摘要:

The uptake of 14C-angiotensin was studied in canine cutaneous blood vessels in vitro. T/M ratios of 14C were 0.4, 0.5, 0.8 and 1.5 after 7.5, 15, 30 and 60 min of incubation, respectively. The T/M of 14C-sorbitol, an extracellular marker, was 0.4. No difference in the T/M ratios of C14 was found between normal and chronically denervated vessels incubated with 14C-angiotensin; however, the uptake of 3H-norepinephrine was markedly decreased in the denervated preparation. The 14C taken up by the vessels after 30 min of incubation appeared to comprise both intact angiotensin and metabolites. These results suggest that a small quantity of intact angiotensin may be bound by vascular tissue, but is not concentrated in adrenergic nerve endings.

ISSN:1018-1172    

DOI:10.1159/000158040

出版商:S. Karger AG    

年代:1975

数据来源: Karger

摘要:

Canine lateral saphenous vein and human greater saphenous vein were studied together to determine similarities and differences. Helical strips of both vessels contracted to norepinephrine with similar sensitivity. Canine veins developed more isometric tension than human veins treated similarly. Histological studies show canine veins to have little connective tissue and a single circular layer of smooth muscle. Human veins have much connective tissue and three layers of smooth muscle, an inner circular layer, middle longitudinal layer and outer circular layer.

ISSN:1018-1172    

DOI:10.1159/000158041

出版商:S. Karger AG    

年代:1975

数据来源: Karger

摘要:

Vasogenic cerebral edema was induced in rabbits by cold injury. Benzopyrone treatment, started 15 min after freezing, significantly reduced both brain edema and the increased permeability of the blood-brain barrier. On the other hand benzopyrone-treatment was without any effect in cytotoxic brain edema induced in rats by triethyl tin poisoning.

ISSN:1018-1172    

DOI:10.1159/000158042

出版商:S. Karger AG    

年代:1975

数据来源: Karger

摘要:

The disposition of sympathetic transmitter within the wall of rat femoral and rabbit saphenous arteries has been studied during sympathetic stimulation. Using a histochemical fluorescence technique, sharply delineated bead-like fluorescent spots representing sympathetic nerve terminals were found at the adventitiomedial junction. In specimens excised during sympathetic nerve stimulation, the entire media was veiled by fluorescent material representing noradrenaline which had diffused into that layer after release. The localization of the nerve terminals in controls as well as diffusion of transmitter during stimulation in the rat femoral artery was corroborated by autoradiography of tritiated noradrenaline.

ISSN:1018-1172    

DOI:10.1159/000158043

出版商:S. Karger AG    

年代:1975

数据来源: Karger

摘要:

The effects of phenoxybenzamine and norepinephrine (NE) on the release of tritiated NE were studied in spiral strips of the rabbit pulmonary artery. Phenoxybenzamine increased the tritiated NE efflux induced by transmural stimulation at 4 Hz by a factor of three. The magnitude of this effect was inversely related to the frequency of stimulation. NE (2.5 × 10–6 m) decreased the enhancing effect of short exposure but not long exposure to phenoxybenzamine, probably by surmounting the phenoxybenzamine blockade of the α-adrenergic receptors on the adrenergic nerve terminal. The transmitter output per pulse increased with the frequency from 4 to 16 Hz and decreased at 32 Hz. This evidence suggests that a negative feedback mechanism does operate in this vascular preparation but, probably because of the wide neuromuscular cleft, is less effective than in tissues with a narrower synaptic inter

ISSN:1018-1172    

DOI:10.1159/000158044

出版商:S. Karger AG    

年代:1975

数据来源: Karger

ISSN:1018-1172    

DOI:10.1159/000158045

出版商:S. Karger AG    

年代:1975

数据来源: Karger