Interrelationship of cyclic AMP, lipolysis, and respiration in brown fat cells.

FAIN, JOHN N., MARK D. JACOBS, AND YVONNE C. CLEMENT-, CORMIER. Interrelationship of cyclic AMP, Zipolysis, and respiration in brown fat cells. Am. J. Physiol. 224(Z): 346-351. 1973.-The marked stimulation of oxygen consumption in brown fat cells seen after the addition of norepinephrine is thought to be secondary to the stimulation of adenylate cyclase and result from a K+-dependent uncoupling action of free fatty acids released as a result of activation of lipolysis by cyclic AMP. The present studies indicate that there was a good correlation between the ability of catecholamines and serotonin (5-hydroxytryptamine) to affect cyclic AMP accumulation, lipolysis, and respiration. Propranolol, a beta-adrenergic antagonist, blocked the effects of both serotonin and norepinephrine. High concentrations of ouabain reduced the stimulation of cyclic AMP accumulation, lipolysis, and oxygen consumption by catecholamines but did not inhibit the effects of theophylline on lipolysis or cyclic AMP accumulation. The stimulation of respiration by added fatty acids was also unaffected by ouabain. Ouabain increased glucose conversion to carbon dioxide and decreased lactate accumulation.