Characteristics of physiological and biochemical properties and metabolic rhythms in hereditary microphthalmic rat.

对冬雨品系小眼鼠的生理生化和激素特性、自发活动节律和某些代谢酶活性进行了观察。遗传性小眼症大鼠是我们实验室通过兄妹交配产生的。与来自同一品系的正常大鼠相比，该突变体的生长受到抑制。除葡萄糖代谢外，该突变体具有几乎正常的生化和生理功能。突变体的蛋白质、脂肪和矿物质代谢等生化参数对限制进食的反应与正常大鼠没有不同。正常大鼠运动节律基本呈夜间节律，而小眼症大鼠大部分表现为自由奔跑节律，少数表现为心律失常。当在LD周期的光周期中仅限制食物获取6小时时，正常和遗传性盲人r…更多的AT逐渐产生了新的运动节奏模式，在这种模式中，动物在光照阶段表现得更加活跃。突变体的鸟氨酸脱羧酶活性没有明显的昼夜波动。正常大鼠的松果体酶活性和5-羟色胺N-乙酰转移酶的mRNA水平在夜间比白天高50倍以上，但有些突变体表现出高度丰富的mRNA，而另一些突变体在光照和黑暗期间都没有检测到mRNA的含量，酶活性的昼夜变化规律相似，表明突变体的节律变得自由运行、不同步。而松果体酶活性在主观夜间升高，在主观白天受到抑制。至于亚昼夜节律，突变大鼠表现出不规则的性周期，以促黄体生成素(L H)峰值估计。经酪氨酸羟化酶免疫组织化学检测和单胺类物质含量测定，突变大鼠黑质和下丘脑儿茶酚胺的代谢特征与正常大鼠基本一致。这些结果表明，小眼球突变大鼠保持了由于限制获取食物而导致的昼夜节律变化和同步的能力，即使它们完全失去了对生物钟的视神经和视觉输入。该遗传性小眼大鼠可作为时间生物学研究的模型实验动物。较少

The characteristics in the physiological, biochemical and hormonal properties, and the rhythms of spontaneous locomotor activity and some metabolic enzyme activities were examined in the microphthalmic rat of the Donryu strain. The hereditary microphthalmic rats were produced through brother-sister mating in our laboratory. The growth of the mutant was retarded as compared to that of normal rat from the same strain. The mutant exhibited almost normal properties of biochemical and physiological functions except for glucose metabolism. Responses of the biochemical parameters of protein, lipid and mineral metabolism to restricted food access in the mutant did not differ from those in normal rats. Normal rats showed basically nocturnal pattern of the locomotor activity rhythm, but most of microphthalmic rats manifested free-running rhythms and a few of them showed arrhythmic. When food access was restricted only for 6 h in the light period of the LD cycle, the normal and hereditary blind r … More ats generated gradually new patterns of the locomotor rhythm in which the animals showed to be more active in the light phase. The activities of ornithine decarboxylase in the mutant were found not to undergo a remarkable circadian fluctuation. The pineal enzyme activities and the mRNA levels of serotonin N-acetyltransferase in normal rats increased more than 50-fold at night than the day value, but some of the mutant showed highly abundant the mRNA but the others exhibited no detectable amount of the mRNA both in the light and in the dark period, and similar circadian patterns were found in enzyme activity, suggesting that the rhythms in the mutant became free-running, asynchronous. While, the pineal enzyme activity increased at the subjective night but depressed at the subjective day. As for the infradian rhythms, the mutant rat manifested irregular sexual cycle estimated by lutenizing hormone (LH) surge. By immunohistochemical detection of tyrosine hydroxylase and the concentrations of monoamines, the metabolic aspects of catecholamine in the substantia nigra and hypothalamus in the mutant were approximately the same as those of normal rats. Thesr results suggest that microphthalmic mutant rats maintain the ability to shift and to synchronize their circadian phases induced by restricted access to food, even if they completely lack their optic nerve and visual input to the circadian clock. This hereditary microphthalmic rat will be useful as the model experimental animals for The studies of chronobiology. Less