急性温度胁迫对妊娠期许氏平鲉血清皮质醇和血液生理指标的影响

Effect of acute temperature stress on serum cortisol and hematological physiology of gestated Sebastes schlegelii

为探究鱼类对温度突变水体的适应性和恢复性,将妊娠期许氏平鲉由正常水温(16℃)直接转入高温(25℃)和低温(7℃)水体,急性胁迫2 h后再恢复至16℃,检测恢复期第0、6、12、24、48和72 h时妊娠期许氏平鲉血清皮质醇(COR)和血液生理指标的变化情况。结果显示,25℃急性胁迫导致2尾鱼发生产仔行为;25℃和7℃急性胁迫后的恢复过程中,血清(COR)、血糖(GLU)、球蛋白(GLB)、丙氨酸氨基转移酶(GPT)、天门冬氨酸氨基转移酶(GOT)和白细胞(WBC)水平均显著升高,总蛋白(TP)、白蛋白(ALB)、总胆固醇(TC)及甘油三酯(TG)水平显著降低,血清钙(Ca^(2+))、镁(Mg^(2+))和无机磷(P)水平无显著变化;红细胞(RBC)和血红蛋白(HGB)水平在25℃胁迫后明显上升,而在7℃胁迫后显著下降(P<0.05)。与急性低温胁迫相比,急性高温胁迫对妊娠期许氏平鲉机体生理情况的影响更显著。除COR和无机离子外,多个生理指标在72 h后仍未恢复至正常水平。研究表明,急性温度胁迫导致妊娠期许氏平鲉生理状况和代谢水平受到显著影响,甚至发生提前产仔行为。在养殖生产中,对于进入生殖期的雌鱼,应密切监测水温变化,尤其是水温的上升,以减少温度应激导致的妊娠损伤。

To explore the adaptability and restoring ability in w ater w ith mutant temperature,gestated Sebastes schlegelii w ere moved from normal temperature（ 16 ℃） to high（ 25 ℃） or low（ 7 ℃）temperature w ater,being exposed for 2 h,and subsequently transferred to original seaw ater of 16 ℃. Samples w ere collected at 0,6,12,24,48 and 72 h during recovery to detect changes of serum cortisol（ COR） and hematological and physiological parameters of gestated Sebastes schlegelii. The data show ed that acute thermal stress led to parturition behavior of tw o fish; It w as noted that COR,glucose（ GLU）,globulin（ GLB）,glutamic-pyruvic transaminase（ GPT）,glutamic-oxaloacetic transaminase（ GOT） and white blood cell（ WBC） levels in serum increased significantly（ P〈0. 05） w hereas concentrations of total protein（ TP）,albumin（ ALB）,total cholesterol（ TC） and triglyceride（ TG） became low er obviously during recovery process after acute stress of 25 ℃ and 7 ℃（ P〈0. 05）. Besides,there w as no difference in Ca^（2＋）,Mg^（2＋） and P contents. Interestingly,red blood cell（ RBC） and hemoglobin（ HGB） levels arose remarkably after acute heat stress（ P〈0. 05） w hile those w ere detected dow n-regulated by acute chilling stress（ P〈0. 05）. It w as observed that thermal stress had a sharper effect on physiological status compared w ith acute chilling stress.M oreover,most indexes,except for COR and inorganic ions,did not restore to normal level after 72 hours.Our results suggest that acute temperature stress results in distinct impact on physiological function and metabolic levels of gestated Sebastes schlegelii,and even parturition behavior in advance. It is of high importance to monitor closely w ater temperature fluctuation,especially elevation,as for female fish entering the reproductive phase,in order to decrease injury induced by temperature stress during pregnancy.