亚慢性染毒丙烯酰胺对雄性大鼠生殖及睾丸内分泌功能的影响

目的:探讨亚慢性丙烯酰胺染毒对雄性大鼠生殖及睾丸内分泌功能的影响。方法:选择SD雄性成年大鼠40只,随机分成4组,每组10只,灌胃给予丙烯酰胺,剂量分别为0、4、10、18mg/(kg.d),染毒9周。染毒结束后,测量大鼠后肢支撑力,精子存活率、精子畸形率、睾丸匀浆中碱性磷酸酶(ALP)和酸性磷酸酶(ACP)活性、血清和睾丸匀浆中T及E2浓度。建立睾丸Leydig细胞体外原代培养模型,丙烯酰胺体外染毒剂量分为0、0.1、0.75、4、8mmol/L,通过CCK-8法观察Leydig细胞活性。结果:随着染毒剂量的增加,后肢展开距离显著加宽(P<0.01)。精子存活率分别为(76.86±5.46)%、(65.43±5.16)%、(60.86±4.26)%和(46.86±2.73)%,各剂量组与对照组比较显著下降(P<0.01);畸形率分别为(39.00±10.95)%、(35.43±7.54)%、(45.71±13.28)%和(56.71±17.01)%,10、18mg/(kg.d)剂量组明显上升(P<0.05)。ACP活性为(82.93±11.05)、(73.52±8.77)、(77.67±3.04)、(68.56±3.09)U/gprot,呈下降趋势;ALP活性为(0.96±0.15)、(1.07±0.22)、(1.12±0.22)、(0.74±0.10)U/gprot,呈现先上升后下降的趋势。两者的活性在18mg/(kg.d)剂量组与对照组比较差异显著(P<0.05)。血清T浓度分别为(13.44±4.76)、(7.69±3.84)、(5.23±1.42)、(1.36±0.86)ng/ml,睾丸匀浆中T浓度分别为(4.95±1.64)、(3.01±0.76)、(2.44±0.91)、(0.85±0.49)ng/mgprot,两者各剂量组与对照组比较都显著下降(P<0.01)。各剂量组E2水平无明显差异。丙烯酰胺染毒24h后,培养细胞A值分别为0.82±0.06、0.56±0.07、0.44±0.06、0.26±0.03和0.45±0.21,0.1、0.75、4、8mmol/L剂量组Leydig细胞活性受到显著抑制(P<0.01)。结论:亚慢性丙烯酰胺染毒,影响精子正常发育,引起睾丸一些生化酶活性改变;大鼠后肢运动协调性明显受到影响;丙烯酰胺对Leydig细胞有直接损伤作用,影响其内分泌功能。

Subchronic Exposure to Acrylamide Affects Reproduction and Testis Endocrine Function of Rats

OBJECTIVE: To explore the effect of subchronic exposure to acrylamide on the reproduction and testis endocrine function of rats. METHODS: Forty healthy adult male SD rats were randomly divided into 4 groups of equal number, exposed to acrylamide at the dose of 0, 4, 10 and 18 mg/(kg x d) respectively for 9 weeks, and then subjected to the determination of the hindlimb landing foot splay, sperm vitality and morphology, the activities of acid phosphatase (ACP) and alkaline phosphatase (ALP) in the testis homogenate, and the levels of testosterone (T) and estradiol (E2) in the serum and testis homogenate. Based on the primary Leydig cell culture models exposed to acrylamide of 0, 0.1, 0.75, 4 and 8 mmol/L, the activity of Leydig cells was measured by the CCK-8 method. RESULTS: Following acrylamide exposure, the hindlimb landing foot splay increased markedly with dose increase (P < 0.01). The rates of sperm vitality were (6.86 +/- 5.46)%, (65.43 +/- 5.16)%, (60.86 +/- 4.26)% and (46.86 +/- 2.73)% in the exposed groups, significantly lower than in the control (P < 0.01); the rates of abnormal sperm were (39.00 +/- 10.95)%, (35.43 +/- 7.54)%, (45.71 +/- 13.28)% and (56.71 +/- 17.01)%, significantly increased in the 10 and 18 mg/(kg x d) groups (P < 0.05); ACP activities were (82.93 +/- 11.05), (73.52 +/- 8.77), (77.67 +/- 3.04) and (68.56 +/- 3.09) U/g prot, showing a decreasing tendency, while ALP activities were (0.96 +/- 0.15), (1.07 +/- 0.22), (1.12 +/- 0.22) and (0.74 +/- 0.10) U/g prot, displaying a tendency of first increasing and then decreasing. Both ACP and ALP activities were inhibited significantly in the 18 mg/(kg x d) group as compared with the control (P < 0.05). A marked reduction was noted in T levels in the serum, (13.44 +/- 4.76), (7.69 +/- 3.84), (5.23 +/- 1.42) and (1.36 +/- 0.86) ng/ml, as well as in the testis homogenate, (4.95 +/- 1.64), (3.01 +/- 0.76), (2.44 +/- 0.91) and (0.85 +/- 0.49) ng/mg prot, (P < 0.01), but no significant changes were observed in 17beta-E2 levels. After 24 hours exposure to acrylamide, the optical densities were 0.82 +/- 0.06, 0.56 +/- 0.07, 0.44 +/- 0.06, 0.26 +/- 0.03 and 0.45 +/- 0.21, showing an evident inhibition of the activity of Leydig cells at the dose of 0.1, 0.75, 4 and 8 mmol/L (P < 0.01). CONCLUSION: Subchronic exposure to acrylamide could affect the normal development of sperm, cause changes of the activity of some enzymes in the testis and significantly influence hindlimb motor coordination. Acrylamide directly damages Leydig cells and affects the endocrine function of the testis.