The development of lipolytic sensitivity in the isolated fat cells of gallus domesticus during the foetal and neonatal period

Abstract

1. 1. The development of lipolytic sensitivity in chicken adipocytes obtained from 14- to 20-day-old foetuses and 0- to 15-day-old chicks was studied. 2. 2. The lipolytic sensitivity to glucagon increased until the bird hatched and thereafter remained constant. The maximum rate of lipolysis increased similarly. 3. 3. Dibutyryl cyclic AMP stimulated lipolysis at all ages whereas noradrenaline, caffeine and theophylline stimulated lipolysis only in adipocytes from hatched birds. Cyclic AMP alone failed to stimulate lipolysis. However, both caffeine and theophylline potentiated glucagon-stimulated lipolysis in foetal adipocytes. 4. 4. It is suggested that the increase in lipolytic sensitivity is due both to a fall in phosphodiesterase activity and an increased capacity for cyclic AMP production.