半胱胺盐酸盐和LHRH-A对黄鳍鲷生长激素分泌的影响

Effects of cysteamine hydrochloride and luteinizing hormone-releasing hormone analog on growth hormone secretion in Yellow-Fin Porgy

研究了生长抑素抑制剂半胱胺盐酸盐(CSH)和促黄体素释放激素类似物(LHRH A)对黄鳍鲷生长激素(GH)分泌的影响.黄鳍鲷垂体GH含量在单独注射不同剂量CSH(25,50,100μg/gb.w)后2h均显著提高,注射后24h恢复正常.黄鳍鲷血清中GH水平在注射CSH(100μg/gb.w)后2h和CSH(25,50μg/gb.w)后6h均明显提高.单独注射LHRH A(0.1μg/gb.w)后2h黄鳍鲷垂体GH含量和血清中GH水平均明显提高.注射CSH和LHRH A后6h垂体GH含量明显高于单独注射CSH或LHRH A,而血清GH水平在注射后12h明显高于单独注射CSH或LHRH A.结果表明CSH和LHRH A都能明显刺激黄鳍鲷垂体合成和释放GH,并且与CSH作用存在剂量依存关系,CSH和LHRH A联合注射比单独注射作用更明显,作用的时间更持久.

Effects of cysteamine hydrochloride (a somatostatin-inhibiting agent,CSH)and luteinizing hormone-releasing hormone analog on growth hormone secretion in Sparus latus were investigated by i.p. injection.The pituitary GH contents of Sparus latus were significantly increased 2 h post i.p. injection of CSH with doses of 25,50 and 100 μg/gb.w,and returned to control levels 24 h post injection. The serum GH levels of Sparus latus were significantly increased 2 h post injection of CSH with dose of 100 μg/gb.w,and 6 h post injection of CSH with doses of 25 and 50μg/gb.w; LHRH-A(0.1 μg/gb.w) significantly increased pituitary GH contents and serum GH levels 2 h post injection. Combining injection of LHRH-A and CSH significantly increased pituitary GH contents 6 h post injection as compared with CSH or LHRH-A alone,and the serum GH levels were significantly increased 12 h post injection as compared with CSH or LHRH-A alone.These results indicate that both CSH and LHRH-A could stimulate the synthesis and release of GH in Sparus latus, and the effects of CSH were dose dependent. The combined effects of CSH and LHRH-A were significantly higher than those of CSH or LHRH-A alone.