Nitric Oxide Independent Activation of Guanylate Cyclase by YC-1 Causes Erectile Responses in the Rat

Purpose: Activation of soluble guanylate cyclase with a subsequent increase in intracellular levels of cyclic guanosine monophosphate is necessary for normal erection. In vascular tissue 3(5′-hydroxymethyl-2′-furyl-1-benzyl indazole (YC-1) (Abbott Laboratories, North Chicago, Illinois) has been shown to stimulate soluble guanylate cyclase independent of nitric oxide. We studied whether YC-1 modulates erectile responses in the rat.Materials and Methods: The effects of YC-1 given intracavernously or intraperitoneally on intracavernous pressure were investigated in rats. Functional effects of YC-1 on neuronal and endothelial nitric oxide relaxations were studied in 3 × 10−6 M. 1-noradrenaline contracted preparations of rat isolated corpus cavernosum.Results: Intracavernous YC-1 (10 μmol. kg.−1) produced erectile responses with a mean intracavernous pressure plus or minus standard error of mean of 81 ± 17 cm. water (p