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Horm Metab Res 1974; 6(3): 229-233
DOI: 10.1055/s-0028-1093859
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© Georg Thieme Verlag KG Stuttgart · New York

The Effect of Catecholamines and Fasting on Cyclic-AMP and Release of Glycerol from Human Adipose Tissue

C. H. Gilbert , D. J. Galton
  • Diabetes Research Laboratory, St. Bartholomew's Hospital, London, E.C.1, England
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Publication Date:
08 January 2009 (online)

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Abstract

The effects of catecholamines and fasting on levels of cyclic AMP and release of glycerol from human adipose tissue have been studied. Isoprenaline (10-5 M) produced a prompt rise and fall in levels of cyclic-AMP associated with release of glycerol and fatty acids into the medium. Noradrenaline (10-4 M) had a similar effect which was potentiated by phentolamine (an α-adrenergic blocker). Insulin (10-8 M) reduced tissue levels of cyclic-AMP and release of glycerol that had been stimulated by isoprenaline (10-7 M). However, at higher doses of insulin (10-7 M) the reverse tendency was noted. Prostaglandins E1, E2 and A2 likewise inhibited the release of glycerol and reduced tissue levels of cyclic-AMP, whereas prostaglandins A1 and F2α were without effect. However, a period of fast (10 days) activated lipolysis as judged by an increase in basal release of glycerol without altering tissue levels of cyclic-AMP. Furthermore, at the end of the fast, isoprenaline still stimulated release of glycerol and increments in cyclic-AMP to a similar extent as before fasting. This suggests that lipolysis produced by fasting may not be dependent on stimulation of triglyceride-lipase by cyclic-AMP, since the lipase is still in an activatable state at the end of a fast.

Key words

Human Adipose Tissue - Lipolysis - Catecholamines - Cyclic-AMP - Prostaglandins - Fasting

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