ARE NEURONAL UPTAKE MECHANISMS RESPONSIBLE FOR THE DIFFERENCE IN SENSITIVITY TO NORADRENALINE BETWEEN HUMAN ARTERIES AND VEINS?
作者:
M. J. Stevens,
R. F. W. Moulds,
期刊:
Clinical and Experimental Pharmacology and Physiology
(WILEY Available online 1980)
卷期:
Volume 7,
issue 2
页码: 139-145
ISSN:0305-1870
年代: 1980
DOI:10.1111/j.1440-1681.1980.tb00055.x
出版商: Blackwell Publishing Ltd
关键词: cocaine;human digital arteries;neuronal uptake mechanisms;human veins;adrenoceptors
数据来源: WILEY
摘要:
SUMMARY1. The sensitivity of human metacarpal veins and digital arteries obtained post‐mortem to noradrenaline and phenylephrine has been tested.2.pED50values for noradrenaline were significantly higher in the veins (699, s.e.m. = 008) than in the arteries (6.56, s.e.m. = 009), whereaspED50values for phenylephrine in the two tissues were not significantly different (arteries: 6.24, s.e.m. = 009; veins: 6.26, s.e.m. = 005).3. The addition of propranolol (4 × 10−6mol/l) alone, or in combination with hydrocortisone (4 × 10−5mol/l), did not affect the responses to either noradrenaline or phenylephrine. The further addition of cocaine (3 × 10−5mol/l) slightly shifted the noradrenaline and phenylephrine concentration‐effect curves to the left in both arteries and veins, but veins were still found to be more sensitive than arteries to noradrenaline whilst there was still no difference in the sensitivity of veins and arteries to phenylephrine.4. Cocaine also slightly potentiated responses to barium chloride, potassium chloride and serotonin.5. It is concluded that the difference in sensitivity to noradrenaline between arteries and veins cannot be explained by differences in neuronal uptake and it is possible that there may be differences in the properties of the postsynaptic α‐adrenoreceptors of the two tissues. It is also concluded that the potentiation of the contractile effect of noradrenaline produced by cocaine is not solely due to inhibition of neuronal u
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