Metabolism of mammary, abdominal, and femoral adipocytes in women before and after menopause

Abstract

In 23 women before and 11 after menopause, adipocyte size, lipoprotein lipase activity, and lipolytic responsiveness to norepinephrine were compared in different regions of adipose tissue. In premenopausal women femoral adipocytes were characterized by a higher lipoprotein lipase activity than abdominal or mammary adipocytes. On the other hand, lipolytic responsiveness and sensitivity in the latter two was higher than in femoral tissue. In postmenopausal women no differences in lipoprotein lipase or lipolysis were found among the three regions. Consequently, menopause in women seemed to be associated with a diminution of not only the increased lipoprotein lipase activity of femoral adipocytes, but also of the high lipolytic response in abdominal and mammary adipose tissue. It is therefore suggested that female sex steroid hormones exert regionally specific effects, ie, increasing lipoprotein lipase in femoral adipocytes, which therefore become enlarged. It also seems possible that stimulation of lipolysis in abdominal and mammary adipocytes is an effect of sex steroid hormones. From the results obtained it is hypothesized that the secondary sex characteristics of adipose tissue distribution in women might be caused by regionally specific effects of sex steroid hormones on adipocyte metabolism.