Adrenal and sympathetic catecholamines in exercising rats

Abstract

Adrenal and sympathetic catecholamines in exercising rats Scheurink, A.J.W.; Steffens, A.B.; Bouritius, H.; Dreteler, G.H.; Bruntink, R.; Remie, R.; Zaagsma, J.

Metabolic and hormonal responses to hypothalamic administration of norfenfluramine in rats

“…In contrast, the exercise-induced increase in plasma NE levels was significantly lower in the NFFL-treated animals when compared with the aCSF-infused control rats. In the latter group, plasma NE levels increased up to 2.7 + 0.3 ng/ml at t = 45 rain, which is similar to control values obtained in previous studies in our lab (36). On the other hand, the exercise-induced increase in plasma NE remained relatively low in the NFFL-treated animals; the maximum of 2.0 -+ 0.3 ng/ml after 15 min of swimming was markedly reduced in comparison to the concentrations reached in the control group (Fig.…”

“…Plasma insulin levels were decreased during swimming. The exerciseinduced changes in the blood components were very similar to the changes described for the control animals in previous studies from our laboratory (36,37). Intrahypothalamic infusion of NFFL before exercise increased blood glucose and plasma E concentrations, and failed to influence plasma concentrations Number of rats in brackets.…”

Vascular adaptive responses to physical exercise and to stress are affected differently by nandrolone administration

“…This view is supported by the observation that removal of the endothelium abolished the decreased response of the aorta to noradrenaline that had been induced by the training protocol. A similar hyperactivity of endothelial cells was previously reported in conditions that, like physical exercise (33,34), involve prolonged activation of adrenoceptors such as stress, barodenervation, and pheochromocytoma (15,19,35). In fact, the acute exposure to stress reduced the aortic reactivity to noradrenaline of sedentary rats that was abolished by endothelium removal.…”

Autonomic regulation of islet hormone secretion - Implications for health and disease

“…The combined action of the adrenals and the sympathetic nerves could also be explained by a sequential action. Thus it has been shown in swimming rats that adrenaline released from the adrenals stimulates the local release of noradrenaline from the islet nerve terminals through a b 2 -adrenoceptor-mediated action [166]. Noradrenaline might therefore be released both by direct sympathetic activation and indirectly by a presynaptic inhibition of re-uptake induced by adrenaline.…”

“…These changes are partially prevented by ganglionic blockade, by a-adrenoceptor antagonism and by sympathetic denervation by 6-hydroxydopamine. This indicates they are mediated by activation of the sympathetic nerves through adrenergic mechanisms [165,166]; sympathetic nerve activation inhibits insulin and stimulates glucagon secretion (see above). Mice were pretreated with a high-titre galanin antiserum to examine whether the remaining part of the inhibition of glucose-stimulated insulin secretion during swimming stress is mediated by sympathetic neuropeptides.…”