[Qiaoshao Prescription improves premature ejaculation in male rats by increasing the content of 5-hydroxytryptamine]

To observe the intervention effect of Qiaoshao Prescription (QSP) on premature ejaculation (PE) induced by 8-OH-DPAT in male rats and explore its possible action mechanism.

Seventy-two male Wistar rats were equally randomized into six groups, blank control, PE model control, low-, medium- and high-dose QSP, and dapoxetine. The PE model was established by injection of 8-OH-DPAT into the subarachnoid space of the lumbosacral spinal cord. Four weeks after modeling, the rats in the blank control and PE model control groups with gavaged with normal saline at 10 ml/kg/d, those in the low-, medium- and high-dose QSP groups with QSP at 5, 10 and 20 g/kg/d respectively once a day, and those in the dapoxetine group with dapoxetine hydrochloride at 300 mg/kg at 3 hours before mating. Forty-five female Wistar rats were injected subcutaneously with 20 μg estradiol benzoate after removal of bilateral ovaries to induce estrous estrus. Two and 4 weeks later, the male rats were mated with the female ones for 30 minutes per time and meanwhile observed for the mating behavior of the males, including mounting latency (ML), intromission latency (IL), ejaculation latency (EL), mounting frequency (MF), intromission frequency (IF), and ejaculation frequency (EF). After the 4th week of mating, the hypothalamus of the animals was isolated and weighed, and the content of 5-hydroxytryptamine (5-HT) was measured.

Compared with the blank control group, the PE model controls showed significantly decreased content of 5-HT in the hypothalamus(1 257.1 vs 923.4 ng/g, P<0.05), ML (［11.22 ± 3.60］ vs ［8.69 ± 2.48］ s, P<0.05), IL (［22.33 ± 2.45］ vs ［12.08±1.39］ s, P<0.05), MF (［13.28 ± 3.24］ vs ［7.53 ± 1.84］ times, P<0.05), and EL (［712.35 ± 36.77］ vs ［502.35 ± 46.72］ s, P<0.05). In comparison with the PE model controls, the rats of the QSP and dapoxetine groups exhibited remarkably increased content of 5-HT (P<0.05) and prolonged EL (P<0.05).

Qiaoshao Prescription can prolong EL in PE rats, which might be associated with the increased content of 5-HT in the hypothalamus. Further studies, however, are needed on its underlying mechanisms.