INTRACAVERNOUS PRESSURES INCREASES AND PE RINEAL MUSCLES CONTRACTIONSIN RESPONSE TO PRESSURE STIMULATIONS OF THE GLANS-PENIS

The role of the perineal muscles in human penile erections is still co ntroversial. The authors investigated surface electromyographic activi ty of the ischiocavernous muscles together with intracavernous pressur e recordings during pressure stimulations of the glans penis. Successi ve glans stimulations were associated with ischiocavernous muscle cont ractions and increases in intracavernous pressure reaching two- to fou rfold the systolic blood pressure. High correlation coefficients were found between electromyographic and intracavernous pressure amplitudes . Voluntary contractions were accompagnied by intracavernous pressure peaks of similar durations, and areas delineated by integrated electro myographic and intracavernous pressure curves showed very high correla tion coefficients. Anaesthesia of the dorsal nerve resulted in dramati c reductions of muscle activity and intracavernous pressures in respon se to glans stimulation. These results suggest that the activity of th e muscles in response to pressure stimulation of the glans penis is im portant to augment rigidity during vaginal penetration and intercourse due to their ability to increase intracavernous pressures.