Objective: To explore the feasibility and practicability of establishing a rat model of premature ejaculation (PE) by injection of 8-OH-DPAT into the subarachnoid space of the lumbosacral spinal cord segments.
Methods: Twenty-four male Wistar rats were equally randomized into a PE model and a blank control group. The PE model was established by injection of 8-OH-DPAT in 10 ml normal saline at 0.8 mg per kg of the body weight per day into the subarachnoid space of the lumbosacral spinal cord segments and the control rats were injected with the same volume of normal saline only, both for 4 weeks. Another 24 female Wistar rats were injected subcutaneously with benzoic acid estradiol at 20 μg to induce estrus at 36 hours before mated with the male animals. At 2 and 4 weeks, the male rats were mated with the female ones for 30 minutes each time and meanwhile observed for their mating behavior indicators, such as mount latency, intromission latency, ejaculation latency, mount frequency, intromission frequency, and ejaculation frequency.
Results: Compared with the controls, the PE model rats showed a significantly lower ejaculation latency (［712.35 ± 36.77］ vs ［502.35 ± 46.72］ s, P<0.05), mount latency (［11.22 ± 3.60］ vs ［8.69 ± 2.48］ s, P<0.05), mount frequency (13.28 ± 0.24 vs 7.53 ± 1.84, P<0.05), and intromission latency (［22.33 ± 2.45］ vs ［12.08 ± 1.39］ s, P<0.05), but a remarkably higher ejaculation frequency (2.01 ± 0.48 vs 4.26 ± 0.89, P<0.05). No statistically significant difference was observed between the control and model animals in the intromission frequency (7.49 ± 2.21 vs 6.45 ± 1.89, P>0.05).
Conclusions: A rat model of premature ejaculation was successfully established by injection of 8-OH-DPAT into the subarachnoid space of the lumbosacral spinal cord segments, which is of great significance for further study of the mechanism of premature ejaculation.
目的: 探讨运用8-羟基-2-(二丙基氨基)四氢萘氢溴酸盐（8-OH-DPAT）腰骶脊髓节段蛛网膜下腔囊内注射建立早泄大鼠模型的可行性及实用性。方法: 选择雄性Wistar大鼠24只，按照1∶1随机分为2组，A组:空白对照组（等量生理盐水）；B组:模型组［将8-OH-DPAT 溶于10 ml生理盐水中，按0.8 mg/(kg·d)，进行腰骶脊髓节段蛛网膜下腔囊内注射，持续4周］。雌性Wistar大鼠24只，摘除卵巢后，于合笼前36 h皮下注射苯甲酸雌二醇20 μg以诱导雌性大鼠发情。在第2周和第 4周时，将雄性大鼠和激素诱导的雌性大鼠合笼，进行交配实验，每次30 min。观察和记录雄性大鼠的交配行为，包括骑跨潜伏期、插入潜伏期、射精潜伏期、骑跨次数、插入次数、射精次数。结果： 药物干预后，B组的射精潜伏期［（502.35±46.72） s］明显低于A组［（712.35±36.77） s］，骑跨潜伏期［（8.69±2.48） s］明显低于A组［（11.22±3.60） s］，骑跨次数［（7.53±1.84）次］明显低于A组［（13.28±0.24）次］，插入潜伏期［（12.08±1.39） s］明显低于A组［（22.33±2.45） s］，射精次数［（4.26±0.89）次］明显高于A组［（2.01±0.48）次］，差异均有统计学意义(P均<0.05）；插入次数［（6.45±1.89）次］与A组［（7.49±2.21）次］无明显差异(P>0.05)。结论： 用8-OH-DPAT腰骶脊髓节段蛛网膜下腔囊内注射，可以较好的建立早泄大鼠模型，该模型对深入研究早泄机制有十分重要的意义。.
Keywords: 8-OH-DPAT; animal model; rat; premature ejaculation.