摘要:

AbstractIn the absence of the antrum, central vagal excitation and distension of the stomach accelerated the rate of formation of gastric mucosal histamine. The effect of vagus stimulation was abolished by truncal vagotomy or atropine whereas that of distension by atropine. After truncal vagotomy, distension was still effective in accelerating the formation of the amine. Furthermore, mucosal histamine formation in the fasting state was reduced by truncal vagotomy and atropine injection.

ISSN:0001-6772    

DOI:10.1111/j.1748-1716.1976.tb10246.x

出版商:Blackwell Publishing Ltd    

年代:1976

数据来源: WILEY

摘要:

AbstractTotal lactate dehydrogenase (LDH) activity and LDH isozyme pattern were studied in muscle biopsies obtained from m. vastus lateralis after 1) “aerobic” training performed as interval and extreme distance running, respectively (3 subjects); and 2) “anaerobic” training for two months, carried out as repeated maximal bursts of approximately 1 min running (6 subjects). After the “anaerobic training” no changes in LDH properties could be detected, although running performance improved. The extreme distance running resulted in a decrease in total LDH activity and an increase in relative activity of the heart specific isozymes. A relationship was also shown between the relative activity of these isozymes and the training distance covered. The relatively more aerobic conditions prevailing during distance running as compared to “anaerobic training” were proposed to decrease muscle specific subunits and/or increase synthesis of heart specific subunits in both muscle fibre types. This suggestion was supported by isozyme analysis of lyophilized and dissected singl

ISSN:0001-6772    

DOI:10.1111/j.1748-1716.1976.tb10247.x

出版商:Blackwell Publishing Ltd    

年代:1976

数据来源: WILEY

摘要:

AbstractIn anesthetized dogs electrocardiogram and monophasic action potentials (MAPs) were recorded from the right atrium and the right ventricle by intracardiac suction electrode technique. The animals were subjected, by means of ventilation with CO2and hyperventilation, to periods of respiratory acidosis and respiratory alkalosis, respectively. Pronounced respiratory acidosis induced an increased sympathetic activity followed by a decrease in heart rate and prolongation of the A‐V conduction time whereas the shape and duration of the atrial and ventricular MAPs remained unaltered. Arterial hypoxia in combination with pronounced respiratory acidosis did not influence the MAP durations. Respiratory alkalosis resulted in an increased sympathetic influence on the heart activity whereas the shape and duration of the atrial and the ventricular MAPs remained unaffected. During pronounced hyperventilation with increasing central venous pressure an increased parasympathetic influence on the heart activity with decrease in the heart rate, prolongation of the A‐V conduction time and shortening of the atrial MAP duration was recor

ISSN:0001-6772    

DOI:10.1111/j.1748-1716.1976.tb10248.x

出版商:Blackwell Publishing Ltd    

年代:1976

数据来源: WILEY

摘要:

AbstractNet transvascular movement of fluid has been studied in the isolated, autoperfused subcutaneous adipose tissue of the dog, during and after sympathetic nerve stimulation (1–15 Hz) and during infusion of 50% glucose i.a. Net fluid movement was calculated as the difference between change in tissue volume and change in blood volume. Tissue volume was measured by plethysmography and blood volume by external monitoring of circulating131I‐albumin. No net fluid movement of statistical significance was found during or after nerve stimulation except during the first minute of stimulation at 15 Hz when a small net absorption (p<0.05) was obtained. In contrast, infusion of glucose at 25–75 mOsm/kg H2O produced a dose‐dependent net absorption lasting several minutes, amounting maximally to 0.30 ml × min‐1× 100 g‐1. The absence of prolonged net absorption in subcutaneous adipose tissue during nerve stimulation as well as the absence of net filtration after stimulation may be explained by an essentially unaltered mean hydrostatic capillary pressure. The results indicate that adipose tissue does not contribute to the fluid homeostasis of the body via sympathetic resetting of the pre‐postcapillary resistance ratio. Thus, mobilisation of fluid from the nterstitial space in adipose tissue into the blood does not seem to occur by

ISSN:0001-6772    

DOI:10.1111/j.1748-1716.1976.tb10249.x

出版商:Blackwell Publishing Ltd    

年代:1976

数据来源: WILEY

摘要:

AbstractThe time course of the excitability of the inspiratory ‘off‐switch’ mechanism with and without phasic vagal stretch receptor feedback has been studied in cats under light pentobarbitone anesthesia by electrical stimulation in the rostral pons using brief tetanic stimulation (300 Hz for 0.2 s). The threshold strength required just to elicit inspiratory ‘off‐switch’ was high early in inspiration and fell steeply with time. The threshold curves were steeper with than without phasic vagal feedback, and the difference reflects the phasic vagal contribution to the excitability of the inspiratory ‘off‐switch’ mechanism. In the absence of phasic vagal feedback the time course of this threshold curve usually corresponded closely to that of the ‘integrated’ phrenic activity at all PCO2levels and body temperatures tested indicating that the ‘integrated’ phrenic activity can be used as an index of the centrally generated inspiratory activity. In response to a rise in PCO2both the rate of change of the excitability of the inspiratory ‘off‐switch’ mechanism and its initial threshold level was increased. Changes in body temperature caused no change in the initial threshold but produced marked changes in the rate of rise of the ‘off‐switch’ excitability. Following an ‘augmented breath’ the inspiratory

