LHRH-A和hCG对南方鲶血清促性腺激素水平的影响

运用放射免疫分析法测定了促黄体释放激素类似物 (LHRH A)和人绒毛膜促性腺激素(hCG)对南方鲶血清促性腺激素 (GTH)水平的影响 ,结果表明 :LHRH A和hCG都能提高南方鲶一龄幼鱼血清GTH水平 ,hCG与LHRH A结合注射后血清GTH水平显著高于单独注射hCG或LHRH A后的血清GTH水平。LHRH A和hCG结合注射可诱导性成熟南方鲶排卵 ,同时排卵过程中伴随着血清GTH水平的急剧上升 ,在排卵后迅速下降 ;注射同样剂量的药物而未排卵的血清GTH水平虽有升高 ,但升高的幅度不及排卵鱼。这种血清GTH水平的急剧增高对诱导南方鲶卵母细胞最后成熟和排卵具有重要作用。

Effect on the Level of Serum Gonadotropin after Injection of LHRH-A and hCG in the Southern Catfish(Silurus meridionalis Chen)

The levels of serum gonadotropin(GTH) after injection of LHRH A and hCG were determined by using ridioimmunoassay in the southern catfish ( Silurus meridionalis Chen). The serum GTH levels increased after injection of LHRH A or hCG in one year old southern catfishes. Much higher GTH levels were detected after a combined injection of hCG and LHRH A than that of hCG or LHRH A separately. Combined injection of LHRH A and hCG can be used to induce ovulation of mature southern catfish. There also was a peak of serum GTH level during the ovulation, but it decreased quickly after ovulation. A peak of serum GTH level also was found in the unovulated fish after injection of the same dose of LHRH A and hCG. However, the peak was lower than that of the ovulated fish. The results suggested that the GTH surge increasing was important to induce the final maturation of oocyte and ovulation in the southern catfish.