饥饿胁迫对瓦氏黄颡鱼脂肪代谢的影响

THE EFFECT OF STARVATION ON LIPID METABOLISM OF DARKBARBEL CATFISH, PELTEOBAGRUS VACHELLI

在水温(25±2)℃条件下,对初始体重为(23.65±2.82)g的瓦氏黄颡鱼进行30d饥饿处理,于饥饿第0、第7、第15和第30天取样,分析了饥饿胁迫对瓦氏黄颡鱼的生长、体成分、脂肪酸组成和脂肪代谢相关基因表达的影响。结果表明:饥饿胁迫显著降低了瓦氏黄颡鱼肥满度、脂体比及肝体指数(P<0.05)。肌肉脂肪含量也随着饥饿时间的延长而下降(P>0.05)。肝脏中的饱和脂肪酸和肌肉中的单不饱和脂肪酸显著下降,而肝脏中多不饱和脂肪酸和单不饱和脂肪酸及肌肉中的多不饱和脂肪酸显著上升(P<0.05)。此外,肌肉中的n-6和n-3及肝脏中的n-6多不饱和脂肪酸显著上升,而肝脏中的n-3多不饱和脂肪酸显著下降(P<0.05),表明瓦氏黄颡鱼饥饿期间主要消耗饱和脂肪酸及单不饱和脂肪酸供能,保留多不饱和脂肪酸。饥饿胁迫15—30d,瓦氏黄颡鱼肝脏脂蛋白酯酶、肝酯酶及肉碱酰基转运酶m RNA表达显著高于对照组(0d)(P<0.05),而脂肪酸结合蛋白及脂肪酸合成酶m RNA的表达显著低于对照组(P<0.05),表明饥饿胁迫可能会促进肝脏脂肪分解供能,降低脂肪的生物合成。

In this study, we investigated how starvation could affect the lipid metabolism of darkbarbel catfish(Pelteobagrus vachelli). Fish with initial weight of(23.65±2.82) g were selected for a 30-day fasting treatment and were sampled on the 0, 7th, 15 th and 30 th day during starvation. The results showed that starvation caused a significant decrease in the hepatosomatic index and intraperitoneal fat ratio(P<0.05). The fat and protein content in muscles also dropped but insignificantly(P>0.05). Plus, we observed lower saturation fatty acid(SFA) in the liver and mono unsaturation fatty acid(MUFA) in muscles during the starvation(P<0.05). In the contrast, poly unsaturation fatty acid(PUFA) and MUFA in the liver and PUFA in muscles were significantly elevated(P<0.05). Moreover, n-6 and n-3 PUFA in muscles and n-6 PUFA in the liver obviously increased too, whereas, n-3 PUFA in liver dropped(P<0.05). These results suggested that during starvation, darkbarbel catfish could metabolise SFA and MUFA for energy supply but reserve PUFA. The real-time PCR results showed that compared to 0d fasting, 15 d to 30 d fasting might enhance the m RNA expression of LPL, HL and CAT in the liver(P<0.05) and suppress the expression of FAS and L-FABP in the liver(P<0.05). Our results suggested that starvation may induce lipoclasis and reduce the biosynthesis of lipid in the liver.