性腺发育及年龄对养殖中华鲟抗氧化力的影响

以养殖的子一代（n=21）中华鲟为对象,研究了性腺发育及年龄对其抗氧化力的影响。结果表明：（1）1998年生子一代雌性(未达性成熟，性腺处于慢速发育阶段)和雄性(接近性成熟，性腺处于开始快速发育阶段)的睾酮和雌二醇/睾酮差异显著，雌性血清丙二醛水平显著低于雄性，而超氧化物歧化酶和谷胱甘肽过氧化酶的活力及超氧化物歧化酶/丙二醛值虽高于雄性，但二者间不存在显著性差异，雌性和雄性的丙二醛与超氧化物歧化酶/丙二醛之间相关性极显著（r=-0915，-0818，P＜001);（2）雌二醇/睾酮值与丙二醛显著负相关，与超氧化物歧化酶/丙二醛显著正相关（r=-0635，r=0709，P＜005），与超氧化物歧化酶、谷胱甘肽过氧化酶无显著相关性；（3）4个年龄组（4、8、11、12龄,未达性成熟）的超氧化物歧化酶和丙二醛无显著性差异，12龄组的谷胱甘肽过氧化酶显著低于其余3组，而超氧化物歧化酶/丙二醛显著高于其余3组，谷胱甘肽过氧化酶和丙二醛与年龄呈负相关（r=-0547,P＜001；r=-0519,P＜005），超氧化物歧化酶/丙二醛与年龄呈正相关（r=0569,P＜001）。这表明进入性腺快速发育阶段的雄性氧化应激水平明显高于处于性腺慢速发育阶段的同龄雌性；随着年龄增长，未达性成熟中华鲟的抗氧化力水平逐渐增强；使用以上指标作为亚健康群体的筛选指标和氧化应激的生物标志物时，应充分考虑监测群体性腺发育和年龄因素，以使参考指标更准确

EFFECTS OF GONAD DEVELOPMENT AND AGE ON THE ANTIOXIDANT DEFENSES OF CHINESE STURGEON(Acipenser sinnesis)

The effects of gonad development and age on the serum antioxidant enzyme activities of captive F1 Chinese sturgeon,Acipenser sinensis,were studied.When females in the period of slow gonadal development and males in the period of fast gonadal development were compared,testosterone (T) and the ratio of estrogen (E2)〖DK〗∶testosterone levels were significantly different.Compared to males,the females had a significantly lower malondialdehyde (MDA) level (P<005),but higher activity levels of superoxide dismutase (SOD),glutathione peroxidase (GPX) and SOD/MDA,although these differences were not significant (P＞0.05).For MDA and SOD/MDA in the serum of males and females,high values were found for the correlation coefficients (r=-0915,r=-0818,P<001,respectively).Serum E2/T levels correlated with MDA,SOD/MDA (r=-0635,r=0709,P<005,respectively),while not correlated with SOD or GPX.No significant differences in the activity of serum SOD or MDA were observed in all four different ages(4,8,11 and 12 years old) during the period of slow gonad development.The lowest level of GPX activity was found in the 12-year old age group (P<005),whereas the highest level of the SOD/MDA ratio was observed in this group (P<005).The correlation between the age and the activity of GPX,MDA was negative (r=-0547,P<001,r=-0519,P<005,respectively),while the correlation between the age and the level of the SOD/MDA ratio was positive (r=0569,P<001).These results suggest that the level of oxidant stress in male sturgeons during the period of fast gonad development is higher than those of females during the period of slow gonad development.The antioxidant defense mechanisms of sturgeons gradually increase with increasing age.Therefore,the gonad development and age of the fish should be considered when indexes of antioxidant enzyme activities are used to assess status of fish health.Understanding the biological signaling that underlies these changes will make the use of these parameters even more accurate.