Antilipolytic activity of viprostol, a transdermally active antihypertensive PGE2 analog

Viprostol, a novel prostaglandin E₂ congener, was assessed for antilipolytic activity in the spontaneously obese rat. In isolated epididymal adipocytes, viprostal exhibited a dose-dependent inhibition of catecholamine-stimulated lipolysis at concentrations ranging from 10 μM to 1 mM, but was ineffective at lower concentrations. Additionally, viprostal exhibited approximately 50% of the antilipolytic activity of naturally-occurring PGE₁ and PGE₂ at similar concentrations, but was as potent as PGF_2α. At 10 μM, viprostol inhibited maximum catecholamine-stimulated lipolysis by approximately 35% of the total, hormone-stimulated glycerol release. The results of these experiments indicate that viprostol exhibits antilipolytic activity , but is less potent than the naturally-occurring PGE's to which it is most closely related structurally.