镉对鲤血清促性腺激素和生长激素的影响

EFFECTS OF CADMIUM ON SERUM GONADOTROPIN AND GROWTH HORMONE IN COMMON CARP(CYPRINUS CARPIO L.)

采用ＣｄＣｌ２浸没法处理鲤，研究镉对鲤血清促性腺激素（ＧｔＨ）和生长激素（ＧＨ）水平的影响。结果表明：较高浓度镉（ＣｄＣｌ２９ｍｇ／Ｌ）处理引起血清ＧｔＨ水平降低，ＧＨ水平升高；提高水中钙浓度，能使由镉引起的ＧｔＨ水平的降低恢复到正常水平，并对镉引起的ＧＨ水平升高起延迟作用；镉处理使鲤对ＬＨＲＨ－Ａ刺激ＧｔＨ分泌的反应性下降，提高水中钙浓度也不能恢复正常。实验结果提示：镉引起的ＧｔＨ和ＧＨ的变化可能主要是镉干扰了钙的生理作用。

Effects of Cd2+ on serum gonadotropin (GtH) and growth hormone (GH) levels of common carp (Cyprinus carpio L. ) by immersion treatment with CdCl2 were studied. Being treated with the high concentration of CdCl2 (9mg/L) for 12 days, the GtH level was significantly lower than that of the control (1. 82±0. 58 VS 3. 50±0. 78ng/ml) (P<0. 01). Being exposed to CdCl2 (9mg/L) for 8 or 12 days, the GH levels were significantly higher than that of the corresponding controls (170. 4±54. 3 VS 90. 2±14. 6 ng/ml or 147. 1±47. 5 VS 86. 4±11. 4 ng/ml) (P<0. 01). Being treated with cadmium plus calcium (CdCL29mg/L+CaCL2111mg/L, Mol. Cd2+: Ca=1: 20) for 8 days, the GH level of the fish was not significantly different than that of the control (95. 3±5. 3 VS 90. 2±14.6ng/ml) (P>0. 05) , but for 12 days, the GH level was significantly higher than that of the control (135. 4±30. 0 VS 86. 4±11. 4ng/ml) (P< 0. 01), and the GtH level was not significantly different than that of the control (4. 05±0. 71 VS 3. 50±0. 78 ng/ml) (P>0. 05). Therefore, the lowing of GtH level caused by the CdCl2 can be restored, the raising process of GH level caused by the CdCl2 can be delayed by increasing water Ca2+ concentration. Being treated with the low concentration (0. 3mg/L), the high concentration (9mg/L)of CdCl2 and CdCl2 (9mg/L) plus CaCl2 (111mg/L) for 14 days, the LHRH-A-stimulated GtH secreation were significantly lower than that of control (P<0. 05) in common carp. The results suggest that toxic effects of cadmium on GtH and GH secreation might be Cd2+ disturbed Ca2+ action.