Vasoconstrictor effect of high FFA/albumin ratios in adipose tissuein vivo

BÜLOW, J., MADSEN, ASTRUP, A. & CHRISTENSEN, N.J. 1985. Vasoconstrictor effect of high FFA/albumin ratios in adipose tissue in vivo. Acta Physiol Scand 125, 661–667. Received 7 December 1984, accepted 17 June 1985. ISSN 0001–6772. Department of Clinical Physiology/Nuclear Medicine, Institute of Medical Physiology C, Copenhagen, Department of Internal Medicine and Endocrinology, Herlev, Denmark. Subcutaneous or perirenal adipose tissue blood flow was measured with the 133 Xe‐washout technique before and after intravenous injection or infusion of Intralipid* in six anesthetized, otherwise intact mongrel dogs. In four anesthetized mongrel puppies adipose tissue blood flow was measured with the radioactive microsphere method in seven different adipose tissue depots before a bolus injection of Intralipid and at the time after the injection when the thermogenic effect of the Intralipid was maximal. The results showed that the vascular resistance increased in all the examined adipose depots in adult as well as in young dogs after this treatment. The administration of Intralipid did not per se induce the vasoconstriction. The vasoconstriction took place simultaneously with increasing FFA/albumin molar ratios. The results support our previous findings in perfused fat pads that high molar FFA/albumin ratios increase vascular resistance in adipose tissue and they give further support to our suggestion that this vasoconstriction may be a link in a negative‐feedback mechanism regulating FFA‐mobilization in relation to FFA utilization.