摘要
在室内可控条件下,对尼罗罗非鱼[初始体质量（62.50±3.44）g]进行饥饿28d和随后再投喂21d的处理,于饥饿第0、7、14、21、28天和再投喂第14、21天进行采样分析,研究饥饿和再投喂期间尼罗罗非鱼生长、血清生化指标和肝胰脏生长激素（GH）、类胰岛素生长因子-Ⅰ（IGF-Ⅰ）和胰岛素（IN）mRNA表达丰度的变化。结果显示,与饥饿第0天相比,饥饿超过7d鱼体体质量显著降低（P〈0.05）,再投喂21d显著增加（P〈0.05）;肝体比随饥饿时间延长显著降低（P〈0.05）,恢复投喂后较饥饿时升高,但显著低于饥饿前水平（P〈0.05）。在血清指标上,甘油三酯、血糖、碱性磷酸酶、谷草转氨酶和谷丙转氨酶均随饥饿时间延长而逐渐降低,恢复投喂后均有不同程度提高,但转氨酶活性显著低于饥饿前水平（P〈0.05）;饥饿和再投喂对血清总胆固醇、高密度脂蛋白胆固醇和低密度脂蛋白胆固醇无显著影响（P〉0.05）。在激素方面,与饥饿第0天相比,饥饿使血清GH含量及其肝胰脏mRNA表达丰度显著升高,血清IGF-Ⅰ及其肝胰脏mRNA表达丰度降低,恢复投喂后两者均显著升高（P〈0.05）;INmRNA表达丰度在饥饿7~21d显著升高（P〈0.05）,饥饿第28天时无显著差异（P〉0.05）,再投喂后显著降低（P〈0.05）。
Studies were conducted to reveal the changes in growth, serum biochemical indices and growth hormone （GH）, insulin-like growth factor Ⅰ（IGF-Ⅰ） and insulin （IN） mRNA expression abundance of Nile tilapia （Oreochromis niloticus） during fasting and re-feeding. Nile tilapia with initial body weight （62.50 ± 3.44） g were starved for 28 d and then fed for 21 d under controllable indoor environment. Fish were sam-pled at 0, 7, 14, 21 and 28 d during fasting and at 14 and 21 d during re-feeding, respectively. The results indicated that the body weight was significantly decreased when fasting over 7 d （P0.05）, and signifi-cantly increased when re-feeding for 21 d （P0.05）. The hepatosomatic index was significantly decreased throughout the experiment （P0.05）. Significant reduction was observed in the content of triglyceride and glucose, and in the activities of alkaline phosphatase, glutamic oxaloacetic transaminase and glutamic py-ruvic transaminase after fasting （P0.05）; After re-feeding, the value of these indices increased in varying degrees, but the activity of transaminase was significantly lower than initial value（P0.05）. There was no change in total cholesterol, high density lipoprotein cholesterol or low density lipoprotein cholesterol dur-ing the experiment （P0.05）. Serum GH and liver GH mRNA levels showed significantly up-regulation, whereas significant down-regulation was observed in serum IGF-Ⅰ and liver IGF-Ⅰ mRNA levels after fasting, and after re-feeding both of them increased （P0.05）. IN mRNA level was significantly increased during fasting for 7-21 d （P0.05）, but its level was not obviously changed when fasting for 28 d （P0.05）, then was significantly decreased after re-feeding （P0.05）. The present study revealed that fasting could restrain the growth of O. niloticus, promote serum triglyceride and glucose breakdown, and decrease the activity of transaminase. Serum GH/IGF-Ⅰ and liver GH/IGF-Ⅰ mRNA expression abundance displayed synchronous changes and the liver IN mRNA expression abundance was significantly increased when fasting for 7-21 d and then decreased to normal level when fasting for 28 d. It suggests that the level of GH/IGF-Ⅰ gene transcription of O. niloticus may be the most important factor in determining the levels of hormone in serum, while down-regulation of serum insulin may be due to its release reduction in islet when fasting.
出处
《水产学报》
CAS
CSCD
北大核心
2012年第6期900-907,共8页
Journal of Fisheries of China
基金
国家罗非鱼产业技术体系(CARS-49)
农业部2010年公益性行业科研专项经费(201003020)
中央级公益性科研院所基本科研业务费专项资金(2011JBFA21)
