Abstract

The effects of the photoperiodic conditions in northwestn Russia (Republic of Karelia, Petrozavodsk) and exogenous melatonin on the body weight and the physiological and biochemical parameters of blood serum in males and females of the Syrian hamster (Mesocricetus auratus) were studied. The animals were divided into two groups: control (LD: 12 h light/12 h darkness) and experimental (NL: decrease in the duration of the daylight phase from 19:36/4:24 to 12/12, which was typical for the Republic of Karelia from June 25, 2018, to September 25, 2018). Each group was divided into two subgroups: hamsters of the first subgroup received drinking water without melatonin (LD, NL), the second group received melatonin (100 μg/animal) at night (LD + mel, NL + mel). Males were found to be the most sensitive to the change in the photoperiod: the NL conditions led to an increase in feed intake, and body weight in the middle of the experiment, and total cholesterol and urea levels by the end of the experiment, while the activities of amylase, lactate dehydrogenase, and aspartate aminotransferase in the blood were lower than in LD. The melatonin effect on the studied parameters depended on the conditions and sex of the animals. Melatonin treatment of the NL-females caused enhancement in the effect of the light regime and increase in most of the biochemical parameters of blood serum compared to the control as well as an increase in body weight for the entire study period. The use of melatonin in the LD conditions had a negative effect on the Syrian hamsters, causing intensification of metabolic processes and, as a result, a significant decrease in body weight in both males and females. In our opinion, the revealed differences between the experimental groups are primarily associated with a change in the synthesis of melatonin by the pineal gland in various light conditions.

中文翻译：

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俄罗斯西北地区光周期条件和外源褪黑激素对叙利亚仓鼠（Mesocricetus auratus）生理生化指标的影响

摘要

俄罗斯西北部（卡累利阿共和国，彼得罗扎沃茨克）的光周期条件和外源褪黑素对叙利亚仓鼠（Mesocricetus auratus）雌雄的体重和血清生理生化指标的影响）进行了研究。将动物分为两组：对照组（LD：12 h光照/ 12 h黑暗）和实验组（NL：白天的持续时间从19：36/4：24减少到12/12，这对于卡累利阿共和国（2018年6月25日至2018年9月25日）。每组分为两个亚组：第一个亚组的仓鼠接受不含褪黑素的饮用水（LD，NL），第二个组在夜间接受褪黑素（100μg/动物）（LD + mel，NL + mel）。发现雄性对光周期的变化最敏感：NL条件导致饲料摄入量增加，实验中期体重增加，实验结束时总胆固醇和尿素水平升高，而血液中淀粉酶，乳酸脱氢酶和天冬氨酸转氨酶的活性低于LD。褪黑素对研究参数的影响取决于动物的条件和性别。与对照组相比，褪黑激素对NL-雌性动物的治疗导致光疗效果的增强和大多数血清生化参数的增加，以及整个研究期间体重的增加。在LD条件下使用褪黑激素对叙利亚仓鼠有负面影响，导致代谢过程加剧，结果，男性和女性的体重均显着下降。我们认为，实验组之间揭示的差异主要与松果体在各种光照条件下褪黑激素合成的变化有关。与对照组相比，褪黑激素对NL-雌性动物的治疗导致光疗效果的增强和大多数血清生化参数的增加，以及整个研究期间体重的增加。在LD条件下使用褪黑激素对叙利亚仓鼠有负面影响，导致代谢过程加剧，结果，男性和女性的体重均显着下降。我们认为，实验组之间揭示的差异主要与松果体在各种光照条件下褪黑激素合成的变化有关。与对照组相比，褪黑激素对NL-雌性动物的治疗导致光疗效果的增强和大多数血清生化参数的增加，以及整个研究期间体重的增加。在LD条件下使用褪黑激素对叙利亚仓鼠有负面影响，导致代谢过程加剧，结果，男性和女性的体重均显着下降。我们认为，实验组之间揭示的差异主要与松果体在各种光照条件下褪黑激素合成的变化有关。