title: Blood gas analysis in drug-induced penile erection.
abstract: To elucidate the hemodynamic changes during erection, we measured corporeal blood gases in 6 monkeys before, during, and after erection induced by either papaverine or phentolamine or a combination of the two. Papaverine alone caused a strong erection (maximal tumescence and rigidity) by means of a rapid, large increase in pO2 and pCO2 with a pH drop to the acidic range. Phentolamine alone caused 'delayed' tumescence with less rigidity; the intracorporeal pO2 level increased, but pCO2 and pH values did not change significantly. The combination of both drugs offered no advantage over papaverine alone. We conclude that papaverine is a potent erection-inducing drug that acts in a bimodal manner, namely, it increases the arterial inflow and, at the same time, decreases the venous outflow. Phentolamine affects the arterial component of erectile function only.
mesh_terms: D000818:Animals; D001784:Blood Gas Analysis; D004338:Drug Combinations; D008252:Macaca fascicularis; D008297:Male; D010208:Papaverine / Q000494:pharmacology*; D010410:Penile Erection / Q000187:drug effects*; D010646:Phentolamine / Q000494:pharmacology*
chemical_list: D004338:Drug Combinations; D010208:Papaverine; D010646:Phentolamine