CELL SIZE AND LIPOLYSIS BY HUMAN SUBCUTANEOUS ADIPOSE TISSUE

Abstract
Specimens of human subcutaneous adipose tissue were removed from subjects with marked difference in body weight, patients with recent onset of diabetes mellitus of juvenile and adult type, and from obese subjects before and after intestinal shunt operation. The production of glycerol by sections of adipose tissue of the non‐diabetics under basal (glucose cone. 5.5 mM) as well as stimulated conditions was positively correlated to the mean cell volume estimated according to the histiometric procedure. The maximal lipolytic responses to theophylline and N6,O2‐dibutyryl 3′5′ AMP, expressed as the relative change in the glycerol production above the basal values, were negatively related to the mean cell volume. The addition of the α‐adrenergic blocking agent phentolamine increased more markedly the noradrenalineinduced glycerol production by small fat cells than that by enlarged cells. The findings clearly show that the size of the fat cells has a substantial influence on the lipolysis of human fat cells. Adipose tissue of large cells might respond with less marked lipid mobilization than adipose tissue composed of small cells. This could be of relevance for the understanding of the non‐ketotic hyperglycemic syndrome.