat
Authors: EKLUND STEFAN , JODAL MATS , LUNDGREN OVE , SJOQVIST ANDERS 
Published: December 2008

AbstractThe effect of close intraarterial infusions of vasoactive intestinal polypeptide (VIP) on gastric motility, intestinal fluid transport and colonic motility were studied in the cat. Regional blood flow was also followed in all experiments. In the stomach VIP produced a gastric relaxation and a blood flow increase. The motility response was similar to that observed when eliciting the vago‐vagal reflex relaxation by distending the esophagus. In the small intestine a hyperemia and a decrease of net water uptake was observed. When infusing small amounts of VIP a decrease of net water uptake was seen without any change of intestinal blood flow. Large amounts of VIP produced a transient secretory state in the small intestine. In the colon a hyperemia was seen immediately upon starting the infusion of the drug. After 2–3 min of infusion a contraction of the colon was apparent. The administration of atropine to the animal did not significantly affect any of the responses produced by VIP. The results are discussed in relation to VIP as a possible neurotransmitter in the gastrointestinal tract.
Prevention of protein extravasation in the brain by an anion transport inhibitor in acute experimental hypertension in rats
Authors: HANSSON HANS‐ARNE , JOHANSSON BARBRO B. 
Published: December 2008

AbstractAcute experimental hypertension induces protein leakage in the brain. The protein is thought to be, at least to a great extent, transported through the endothelial cells by pinocytosis. An anion transport inhibitor, 4 acetamido‐4‐isothiocyano‐stilbene‐2,2′‐disulfonic acid, markedly reduced adrenaline or bicuculline‐induced leakage of 125IHSA and Evans blue‐albumin in all areas of the rat brain. The preventive effect of dexamethasone was less pronounced and no effect was seen of haloperidol.
Possible role of thiamine in neuromuscular transmission
Authors: WALDENLIND LENNART 
Published: December 2008

AbstractPyrithiamine (50 mg/kg), a thiamine antagonist, decreased the muscle twitches of the rat masseter muscle at stimulation frequencies above 1 Hz 40–80 min after an i.v. injection. The post‐tetanic potentiation (PTP) induced by nerve stimulation of the masseter muscle was abolished by pyrithiamine. Administration of thiamine restored the muscle twitches at stimulation frequencies above 1 Hz and the PTP. The muscle twitches elicited by direct muscle stimulation were not affected by pyrithiamine treatment. The abolishment of the PTP was accompanied by a decrease in thiamine and thiamine‐diphosphate. The pyruvate level in the blood was unchanged after pyrithiamine treatment. Oxythiamine, on the other hand, had no effect on the PTP but increased the pyruvate level in the blood. Fern extract which contains thiaminase I also abolished the PTP–an effect reversible by the addition of thiamine. The frequency‐induced depression of the muscle twitches induced by pyrithiamine was similar to the effect of low doses of d‐tubocurarine (8 μg/kg). The results support the hypothesis that thiamine may play a role in neuromuscular transmission.
Ventilatory and occlusion pressure response to CO2 and hypoxia with resistive loads
Authors: BARNETT THOMAS B. , RASMUSSEN BIRGER 
Published: December 2008

AbstractSteady‐state responses to hyperoxic hypercapnia and eucapnic hypoxia were measured both as minute ventilation (VE) and as inspiratory mouth occlusion pressure (P0.1) with and without 25 cm H2O/l/s added resistance (R). Reduction in slope of the ventilatory response to CO2 with R was highly significant in all 3 subjects whereas the response to hypoxia was barely significantly reduced in 1 subject and not significantly decreased in two. Although P0.1 was higher with than without R under all conditions, the slope of the P0.1 response to CO2 with R was not increased in two subjects and only slightly increased in the third. The slope of the P0.1 response to hypoxia was significantly greater in all subjects with R. Expiratory reserve volume was increased with R but the change was the same with hypoxia and hypercapnia. We conclude that ventilation is better maintained with resistive loading during hypoxia than during hypercapnia and that this results from a greater force output of inspiratory muscles as reflected by a higher P0.1. This suggests a greater neural output to these muscles.
Differences in renal and submaxillary renin release after stimulation with isoprenaline and noradrenaline
Authors: BING JENS , POULSEN KNUD 
Published: December 2008

AbstractIt is confirmed that while noradrenaline stimulates release of submaxillary as well as renal renin, isoprenaline only stimulates renal renin release. The effects of these two adrenergic agonists differ in several other ways. The kidneys respond to isoprenaline with a dose dependant renin release. As a contrast the submaxillary glands respond to noradrenaline by no or by non‐dose‐dependant release. After single doses of the agonists the isoprenaline induced renin release is of short duration, contrasting with a prolonged renin release after injection of noradrenaline. The kidneys are able to respond to repeated doses of both agonists, while the submaxillary glands most often only respond to the first dose. While the effect of noradrenaline is blocked by pretreatment with phenoxybenzamine, this blocker is without effect when given after noradrenaline. The two agonists do not provoke any increase in plasma renin in mice which have been both sialoadenectomized and nephrectomized.
Capillary permeability measured by bolus injection, residue and venous detection
Authors: SEJRSEN PER 
Published: December 2008

