ObjectiveTo investigate the feasibility and practicability of establishing an animal model of primary premature ejaculation using the ejaculation distribution theory.

METHODSWe induced behavioral estrus in 32 ovariectomized female SD rats by subcutaneous injection of 20 μg estradiol benzoate at 48 hours and 500 μg progesterone at 4 hours before mating them with 49 male rats once a week for six times. During the last three opulations, we observed the male animals for mounting latency (ML), intromission latency (IL), ejaculation latency (EL), postejaculation interval (PEI), mounting frequency (MF), intromission frequency (IF), intromission rate (IR), and ejaculation frequency (EF).

RESULTSFinally, 22 of the male rats were included in this study. The mean EF>33 was deemed rapid ejaculation,EF<1 sluggish ejaculation, and EF 1.5－2.5 normal ejaculation. The EL was significantly shorter in the rapid ejaculation group than in the sluggish and normal ejaculation groups. The IF was the lowest in those with rapid ejaculation. No statistically significant differences were observed in the ML among the three groups of rats.

CONCLUSIONSBased on the mean ejaculation frequency, the male rats with rapid ejaculation were easily screened, and this animal model may play an important role in exploring the mechanisms of primary premature ejaculation.