日本鳗鲡雌鳗卵巢发育期间肌肉脂肪酸的组成及消耗

研究采用3种不同的处理方式(I&GD、I&nGD和A&nGD)对雌鳗处理后,进行了生物学相关参数、肌肉脂肪酸组成和含量变化测定分析.研究结果表明,日本鳗鲡在性腺发育期间,体重一直呈一个下降的趋势,直到产卵前,才显著高于野生海鳗.该现象被称为水合反应.实验结束时,3个实验组的脂肪总量均有不同程度的下降,其中,I&GD组下降最多,占总脂肪的66.55%;其次是A&nGD组,占总脂肪的43.76%;下降最少的是I&nGD组,占总脂肪的34.68%.研究对日本鳗鲡的肌肉共测出了17种脂肪酸,SFA 7种、MUFA 2种、PUFA 8种.其中,MUFA虽然只有2种,但在脂肪酸总量中占的百分比却较高达38.02%,而且它们的消耗与性腺发育和基础代谢有关,与雌鳗的游泳耗能无关.在8种PUFA中,AA的变化很特殊.实验期间,它在日本鳗鲡肌肉内是一个积累和消耗的动态过程.而且,积累程度与雌鳗的游动有关,游动越多,积累越多.EPA虽然能被检出,但量很低,而且各组间的变化无明显规律.DHA在日本鳗鲡肌肉中的含量达到123.91 mg/g干肌肉,占总脂肪的32.52%.卵巢发育所消耗的量也很多,I&GD组在卵巢发育结束后,下降到10.59 mg/g十肌肉.相关性分析发现.虽然总脂肪酸、PUFA、DHA和EPA与GSI间均存在一定程度的负相关性,但关系最密切的是DHA,其r=-0.952(P<0.01,n=5),关系最小的是EPA,其r=-0.882(P<0.05,n=5).因此分析认为DHA是日本鳗鲡性腺发育所需的最主要的一种脂肪酸.对能量分布进行综合分析后认为,日本鳗鲡在人工诱导性腺发育期间,基础代谢所需的脂肪量(LBM)占总脂肪量的34.68%,性腺发育所需脂肪量(LGD)占总脂肪量的32.49%,运动耗能所需脂肪量(LM)占总脂肪量的9.79%.因此认为,日本鳗鲡在不摄食的情况下,肌肉中的脂肪不仅能提供性腺发育所需的营养物质,而且还能满足洄游2000海里到达产卵场所需的能量.

Composition and metabolizing of lipids and fatty acids in muscle of female Anguilla japonica during the period of artificial inducing ovarian maturation

This experiment adopted three methods (I&GD,I&nGD and A&nGD) to treat the females of Japanese eel. After being treated, the biological data of female, which related with their gonadal development, were investigated and the changes of fatty acids in their muscle were measured by gas liquid chromatography. The purpose of this study is try to discuss the lipid consumptions for gonadal development, basal metabolization and migration fuel during spawning migration, as well as the relationship between gonadal development and fatty acids consumption in the period of artificial inducing gonadal maturation, in order to provide referenced foundation for future studies on artificial propagation in Japanese eel. The results indicated that the body weight of females came through a course of gradual downward trend before the 10 injection and rapid rise at the beginning of spawning, which was called hydration, as well as the lipids of muscle tissue were necessary not only for gonadal development, but also for basal metabolization and migration energies in Japanese eels during the spawning migration. In this study, 17 fatty acids were detected in muscle tissues of females, including 7 SFA, 2 MUFA and 8 PUFA. Among them, there were only two kinds of MUFA, but their total levels were higher and reached at 38.02 percent of total lipids. Their consumptions were related with gonadal development and basal metabolization, unrelated to the energy for swimming. Among 8 PUFA, the changes of AA in three treated groups were very special. It was a dynamic course of accumulation and consumption in muscle tissue of Japanese eel during the period of experiment and the accumulation was related with the swimming of females. The more the females swam, the more AA was accumulated in muscle tissues. DHA levels of muscle tissues in Japanese eels were the highest, its change was remarkably different between treated groups and its level in control reached up to (123.91+7.29) mg/g DMW, accounting for 32.52 percent of total lipids. However, its level in I&GD group dropped at (10.59+0.85) mg/g DMW at the end of experiment. Relativity analyses indicated that the relativities between GSI and the levels of total lipids, PUFA, DHA and EPA were all showed in some extent negative relativities, but the closest factor was DHA, r = -0.952(P<0.01 ,n =5) , the most distant one was EPA, r =-0.882 (P<0.05,n=5). Therefore, it was indicated that DHA was the most important fatty acid during the period of gonadal development in Japanese eel. Analyzing for energy distribution considered that the lipid consumption for basal metabolization (L_(BM)) accounted for 34.68% of total lipids, gonadal development (L_(GD)) accounted for 32.94% and swimming energy (L_(SE)) accounted for 9.79%. After finished spawning, the muscle of females was also reserved 23.04% of total lipids. Therefore, it can be undoubted that Japanese eels not only can provide enough energy to finish the spawning migration so far as over 2000 sea miles but also make the gonadal normal development without intake any food.