AbstractKinetic analysis of residue and outflow curves of y‐emitting indicators such as chromium‐51‐EDTA and iodide‐131‐thalamate from skeletal muscle gives the possibility to determine the extraction fraction and the plasma flow, and from these two values the capillary diffusion capacity can be calculated (Sejrsen 1970, preliminary report). This is possible both for the transport from blood to tissue and from tissue to blood. This alternative method has been compared in the autoperfused cat gastrocnemius preparation with the indicator diffusion method based on venous registration of a diffusible test indicator and an intravascular reference indicator (Chinard et at. 1955, Crone 1963). The results of the five independent measurements show good agreement. Calculation of the permeability Pd based on a capillary surface area of 7 000 cm2/100 g of tissue gives values of 1.05–10‐5, 1.10–10‐5, and 1.16–10‐5 cm/s, which is in agreement with results obtained by other investigators. The permeability was equal in both directions, and thus the capillary membrane seems to function as a symmetrical membrane. Using an area of 5 000 cm2/100 g which presumably is more realistic at the plasma flow range used gives Pd values around 1.5–10‐6 cm/s. The effective pore area is calculated to constitute 1/50 000 of the capillary surface area. Calculation of volumes of distribution in the muscle tissue gave intravascular plasma volumes of 1.8 to 2.0 ml/100 g, an extravascular volume of 12.4 and 15.2 ml/100 g and a final monoexponential component constituting a compartment of 5.4 and 7.0 ml/100 g from residue and venous curves, respectively. The last mentioned compartment constitutes nearly 50 per cent of the extravascular space, and it is suggested, that it is located inside the sarcoplasmic reticulum, which anatomically constitutes about 50 per cent of the interstitial space. The total area of contact between the longitudinal and the transversal tubules in this subsystem, which is the membrane of the lateral saccus, is estimated to about 6 times the capillary surface area at a plasma flow of 15 ml/100 g min which gives a permeability about 60 times lower for this membrane compared to the capillary membrane.
A phenomenologic evaluation of CO2‐diffusion restriction in kidney tubules studied in an artificial membrane system
Authors: Sohtell Morgan 
Published: December 2008

AbstractThe chemical course in a multi‐membrane system with interacting H+ and HCO3 ions has been described phenomenologically as an analogy of the neutralisation reaction between secreted H+ and filtered HCO3 ions in the proximal tubules of the kidney. It was shown that the produced CO2 gave the highest PCO2 in the asymmetrically placed reaction centre, which favours a build‐up of a high intratubular PCO2. The CO2 transport was dependent on the rate‐limiting permeation of the reacting ions, and the permeation could be increased by the influence of solutions of macro molecules such as carbonic anhydrase, albumin and dextran.
Synaptosomal accumulation of intracerebral injected amino acids
Authors: Karppinen Anneli , Kumpulainen Elsa , Lähdesmäki P. 
Published: December 2008

AbstractThe distribution of the labels of [35S]taurine, [3H]lysine, [14C]glutamate and [11C]norleucine in mouse brain subcellular fractions was followed after intracerebral injection in vivo. [35S]taurine, [3H]lysine and [14C]gluta‐mate and its metabolites accumulated in the nerve terminals, lysine and glutamate also occurring in the synaptic vesicles, while taurine remained mainly in the soluble synaptoplasm. [14C]norleucine penetrated the brain cell membranes slowly, but was still bound to the synaptic vesicles to a greater extent than taurine.
Rapid increase of glycosaminoglycans in the aorta of hypercholesterolemia rats; a negative correlation with plasma HDL concentration
Authors: Tammi Markku , Rönnemaa Tapani , Vjikari Jorma 
Published: December 2008

AbstractRats were kept either on a standard laboratory diet or a high cholesterol, olive oil diet for periods ranging from 1 day to 22 weeks. The effect of the high cholesterol, olive oil diet on the concentrations of cholesterol, glycosaminoglycans (GAGs) and collagen in aortic intima‐media, were studied and the developing hyper‐lipidemia was characterized. The concentration of cholesterol in rat aorta was increased after 22 weeks' high cholesterol, olive oil diet, while collagen concentration was not affected. On the contrary, the concentration of aortic sulphated GAGs was significantly increased already after one week's high cholesterol, olive oil diet. The diet increased the formation of a cholesterol‐rich very low density lipoprotein (VLDL), decreased high density lipoprotein (HDL)‐associated cholesterol and phospholipids, but had virtually no effect on low density lipoprotein (LDL)‐lipids. The concentrations of VLDL‐cholesterol and ‐phospholipids showed positive correlations with the concentration of aortic GAGs (r = 0.89 and 0.83, respectively, P < 0.05 for both). Stronger (negative) correlations were found between aortic GAGs and HDL‐cholesterol and ‐phospholipids (r = ‐0.94 for both, P <0.01) suggesting that HDL may have a role in the control of arterial sulphated GAG concentration.
In vitro effects of growth hormone on protein synthesis and amino acid transport in the rat diaphragm after acute hypophysectomy
Authors: Albertsson‐Wikland Kerstin , Edén Staffan , Isaksson Olle 
Published: December 2008

AbstractThe effects of growth hormone (G H) in vitro on phenylalanine‐14C incorporation to assess protein synthesis and on a‐aminoisobutyric‐l‐3H accumulation to measure amino acid transport in the diaphragm muscle of the rat were investigated 2, 6 and 24 h after hypophysectomy or sham‐operation. In hypophysectomized animals protein synthesis was depressed. GH in vitro was without effect 2 h after hypophysectomy but stimulated protein synthesis 6 and 24 h after the operation. Six hours after hypophysectomy amino acid transport was enhanced and further stimulated by GH. After 24 h amino acid transport was depressed but was stimulated to normal levels by GH. Six hours after sham‐operation protein synthesis was depressed, but was stimulated by GH. After 24 h protein synthesis was normalized and GH was without effect. GH did not influence amino acid transport after sham‐operation. Plasma levels of GH were undetectable after hypophysectomy, markedly depressed 2 and 6 h after sham‐operation, but normal after 24 h. It is concluded that tissue responsiveness to GH develops a few hours after hypophysectomy.