Effects of i.c.v. injection of oxytocin antagonist (OT antag.) on the quantitative parameters of sexual responses induced by 7-OH-DPAT. Amplitude of ICP rises, expressed as percentage of MAP measured during the corresponding ICP rise, and duration of ICP rises were determined in rats pretreated, 15 min prior to i.c.v. 7-OH-DPAT (10 μg), with i.c.v. oxytocin antagonist vehicle, oxytocin antagonist 0.001, 0.01 or 0.1 μg. Amplitude and duration of SVP increases, frequency of burst within a contractile response of BS, as well as duration of the BS contractile response, were also determined. Bars and error bars represent the means±s.e.mean of n number of rats. BS, bulbospongiosus muscle; ICP, intracavernosal pressure; i.c.v., intracerebroventricular; MAP, mean arterial pressure; 7-OH-DPAT, 7-hydroxy-2-(di-N-propylamino) tetralin.