GnRH二聚体和GnRH并列二聚体合成肽疫苗对大鼠的免疫去势效果

Efficacy of Immunocastration Vaccines Composed of GnRH-dimer or GnRH-tandem-dimer Peptides in Rats

为了比较GnRH二聚体和GnRH并列二聚体单次和两次免疫对雄性大鼠的免疫去势效果。将上述两种GnRH疫苗,分组免疫SD大鼠,免疫后每两周检测大鼠血清中的GnRH抗体滴度和血清睾酮水平、睾丸重量和组织结构变化。结果显示,两次免疫试验组的抗体滴度显著高于单次免疫试验组的抗体滴度(P<0.05);GnRH二聚体抗原免疫效果优于GnRH并列二聚体抗原的免疫效果,且差异极显著(P<0.01)。免疫组大鼠血清睾酮水平及睾丸重量均极显著低于空白对照组(P<0.01)。免疫去势效果显著的大鼠只数统计显示,GnRH二聚体(5/6)和GnRH并列二聚体(4/6)两次免疫均多于单次免疫(4/6和3/6)。同时,组织学观察结果可见,免疫组大鼠睾丸组织结构萎缩,曲精小管管径变窄,内部精母细胞脱落,精子变少或者没有。表明GnRH二聚体疫苗与GnRH并列二聚体疫苗均能达到去势效果,前者优于后者,两次免疫优于一次免疫。

This study was performed to evaluate the cines in male SD rats by single and double immunization. castration efficacies of GnRH-dimer and GnRH-tandem-dimer peptide vac- GnRH-dimer and GnRH-tandem-dimer peptides were prepared as emulsion vaccines. The testosterone concentration and GnRH antibodies in the sera, weight of testes and histological structural changes were observed. The results showed that in immunization groups, GnRH-dimer and GnRH-tandem-dimer peptide vaccines both induced higher titer anti-GnRH antibodies （P 〈 0.01 ）. The antibody titers of double immunization group were significautly higher than those of single immunization group （ P 〈 0. 05 ）. In the GnRH-dimer immunized group, the titers of anti-GnRH antibodies were higher than those immunized with GnRH-tandem-dimer vaccine （ P 〈 0. 05 ）. Serum testosterone and testis weights indicated that the concentrations in all immunization groups were lower than those of control group （ P 〈 0.01 ）. Significantly, in the groups which were immunized twice, the serum testosterone of 5 rats in GnRH-dimer group and 4 rats in GnRH-tandem-dimer group was even decreased to be undetectable. However, the corresponding number was 4 and 3 when the rats were immunized once with the respective vaccine. Meanwhile, the testes were observed atrophy in tissue structure as well as a narrowing of the internal diameter of seminiferous tubule, shedding Qf internal spermatocyte and less or even no sperm, GnRH dimer vaccine and GnRH-tandem-dimer vaccine respectively have significant effect of immunocastration in rats. The effect of double immunization is better, and GnRH-dimer peptide is more promising than GnRH-tandem-dimer peptide as a vaccine candidate.