Fat mobilization in adipose tissue of weaning rats with hypothalamic obesity.

In vitro lipolysis (glycerol release), hormone-sensitive lipolytic activity and free fatty acid (FFA) release as well as the response of these parameters to adrenaline, were studied inadipose tissue of obese weanling rats with electrolytic lesions in the hypothalamic ventromedial nuclei (VMN). In the absence of adrenaline, adipose tissue from weanling VMN rats showed neither depressed lipolysis nor diminished lipolytic activity per mg of tissue protein, and esterification appeared to be equal to lipolysis since there was no FFA release. Adrenaline augmented lipolysis and hormone-sensitive lipolytic activity to the same extent in VMN as in control tissue, but produced an overall release of FFA which was significantly less in VMN than control. The lesser FFA release in the VMN tissue compared to control may be a result of greater utilization of FFA, by oxidation or for esterification, by that tissue when stimulated by adrenaline.