Glucagon and plasma catecholamines during beta-receptor blockade in exercising man.
Glucagon and plasma catecholamines during beta-receptor blockade in exercising man.
复制标题
运动男子β受体阻断期间的胰高血糖素和血浆儿茶酚胺。
DOI:
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发表时间:
1976
影响因子:
3.3
通讯作者:
J. Hilsted
中科院分区:
文献类型:
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作者:
H. Galbo;J. Holst;N. Christensen;J. Hilsted
Seven men ran at 60% of individual maximal oxygen uptake to exhaustion during beta-adrenergic blockade with propranolol (P), during lipolytic blockade with nicotinic acid (N), or without drugs (C). The total work times (83 +/- 9 (P), 122 +/- 8 (N), 166 +/- 10 (C) min, mean and SE) differed significantly. Epinephrine rose progressively above preexercise levels (0.06 +/- 0.01 ng/ml); at exhaustion concentrations in P experiments (2.15 +/- 0.41) were larger than in N (1.08 +/- 0.31) and C (0.72 +/- 0.28) experiments. Norepinephrine increased consistently while insulin decreased. After an initial decrease glucagon concentrations increased progressively in parallel with declining plasma glucose and were at exhaustion always three times preexercise values. Thus beta-adrenergic blockade did not diminish the glucagon response. Nor was this response increased when alpha-receptor stimulation in P experiments was intensified. Carbohydrate combustion was smaller and NEFA and glycerol concentrations in serum larger during C experiments. Alanine concentrations were never raised at exhaustion. Accordingly, neither stimulation of adrenergic receptors nor NEFA and alanine concentrations are major determinants for the exercise-induced glucagon secretion in man. It is suggested that decreased glucose availability enhances the secretion of glucagon and epinephrine during prolonged exercise.