热应激对公兔精液品质、睾丸组织形态及抗氧化指标的影响

为探讨热应激对公兔精液品质、睾丸组织形态及抗氧化物活性的影响，分别测定高温（31±2）℃与适温（18＋2）℃条件下公兔采精量及精子活力、密度、畸形率，并取睾丸组织制作石蜡切片进行组织形态观察及制成组织匀浆测定丙二醛（MDA）、超氧化物歧化酶（SOD）、谷胱甘肽过氧化物酶（GsH—Px）、总抗氧化能力（T—AOC）。结果表明：热应激致使公兔采精量、精子活力和密度显著下降（P〈0．05），睾丸组织细胞严重损伤、数量减少，睾丸组织中MDA含量显著增加（P〈0．05），而SOD、GSH—Px活性和T—AOC显著降低（P〈0．05）。可见，热应激导致公兔精液品质下降，可能与睾丸组织中抗氧化酶活性降低、自由基生成过多、睾丸组织细胞受损有关。

Effect of heat stress on sperm quality,testis morphology and antioxidant indices in male rabbits

The present experiment was conducted to study the effects of heat stress on sperm quality, testis morphology and antioxidant activity in male rabbits. Twelve adult New Zealand rabbits with good body condition and equal body weight were selected and averagely divided into two groups, viz., control group of optimal temperature （18±2）℃ without heat stress and treated group of high-temperature （31±2）℃ heat stress. After feeding two months, the semen of male rabbit was collected once at every third day for 5 times in all to determine the semen volume and the mobility, density, and deformity rate of sperm. The tissue morphology of testis was observed by paraffin section, and the malondialdehyde （MDA）, superoxide dismutase （SOD）, glutathione peroxidase （GSH-PX）, total antioxidant capacity （T-AOC） in testis tissue were determined. The results showed that the semen amount and mobility and density of sperm of rabbit were decreased significantly when treated with heat stress （P〈0.05）. The testicular tissue cells were found to be seriously damaged with decreasing quantity. The MDA contents of testicular tissue increased significantly （P〈0.05）, while the SOD, GSH-PX activity and T-AOC contents decreased significantly（P〈0.05）. These results indicated that the sperm quality of rabbits treated with heat stress was declined, which may be related to the decrease in antioxidant enzyme activity of testis resulting in excessive free radical production and damaged testicular tissue cells.