Sympathetic nerve stimulation in dog subcutaneous adipose tissue induces alpha-receptor mediated vasoconstriction and beta-receptor mediated vasodilatation.
Abstract The subcutaneous adipose tissue in the lower abdominal region between the pubis and the pubic mammary gland was isolated from fascia and skin and prepared for direct measurement of the blood flow. Resting blood flow varied between 3 and 19ml/min ˙ 100g adipose tissue (mean 8.5ml/min ˙ 100g; n = 17). Stimulation of the nerve supplying the adipose tissue or of the sympathetic trunk induced a stimulus‐frequency related vasoconstriction which was abolished by agents with α‐receptor blocking properties. Following α‐receptor blockade the same nerve stimulation increased the blood flow to a maximum of about 25ml/min ˙ 100g. The degree of vasodilatation was also related to the stimulus frequency. Propranolol, a β‐receptor blocking agent, abolished the vasodilator response. Reflex adjustment of the peripheral vasomotor tonus upon carotid artery occlusion and activation of the sympathetic cholinergic vasodilator nerves in the hypothalamus did not appreciably change the vascular resistance in the adipose tissue.
Ngai et al. (Tue,) studied this question.