小体鲟雌性亲鱼性腺不同发育时期消化酶分布及其活性的研究

Activities of digestive enzymes at different developmental stages in sterlet Acipenser ruthenus Linnaeus

采用酶学方法测定了不同性腺发育时期（Ⅱ~Ⅴ期）小体鲟Acipenser ruthenus Linnaeus雌性亲鱼胃、肠道和幽门盲囊中蛋白酶、淀粉酶、脂肪酶的活性,并分析了3种酶活性随性腺发育时期的变化规律。结果表明：小体鲟雌性亲鱼5种消化器官中的蛋白酶活性以性腺发育Ⅱ期、Ⅲ期较高,淀粉酶活性以性腺发育Ⅴ期较高,脂肪酶活性以性腺发育Ⅴ期、Ⅱ期较高,3种酶活性均以性腺发育Ⅳ期较低;各性腺发育期,雌性亲鱼的蛋白酶活性均以幽门盲囊、后肠中较高,其次为胃、中肠,淀粉酶活性以中肠中最高,其次为胃、幽门盲囊、前肠、后肠,脂肪酶活性均以幽门盲囊中最高,其次为中肠、前肠、胃、后肠。研究表明,小体鲟雌性亲鱼在性腺发育Ⅱ期、Ⅲ期对食物中蛋白质和碳水化合物需求较高,而性腺发育周期中对脂类物质的需求Ⅴ期最高,其次是Ⅱ期,总体来说,小体鲟亲鱼在整个性腺发育时期对脂肪的需求量较高。

Activities of protease, amylase and lipase were analyzed and compared in stomach, intestine and pyloric caecum in female sterlet Acipenser ruthenus broodstock with different developmental phases （Ⅱ-Ⅴ） . The results showed that the maximal protease activity was observed in the broodstock withⅡphase ovary, and that higher pro-tease activity in the broodstock withⅢphase ovary. The amylase activity was found to be higher in the broodstock with Ⅴphase ovary, and the lipase activity to be higher in broodstock withⅤandⅡphase ovaries. The minimal activities of protease, amylase and lipase were observed in the broodstock with Ⅳ phase ovary, and in the brood-stock with different gonadal developmental phases higher protease activity was observed in pyloric caecum and hind-gut, followed by in the stomach and midgut. The maximal amylase activity, however, was found in hindgut, fol-lowed by in the stomach, pyloric caecum, foregut and hindgut. The maximal lipase activity was observed in the py-loric caecum, and higher lipase activity was found in the intestine and stomach. The findings indicated that the sterlet broodstock with Ⅱ and Ⅲ phase ovary required more dietary protein and carbohydrate, while the sterlet broodstock with Ⅴor Ⅱphase ovary needed more lipid. During the whole gonadal development, the sterlet brood-stock required more dietary lipid.