摘要:

AbstractThe rate of uptake of the non‐utilizable monosaccharide 3‐O‐methylglucose was studied in isolated ovaries from prepubertal rats. It was found that puromycin, added to the incubation medium in a concentration which completely blocked the protein synthesis, markedly decreased the rate of uptake of 3‐O‐methylglucose. It was also found that addition of luteinizing hormone (LH) to the incubation medium still increased the rate of uptake of 3‐O‐methylglucose when the protein synthesis was blocked

ISSN:0001-6772    

DOI:10.1111/j.1748-1716.1969.tb04570.x

出版商:Blackwell Publishing Ltd    

年代:1969

数据来源: WILEY

摘要:

AbstractThe mechanism of increased work performance resulting from “diverting works” was examined. Muscle blood flow was measured in exercised and rested muscles by means of venous occlusion plethysmography and133Xe clearance. Measurements of muscle blood flow, blood pressure and work performance following “diverting work” and other stimuli were compared with values obtained during control rest periods. Stimuli which caused a substantial rise in arterial blood pressure (“diverting work”, change in heart level, pain) caused increases in blood flow and work performance in exercised muscles. Non‐pressor or mild pressor stimuli (non‐strenuous “diverting work”, CO2inhalation, apnea, cold) resulted in unchanged blood flow and work values in the exercised muscles. It is concluded that pressor stimuli produce increased muscle blood flow in maximally ischemic muscles due to release of muscle arteries from neurogenic and myogenic control. The increased muscle blood flow during periods employing pressor stimuli results in improved muscle restitution and hence increase

ISSN:0001-6772    

DOI:10.1111/j.1748-1716.1969.tb04571.x

出版商:Blackwell Publishing Ltd    

年代:1969

数据来源: WILEY

摘要:

AbstractIn the frog skin epithelium the amount of radio‐sodium originating from the outside solution has been determined under different experimental conditions. It has been found that this sodium‐pool behaves largely as a pool in which the sodium has passed the transport mechanism. It has not been possible under any of the conditions used to demonstrate the existence of epithelial radio‐sodium awaiting active transport. This finding leads to the conclusion that the mechanism for active transport of sodium is effective at the outer surface of the frog

ISSN:0001-6772    

DOI:10.1111/j.1748-1716.1969.tb04572.x

出版商:Blackwell Publishing Ltd    

年代:1969

数据来源: WILEY

摘要:

AbstractChanges of cell volume in the smooth muscle of the isolated rat portal vein, produced by variations in extracellular osmolarity, are associated with characteristic changes in the spontaneous electrical and mechanical activity of the preparation (Johansson and Jonsson 1968, Arvill, Johansson and Jonsson 1969). An analysis of such responses to anisosmotic solutions containing different non‐electrolytes was carried out in the present study in order to elucidate the osmotic influences of the test substances on the vascular smooth muscle cells. The time course of the responses revealed the following relative rates of penetration through the cell membranes: sucrose

ISSN:0001-6772    

DOI:10.1111/j.1748-1716.1969.tb04573.x

出版商:Blackwell Publishing Ltd    

年代:1969

数据来源: WILEY

摘要:

AbstractVarious nucleotides and metabolic inhibitors have been tested on the release, reuptake and net uptake of noradrenaline (NA) in isolated splenic nerve granules. Cytidine, inosine, and uridine triphosphate facilitated uptake of NA to a similar degree as adenosine diphosphate but less than adenosine triphosphate. Cyclic AMP had no effect.Various inhibitors of the respiratory chain and oxidative phosphorylation (rotenone, chlorpromazine, antimycin and oligomycin) inhibited both release and uptake of NA at 10–3–10–4M. Atractylate had no action at 10–3M. Cyanide and azide at 10–3M had no or a slight action only.The uncouplers dinitrophenol, carbonyl cyanidem‐chlorophenyl hydrazone, desaspidin, and pentachlorphenol all increased the release rate of NA from granules and inhibited reuptake.The results suggest that the ATP facilitated uptake process requires electron transport and that the ability of the granules to retain bound NA is dependent on an energized state of the system. At least certain steps of electron transport‐coupled phosphorylation occurring in mitochondria appear to be involved in amine release and uptak

ISSN:0001-6772    

DOI:10.1111/j.1748-1716.1969.tb04574.x

出版商:Blackwell Publishing Ltd    

年代:1969

数据来源: WILEY

摘要:

AbstractGastric secretion was stimulated by sham feeding in Pavlov pouch dogs with esophageal fistulae and isolated pouches of the duodenal bulb. Reduction of the intrabulbar pH to pH 3–4 inhibited the acid response to sham feeding. Bulbar acidification was more effective in inhibiting acid responses to 1 and 10 min of sham feeding than responses to 30 min of sham feeding. Short periods of bulbar acidification were sufficient to activate the bulbar inhibitory mechanis

ISSN:0001-6772    

DOI:10.1111/j.1748-1716.1969.tb04575.x

出版商:Blackwell Publishing Ltd    

年代:1969

数据来源: WILEY

摘要:

AbstractAdrenergic receptor function in the human ductus arteriosus has been demonstrated byin vitroperfusion and spiral strip experiments and correlated with the finding of specific adrenergic nerve fibers in the smooth muscle layer of the media by histochemical fluorescence technique. The results support the possible role of an adrenergic mechanism involved in the closure of the ductus in neonates.

