Abstract—

The effect of melatonin on the initial (feeding) and central link (digestion) of exotrophy in juvenile common carp Cyprinus carpio was investigated in parallel for the first time. The effect of intraperitoneal injections of the hormone at a concentration of 100 and 200 ng/g of body weight on locomotor activity and food consumption, as well as on the activity of digestive enzymes in the intestinal mucosa and chyme, was studied. It was shown that five hours after the administration of the hormone, food consumption and the activity of digestive enzymes in the intestinal mucosa decrease, while the locomotor activity of fish and the enzymatic activity of the chyme do not change significantly. Food consumption is significantly (by factor of 2.2) reduced as a result of the administration of the hormone at a dose of 200 ng/g body weight. The level of caseinolytic and hemoglobinolytic activity of peptidases and amylolytic activity of the intestinal mucosa at this dose also decrease significantly: by 27, 54 and 42%, respectively, compared to the control. The injection of melatonin at a dose of 100 ng/g causes a slight decrease in the level of enzymatic activity of the intestinal mucosa. The mechanisms of the effect of melatonin on the processes of exotrophy in fish are discussed.

中文翻译：

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褪黑素对鲤鱼鲤鱼外生过程的影响

摘要-

褪黑素对幼年鲤鲤外生营养的初期（进食）和中枢环节（消化）的影响进行了首次平行调查。研究了腹腔内注射浓度为100和200 ng / g体重的激素对运动能力和食物消耗以及肠粘膜和食糜中消化酶活性的影响。结果表明，激素给药后五小时，肠道粘膜的食物消耗和消化酶的活性降低，而鱼类的运动能力和食糜的酶活性没有明显变化。通过以200 ng / g体重的剂量服用激素，可显着减少食物消耗（减少2.2倍）。在此剂量下，肽酶的酪蛋白水解和血红蛋白溶解活性水平以及肠粘膜的淀粉分解活性水平也显着降低：与对照相比分别降低了27％，54％和42％。以100 ng / g的剂量注射褪黑激素会使肠粘膜的酶促活性水平略有下降。讨论了褪黑激素对鱼类外生过程的影响机理。