Free fatty acids of plasma during head-up tilting (orthostatic stimulation). Studies in normal persons, patients with postural hypotension and anaesthetized dogs

Effect of reflex stimuli on vascular resistance and glycerol release in in vivo dog subcutaneous adipose tissue

Although direct autonomic nerve stimulation and infusion of catecholamine has been shown to result in substantial amounts of lipolysis in dog subcutaneous adipose tissue, there is no evidence to indicate that reflex autonomic stimulation will result in qualitatively and quantitatively similar changes. The present studies were performed to evaluate the effects of reflex autonomic stimulation on vascular resistance and glycerol release in isolated, innervated and blood-perfused subcutaneous fat pad. Autonomic nerve stimulation at physiological frequencies was performed and resulted in release of glycerol that was compatible with previously reported data. Reflex stimulation by moderate and severe hypoxemia did not result in a significant glycerol release, but a maximal reflex stimulus (ventricular fibrillation) did. Since the majority of these reflex stimuli resulted in large change in vascular resistance, it would appear that reflex hemodynamic changes can occur in these preparations without concomitant changes in glycerol release. Alpha blockade of the vasoconstriction resulted in the appearance of rising glycerol output suggesting that vasoconstriction prevents lipolysis.