摘要
为初步探讨急性低温胁迫下饲料中添加维生素C(VC)对珍珠龙胆石斑幼鱼HPI(下丘脑—垂体—肾间组织)轴及相关生理生化指标的调控作用,以初始体质量为(50.40±0.4)g的珍珠龙胆石斑鱼幼鱼为研究对象,配制VC含量分别为0、38、76、152、304 mg/kg的5组等氮等能的实验饲料,在养殖12周后进行急性低温(17°C)胁迫实验。结果显示,D38组增重率显著高于D152和D304组。不同水平VC对幼鱼生长无显著作用;不同水平VC对脑促肾上腺皮质激素释放因子(CRF)、血清中促肾上腺皮质激素(ACTH)、肾上腺素(EPI)和皮质醇(cortisol)浓度均无显著性变化;D0和D38组皮质醇浓度应激后均显著高于应激前。血清T3浓度随VC水平增加呈上升趋势;T4浓度不受VC水平的影响。各组T3、T4浓度在应激前后无显著差异;血清TSH浓度随VC水平增加呈先上升后下降的趋势;应激后各组TSH浓度均显著高于应激前。各组间肝脏GCK和HK浓度均不受VC水平影响,除D76组外,其他各组应激后GCK浓度均显著低于应激前;D76组HK浓度应激前后差异显著。急性低温胁迫后,各组肝脏PEPCK浓度均低于应激前,其中D38和D304组应激前后差异显著。研究表明,饲料中添加VC对急性低温胁迫下珍珠龙胆石斑鱼HPI轴相关激素酶活性可进行调控,并对鱼体甲状腺体具有一定保护作用,使胁迫后的鱼体达到生理稳态平衡,增强鱼体耐受性。
A trial was conducted to determine the effects of dietary Vitamin C levels on hypothalamic-pituitaryinterrenal axis and physiological indices of juvenile hybrid grouper（Epinephelus lanceolatu♂×Epinephelus fuscoguttatus♀） under acute low temperature stress.A basal diet was used as a control,and four other diets were prepared by supplementing 38,76,152,or 304 mg/kg vitamin C.Triplicate groups of fish（initial body weight,50g） were fed one of test diets at ratio of 1.5% or 2% body weight for 12 weeks at 27–28 °C.Uniform sizes of fish were selected for acute low temperature stress（17 °C） at the end of rearing management.Some biochemical indices in their serum and corticotrophin-releasing factor content of brain were examined over 2 hours.Results showed that： Weight gain of the fish fed with D38 group was significantly higher than that of D152 and D304 groups.We found no significant difference in corticotropin releasing factor content（CRF）,adrenocorticotropic hormone content（ACTH）,epinephrine content（EPI） or cortisol content in juvenile hybrid grouper,among all treatment groups.After acute low temperature stress,CRF content was increased by increasing dietary vitamin C levels.While ACTH and EPI content in serum showed a reverse trend,fish fed diets with vitamin C 304 mg/kg was significantly lower than control diet.Cortisol was reduced significantly in fish fed diets 76 mg/kg to 304mg/kg diets compared to control diet.Fish fed diets 152 mg/kg to 304 mg/kg dites T3 content were significantly higher than control diet.Whereas,after acute low temperature stress,fish fed diets 38 mg/kg to 304 mg/kg were significantly higher than control diet.There was no significant difference in T4 content in fish among different treatments.Fish fed diet 304 mg/kg diet showed significantly higher than other groups,whereas no difference was found among group D0 to D152.TSH content in D76 group exhibited obviously higher than D0,D38 or D304 groups.After acute low temperature stress,all diets containing vitamin C significantly elevated TSH content in serum.Dietary vitamin C levels had no strong effects on GCK and HK contents of liver.After acute low temperature stress,GCK content was negatively correlated with dietay vitamin C,and reached lowest value in 304mg/kg diet,and was significantly lower than other groups.HK content reached lowest value in 76 mg/kg diet,and was significantly lower than D0,D152,D304 groups.Significantly higher PEPCK value was found in fish fed 304mg/kg vitamin C compared to 0 mg/kg diet.After acute low temperature stress,PEPCK concentration was decreased significantly with increasing dietary vitamin C levels.All those data reveal new insights into the funtion of vitamin C that VC can modulate some biochemical indices of hypothalamic-pituitary-interrenal axis,protect and regulate the thyroid of fish,and maintain the dynamic balance of fish body under acute low temperature stress.
作者
郝甜甜
王丽丽
王际英
李宝山
马晶晶
王世信
张燕
谭青
张利民
HAO Tiantian WANG Lili WANG Jiying LI Baoshan MA Jingjing WANG Shixin ZHANG Yan TAN Qing ZHANG Limin(Key Laboratory of Marine Ecological Restoration, Shandong Marine Resources and Environment Research Institute, Yantai 264006, China Shengsuo Fishery Feed Research Centre of Shandong Province, Yantai 265500, China College of Fisheries and Life Sciences, Shanghai Ocean University, Shanghai 201306, China)
出处
《水产学报》
CAS
CSCD
北大核心
2017年第3期428-437,共10页
Journal of Fisheries of China
基金
国家海洋生物产业水生动物营养与饲料研发创新示范平台(201601003)
山东省科技发展计划(2014GHY115006)
山东省自然科学基金青年基金(ZR2015CQ023)
山东省优秀中青年科学家奖励基金(BS2013HZ018)~~
关键词
珍珠龙胆石斑鱼
维生素C
急性低温胁迫
HPI轴
hybrid grouper
vitamin C
acute low temperature stress
hypothalamic-pituitary-interrenal axis
