Evolution of the sensitivity of isolated adipocytes of ewes to the antilipolytic action of adenosine during pregnancy and lactation.

Four successive biopsies of omental adipose tissue were performed on the 43rd, 100th, 140th days of pregnancy and during the 3rd week of lactation in 6 "Pré-Alpes" ewes. Using incubated isolated adipocytes, we studied the evolution of the antilipolytic effect of adenosine. Adenosine presented a significant inhibitory effect on basal lipolysis only at the end of pregnancy. The antilipolytic effect of adenosine on the stimulated lipolysis by a beta-agonist (isoproterenol 400 nM) increased during pregnancy. The maximal effect was observed 1 week before parturition. The level of inhibition remained high during lactation. The lipolytic effect of adenosine-deaminase was enhanced during pregnancy and lactation and evolved similar to the observed action of adenosine. Results suggest that the antilipolytic action of adenosine may have a physiologic importance.