Shinoda H, Seto H
Miner Electrolyte Metab. 1985;11(3):158-66.
Diurnal fluctuations in serum Ca, inorganic phosphorus, Mg, and alkaline phosphatase activity and their relations to lighting and feeding schedules were investigated in nocturnal rats and diurnal asiatic chipmunks. The following results were obtained: all parameters in the animals fed ad libitum and adapted to a regulated light-dark cycle (with light from 7.00 to 19.00 h) showed diurnal rhythms; under the same experimental condition, the patterns of the rhythms in the nocturnal rat and the diurnal asiatic chipmunk were nearly 180 degrees out of phase with each other; under the continuous lighting condition for more than 10 days, the diurnal rhythms of the parameters in rats decreased in their amplitudes, and phase shifts or marked modulations in the diurnal curves occurred when the time of availability of food was restricted from 9.00 to 17.00 h without altering the lighting schedule. The above findings support an idea that the rhythmicity is one of the essential features involved in the Ca metabolism. It is demonstrated that the environmental photofraction is one of the essential factors in generating or in maintaining the circadian rhythm of Ca metabolism as in other physiological processes and that the feeding time also could have a marked effect on the diurnal rhythm in the Ca metabolism.
在夜行性大鼠和昼行性亚洲花栗鼠中研究了血清钙、无机磷、镁和碱性磷酸酶活性的昼夜波动及其与光照和进食时间表的关系。获得了以下结果：随意进食并适应规定明暗周期（7:00至19:00有光照）的动物的所有参数均显示出昼夜节律；在相同实验条件下，夜行性大鼠和昼行性亚洲花栗鼠的节律模式彼此相差近180度；在连续光照超过10天的情况下，大鼠参数的昼夜节律振幅减小，并且当食物供应时间从9:00限制到17:00而不改变光照时间表时，昼夜曲线出现相移或明显的调节。上述发现支持了节律性是钙代谢所涉及的基本特征之一的观点。结果表明，环境光部分是像其他生理过程一样产生或维持钙代谢昼夜节律的基本因素之一，并且进食时间也可能对钙代谢的昼夜节律产生显著影响。