ISSN:0001-6772    

DOI:10.1111/j.1748-1716.1976.tb10250.x

出版商:Blackwell Publishing Ltd    

年代:1976

数据来源: WILEY

摘要:

AbstractGastric acid secretion was measured in swimming codfish surgically equipped with a catheter draining the stomach. Intramuscular injection of histamine (15.6μg/kg·h) or carbachol (5μg/kg·h) stimulated the secretion of acid, carbachol in addition caused a marked decrease in drinking rate of the fishes. Administration of 10μmol/kg·h metiamide completely prevented the acid secretion induced by both drugs. The carbachol effect on the drinking rate, interpreted to mirror contraction of the stomach following stimulation of muscarinic receptors, was not affected by meti

ISSN:0001-6772    

DOI:10.1111/j.1748-1716.1976.tb10251.x

出版商:Blackwell Publishing Ltd    

年代:1976

数据来源: WILEY

摘要:

AbstractInfusions of hypertonic NaCl solution into the CSF of the lateral cerebral ventricle of the goat caused a marked reduction in parotid salivary flow concomitant with a rise in salivary [Na+]. Corresponding infusions of iso‐ or hypertonic glucose and glycerol solutions affected salivary secretion in the opposite direction. The possibility is discussed that a periventricular sodium‐sensitive mechanism, which is of importance in the central control of fluid balance, also may participate in the regulation of parotid secretion in the goat. This interpretation of the results is to some extent obscured by the observation of a high incidence of intermittent rumination during the intraventricular infusions of glucose and glycerol solut

ISSN:0001-6772    

DOI:10.1111/j.1748-1716.1976.tb10252.x

出版商:Blackwell Publishing Ltd    

年代:1976

数据来源: WILEY

摘要:

AbstractUnidirectional K+fluxes were measured in suspensions of isolated rat liver parenchymal cells incubated with42K+in vitro. By tracer exchange analysis fluxes in both directions were estimated to 8–9 10‐12mol/cm2. Glucagon in concentrations above 2 × 10‐8M increased both influx and efflux to 160% of control values. Insulin increased influx by 12–14 %, whereas efflux was apparently unaffected. Using an extracellular marker51Cr EDTA, intracellular level of some ions was estimated in isolated liver cells: K+= 172 mmol/kg water, Na+= 25 mmol/kg water, CI = 53 mmol/kg water. Cellular water content: 60%. Incubation with insulin for 1 h increased the intracellular concentration of K+1.7 mmol/kg water. The results indicate that glucagon increases primarily the K+‐permeability of the cell membrane, while insulin stimulates active K+transport int

ISSN:0001-6772    

DOI:10.1111/j.1748-1716.1976.tb10253.x

出版商:Blackwell Publishing Ltd    

年代:1976

数据来源: WILEY

摘要:

AbstractThe uptake and efflux of3H‐bretylium in slices of the rat vas deferens were examined. The uptake of bretylium was temperature, Na+and Cl‐dependent, sensitive to 6‐hydroxydopamine but insensitive to reserpine. The uptake was inhibited by desipramine, (+)‐amphetamine, imipramine methiodide and cocaine, whereas the local anaesthetics millicaine and lidocaine were poor inhibitors. The spontaneous efflux was very slow at 0°C and slow at 37°. Desipramine accelerated the efflux probably by inhibiting the re‐uptake of bretylium. (+)‐Amphetamine, low external Na+, high external K+and ouabain caused a pronounced increase in the efflux at 37°C but was almost without effect at 0°C. The efflux evoked by (+)‐amphetamine, low Na+and ouabain was inhibited by desipramine, imipramine methiodide and cocaine, whereas millicaine and lidocaine had very poor effects. The increase of bretylium efflux by hypertonic K+was only slightly inhibited by desipramine and partially antagonized by omission of Ca2+in the medium. The results obtained indicate that bretylium was taken up in noradrenergic neurones by the noradrenaline transport mechanism and that the efflux of bretylium produced by (+)‐amphetamine, low external Na+, low external Cl‐and by ouabain occurred by the same transport mechanism as the uptake but now working in the outward direction whereas the efflux induced by high K+seemed to occur mainly w

ISSN:0001-6772    

DOI:10.1111/j.1748-1716.1976.tb10254.x

出版商:Blackwell Publishing Ltd    

年代:1976

数据来源: WILEY

摘要:

AbstractIsolation of sensitized rat mast cells by density gradient centrifugation in Ficoll decreases the histamine release obtained when they are subsequently exposed to antigen. The histamine release from such isolated cells is potentiated by the addition of 2 % boiled rat serum. This potentiation is dose‐dependent and has a temperature optimum of about 25°C. The potentiating activity was localized to the serum phospholipid fraction. Of the pure phospholipids studied (LPC, PC, PE, PI, PS and SM) only phosphatidylserine and lysophosphatidylcholine were found to potentiate the histamine release. The mechanism behind this potentiation is discussed and it is suggested that the potentiation by phosphatidylserine and lysophosphatidylcholine is due to a requirement of these phospholipids for the ion exchange (Na+, K+and Ca++) or the adenylcyclase activity essential for the histamine release proce

ISSN:0001-6772    

DOI:10.1111/j.1748-1716.1976.tb10255.x

出版商:Blackwell Publishing Ltd    

年代:1976

数据来源: WILEY