Hanai Miho, Kubo Katsuharu, Esashi Takatoshi
Department of Biological Science, State University of New York, College at Brockport, 350 New Campus Drive, Brockport, NY 14420, USA.
J Nutr Sci Vitaminol (Tokyo). 2003 Dec;49(6):388-96. doi: 10.3177/jnsv.49.388.
The purpose of this experiment was to clarify the effects of nutrients on the gonadal development of male rats kept under constant darkness as a model of disturbed daily rhythm. Protein, methionine, vitamins, minerals and fat were selected as experimental factors, and eight kinds of diets were prepared based on the L8(2(7)) type orthogonal array. Dietary contents of the nutrients were normal (AIN-76 diet) or 1/3 to 1/2 of the normal content. Four-week-old rats (Fischer 344 strain) were kept under constant darkness for 4 wk. Control groups were kept under 12-h light/dark cycle. After 4 wk, the gonadal weights and serum testosterone content were evaluated. The effects of nutrients on gonadal development in rats differed between constant darkness groups (D-groups) and normal lighting groups (N-groups). Among the D-groups, the highest value for testes weight was observed under the normal protein, methionine added, low vitamin, low mineral and normal fat diet. The lowest value for testes weight was observed under the low protein, methionine added, normal vitamin, normal mineral and low fat diet. Among the N-groups, the highest value for testes weight was observed under the normal protein and no methionine diet, and the lowest value was observed under the low protein and no methionine diet. Among the D-groups, the highest value for serum testosterone was observed under the normal protein and low mineral diet. In the N-groups, serum testosterone was not affected by nutritional factors. It became clear that the amounts of protein, methionine, vitamins, minerals, and oil which are necessary for the gonadal development of growing male rats change when kept in constant darkness.
本实验的目的是阐明营养素对持续处于黑暗环境中的雄性大鼠性腺发育的影响，以此作为日常节律紊乱的模型。选择蛋白质、蛋氨酸、维生素、矿物质和脂肪作为实验因素，并基于L8(2(7))型正交表制备了八种日粮。营养素的日粮含量为正常水平（AIN - 76日粮）或正常含量的1/3至1/2。将四周龄大鼠（Fischer 344品系）置于持续黑暗环境中4周。对照组置于12小时光照/黑暗循环环境中。4周后，评估性腺重量和血清睾酮含量。营养素对大鼠性腺发育的影响在持续黑暗组（D组）和正常光照组（N组）之间存在差异。在D组中，正常蛋白质、添加蛋氨酸、低维生素、低矿物质和正常脂肪日粮条件下观察到睾丸重量的最高值。在低蛋白质、添加蛋氨酸、正常维生素、正常矿物质和低脂肪日粮条件下观察到睾丸重量的最低值。在N组中，正常蛋白质且无蛋氨酸日粮条件下观察到睾丸重量的最高值，低蛋白质且无蛋氨酸日粮条件下观察到最低值。在D组中，正常蛋白质和低矿物质日粮条件下观察到血清睾酮的最高值。在N组中，血清睾酮不受营养因素影响。结果表明，生长中的雄性大鼠在持续黑暗环境中时，性腺发育所需的蛋白质、蛋氨酸、维生素、矿物质和油脂的量会发生变化。
