注射LHRH-A2对刀鲚的催产效果及其雌鱼血液生化指标的影响

Effects of LHRH-A_2 on induced spawning and responses of plasma biochemical indices of Coilia nasus

为了丰富刀鲚人工繁殖理论,探明LHRH-A2对刀鲚的催产效果及其雌鱼血液生化指标的影响,本研究以2冬龄人工养殖刀鲚为研究对象,通过注射LHRH-A2进行人工催产,并分析催产效果;同时应用放射性免疫、化学发光等方法,对人工催产过程中刀鲚雌鱼的血液生化指标进行了系统研究。结果显示,按照雌鱼30μg/kg、雄鱼减半的剂量注射LHRH-A2,刀鲚亲鱼死亡率为16.67%±3.34%;存活刀鲚亲鱼群体中,效应时间为21~24 h,催产率为83.33%±3.34%,受精率为75.06%±6.19%。注射催产素21 h内,血浆中17β-雌二醇（17β-estradiol,E2）、催乳素（prolactin）、甲状腺素（thyroxine,T4）、皮质醇（cortisol）、总蛋白（total protein,TP）、乳酸（lactate）在人工催产过程中表现出先上升后下降的规律;三碘甲腺原氨酸（three iodine thyroid,T3）、甘油三酯（triglyceride,TG）、Cl^–呈现持续下降趋势;谷丙转氨酶（alanine transaminase,ALT）、谷草转氨酶（aspartate transaminase,AST）、渗透压（osmotic pressure）、K^＋、Na^＋呈现持续上升的趋势。比较以上血浆指标在产卵组和未产卵组的实验结果,产卵组形成高皮质醇、TP、TG、渗透压、Na^＋、K^＋的血浆环境和低E2、催乳素、乳酸、T4、T3、Cl^-、ALT、AST的血浆环境,而未产卵组的这些指标与产卵组相反。结果表明,人工催产过程对肝脏、肾脏等正常功能造成了影响,从而抑制催产素LHRH-A2对卵子的正向调控作用。本研究初步揭示了人工催产应激对刀鲚雌鱼成功排卵的影响机制,为进一步优化刀鲚的规模化人工繁殖提供科学依据。

Effects of LHRH-A2 on induced spawning and plasma biochemical indices responses of Coilia nasus were studied in order to accomplish the artificial breeding protocol of this species. LHRH-A2 was used in those farm-raised, two–year–old（over 2 winters） C. nasus to analyze the function of induced spawning. Plasma biochemical indices of female C. nasus were determined using radioimmunoassay and chemiluminescent. Our results indicated that the average mortality rate of C. nasus was 16.67% ± 3.34% while female fish were injected a dose of 30 μg LHRH-A2 / kg body mass and male fish were injected with a dose of the half of the amount for female fish. The time of oxytocin induction in those survival fish ranged from 21 to 24 h, the average spawning rate was 83.33% ± 3.34% and the average fertilization rate was 75.06% ± 6.19%. The concentration of plasma 17β-estradiol（E2）, prolactin thyroxine（T4）, cortisol, total protein（TP） and lactic acid（lactate） increased initially and decreased thereafter while the contents of triiodothyronine（T3）, triglyceride（TG） and chloride ion（Cl^–） decreased constantly and the contents of alanine aminotransferase（ALT）, aspartate aminotransferase（AST）, osmotic pressure, potassium（K^＋） and sodium（Na^＋） increased continuously within 21 hours after the LHRH-A2 was used.The results also indicated that high cortisol, total protein, triglycerides, osmotic pressure, sodium ions, and potassium ions plasma environment, and a low 17β- estradiol, prolactin, lactic acid, thyroxine, triiodothyronine,chloride, alanine aminotransferase and aspartate aminotransferase plasma environment occurred in those spawned C. nasus. The opposite results occurred in those not spawned individuals. In summary, the normal functions of liver and kidney of C. nasus were influenced by the manipulation of inducing spawning, which resulted in the fact that the regulation of oxytocin LHRH-A2 to egg maturation was restricted. This preliminary study revealed the effect of LHRH-A2 on induced spawning and responses of plasma biochemical indices of C. nasus and provided the basis for the commercially artificial breeding of C. nasus.