Effects of prazosin on human fat-cell lipolysis and adenylate cyclase activity in vitro.

The effects of prazosin on adrenergic-stimulated fat-cell lipolysis and adenylate cyclase activity were investigated. The results revealed that the antilipolytic alpha-adrenergic catecholamine effects on human fat-cell metabolism are mediated via alpha 2-receptor sites displaying extremely low affinity to prazosin, which is alpha 1-site selective. The data provide an explantation for the lack of effect of prazosin on lipid mobilization in vivo. The molecular sites mediating the lipid-lowering action of the drug, however, remain to be elucidated.