AJP - Endocrinology and Metabolism, Vol 239, Issue 6 422-E429, Copyright © 1980 by American Physiological Society

ARTICLES

Mechanism of enhanced lipolysis in adipose tissue of exercise-trained rats

L. Bukowiecki, J. Lupien, N. Follea, A. Paradis, D. Richard and J. LeBlanc

The effects of exercise training and food restriction on the regulation of lipolysis were studied comparatively in adipocytes isolated from male and female rats. Exercise training inhibited cell proliferation in parametrial, but not in epididymal adipose tissue, whereas it significantly reduced adipocyte size in both fat depots. Adipocyte capacity for responding lipolytically to epinephrine (10 microns) or to ACTH (1 micron) was markedly increased by exercise training. Enhanced lipolysis was also observed when cells isolated from exercise-trained animals were stimulated by bypassing with dibutyryl cyclic AMP (5 mM) or theophylline (5 mM) the early metabolic steps associated with hormonal activation of the adenylate cyclase complex. Significantly, binding of (-)-[3H]dihydroalprenolol to cellular receptor sites was not affected by exercise training. It is therefore concluded that exercise training increases adipocyte responsiveness to lipolytic hormones at a metabolic step distal to stimulus recognition by adrenoreceptors, possibly at the level of protein kinases or lipases. Food restriction markedly reduced adipocyte size and partially mimicked the effects of exercise training on adipocyte proliferation and lipolysis.

This article has been cited by other articles:

				L. H. Enevoldsen, B. Stallknecht, J. D. Fluckey, and H. Galbo Effect of exercise training on in vivo lipolysis in intra-abdominal adipose tissue in rats Am J Physiol Endocrinol Metab, September 1, 2000; 279(3): E585 - E592. [Abstract] [Full Text] [PDF]

				G. B. Carey Cellular adaptations in fat tissue of exercise-trained miniature swine: role of excess energy intake J Appl Physiol, March 1, 2000; 88(3): 881 - 887. [Abstract] [Full Text] [PDF]