Intracavernous pressure changes during reflexive penile erections in the rat.

Reflexogenic penile erections have been previously described in the rat. However, exact involvement of the corpus cavernosum in reflex responses is indefinite. We report changes in intracavernous pressure (ICP) recorded in 10 awake rats by means of a telemetric device. The ICP changes and penile reflex responses (lengthening of the penile body, glans erection, cup, and flip) were recorded during ex copula tests. Each type of penile response was characterized by a specific ICP variation. Mean maximal ICP increase during lengthening of the penile body was 58.6 mmHg, during glans erection 67.3 mmHg, during cups 99.1 mmHg, and 215.2 mmHg during flips. ICP increases to 35.1 mmHg immediately preceding each cluster of penile responses. This study provides quantitative data on the involvement of the corpus cavernosum during reflexive erections. Tumescence of the corpus cavernosum was present during glans erection and suprasystolic ICP peaks occurred during flips. ICP measurements during reflexive erections should bring new insights into the analysis of their physiological mediation.