ISSN:0001-6772    

DOI:10.1111/j.1748-1716.1969.tb04576.x

出版商:Blackwell Publishing Ltd    

年代:1969

数据来源: WILEY

摘要:

AbstractThe uptake and distribution in mice of rubidium‐86 (86Rb) and potassium‐43 (43K) was studied using whole body autoradiographic techniques. In addition, a microautoradiographic study of the distribution of86Rb in the heads of rats was made. The results demonstrate high relative accumulation of86Rb in hyaline and articular cartilage, tendon, forming bone, liver, pancreas, salivary glands, thymus, spleen and skeletal muscle. At one hour post‐injection, the distribution pattern of43SK was similar to but much less differentiated than that of86Rb. Relatke to the accumulation of each in skeletal muscle,86Rb was more concentrated than43K in hyaline and articular cartilage, tendon and liver, while the converse was seen in heart muscle, lung, bone and brain. The micro‐autoradiograms demonstrated high relative uptake of86Rb in trahecular bone and the dentin and enamel of unerupted teeth. The results of the present study have been compared to those of previously published quantitative studies on the accumulation of86Rb and42K, and the results were found to be in close agreement. In addition, the present results demonstrate high relative accumulation of86Rh and48SK in hyaline and articular cartilage, tendon and forming bone, and high86Rb concentrations in forming teeth and foetal bone and cartilage, observations which hale not been made in earlier studies. The similarities to and differences from the results of a similar study of the uptake and distribution of caesium‐137 (137Cs) are

ISSN:0001-6772    

DOI:10.1111/j.1748-1716.1969.tb04577.x

出版商:Blackwell Publishing Ltd    

年代:1969

数据来源: WILEY

摘要:

AbstractOxygen uptake in dog skeletal muscle was studied upon activation of the sympathetic cholinergic vasodilator nerves, upon reflex inhibition of the peripheral vasoconstrictor nervous tone and as a response to i.a. acetylcholine infusion. Oxygen uptake was calculated from the arteriovenous oxygen saturation and the blood flow. Stimulation of the hypothalamic vasodilator area or of the sympathetic lumbar chain, after adrenergic nervous blockade, produced an increased blood flow and a rise in calculated oxygen uptake in the muscle. In most animals the oxygen uptake returned to, or went slightly below, pre‐stimulatory levels after an initial increase for about 30 sec. However, in some experiments the oxygen uptake was elevated during the whole period of vasodilatation. Reflex inhibition of vasoconstrictor tone was produced in crosscirculation experiments by stimulating the carotid sinus nerve of the recipient dog. When the stimulation resulted in a blood flow rise in the cross‐circulated muscle, the oxygen uptake in the muscle remained increased during the whole period of vasodilatation. Acetylcholine was infused i.a. to produce vasodilatations comparable to those induced by vasodilator nerve stimulation or reflex inhibition of vasoconstrictor tone. A blood flow rise was accompanied by an initial brief inctease of the oxygen uptake followed by a return to resting values. It is concluded that sympathetic cholinergic nervous stimulation and acetylcholine elicit changes in the oxygen uptake in skeletal muscle indicating an effect predominantly on precapillary resistance vessels and not, or to a much lesser extent, on precapillary sphincters. In contrast, by inhibition of vasoconstrictor nervous tone both precapillary resistance vessels and precapillary sphincters are dila

ISSN:0001-6772    

DOI:10.1111/j.1748-1716.1969.tb04578.x

出版商:Blackwell Publishing Ltd    

年代:1969

数据来源: WILEY

摘要:

AbstractThe subcellular distribution of exogenously administered3H‐noradrenaline in adrenergic nerves of mouse atria after pretreatment with nialamide, reserpine and nialamide, or the methylester ofa‐methyl‐p‐tyrosine (H44/68) has been investigated. Parallel fluorescence histochemical studies have been performed. Both reserpine and H44/68 cause a pronounced decrease in the endogenous noradrenaline stores. The subcellular distribution was practically identical in untreated, nialamide‐pretreated and H44/68‐pretreated animals; approximately 30%3H‐noradrenaline was recovered in the particulate fraction which in all probability contains the amine storage granules. In the reserpine‐nialamide pretreated mice, however, most of the3H‐noradrenaline was found in the supernatant iraction, and about 10 % in the particulate fraction. These studies thus confirm earlier investigations that reserpine is a potent inhibitor of the noradrenaline uptake in the amine storage granules, although there is a small reserpineresistant uptake. Furthermore, after tyrosine hydroxylase inhibition both the ‘membrane pump’ and the granular uptake mechanism seem to operate. The morphological studies disclosed differences in the adrenergic nerves when the noradrenaline taken up is mainly granularly or extragranularly stored, since the varicosities are in the former case distinct and the latter case less distinct, while the pre‐terminals are more prominent. Methodological studies of the homogenization procedure for subcellular distribution studies have also been performed, the results of which are discussed in view of the experimental data obtained.It is now well established, based on both biochemical and electronmicroscopic evidence. that the peripheral adrenergic transmitter NAIis mainly stored in special intraneuronal storage granules (Euler and Hillarp 1956. Schümann 1958. Camps and Shideman 1962. Potter and Axelrod 1962, Lundborg 1967, Hokfelt 1969). Exogenously administered NA is rapidly taken up by the axonal membrane of the adrenergic neuron and subsequently incorporated into the storage granules, mainly by means of an ATP‐Mg++‐dependent uptake mechanism. This latter process can be efficiently‐blocked by reserpine (Carlssonet al

ISSN:0001-6772    

DOI:10.1111/j.1748-1716.1969.tb04579.x

出版商:Blackwell Publishing Ltd    

年代:1969

数据来源: WILEY