The Gansu Zokor (myospalax Cansus) Analysis, Bone And Blood Calcium And Phosphorus Metabolism

Ca and P are not noly the basic composition elements of skeletons in mammals, but also the modulators which play important roles in animals' life. As the essential part of Ca-P metabolism, the Ca-P flux between skeletons and other organs, tissues, as the plasma, the gut and the kidney, which is the key regulator to maintain the mineral balance, is also the essential part of mineral metabolism. Vitamin D₃ levels are generally considered imperative for mineral metabolism in most animals, particularly to the surface-dwelling animals, because of its central role via mediating absorption and reabsorption of mineral respectively in intestine and kidney, and direction to the skeleton mineral. Subterranean rodents lead a strictly chthonic existence, perpetually dark and devoid of ultraviolet radiation, and are herbivorous. They appear to be naturally deficient in vitamin D3, for the fact that they cannot synthesize vitamin D₃ endogenously or attain it from the food. From the study in bathyergid subterranean rodents, we see that the levels of vitamin D₃ in these species are very low, and their mineral metabolism seems insensitive to vitamin D3.Gansu Zokor (Myospalax cansus) is a special rodent living in loess plateau of China, which leads a solitary fossorial rodent inhabiting in its own tunnel system all its life. We choose Gansu Zokor as experimental object to investigate its mechanism of mineral metabolism. We examined the amounts of Ca, P in femur, the concentration of Ca, P, ALP in plasma of Gansu Zokors and SD rats, both of which are separately divided into control group, Ca adding group, VD adding group and Ca+VD adding group in random. Then, we carry out significance of difference test and regression analysis. The results are as follow:1 The femur Ca, P in Ca adding group, VD adding group and Ca+VD adding group are significantly higher than that in control group of Gansu Zokors.2 The femur Ca in VD adding group and Ca+VD adding group are significantly higher than that in Ca adding group and control group of SD rats. The femur P in VD adding group, Ca+VD adding group and control group are significantly higher than that in Ca adding group of SD rats.3 There are no significant differences of the plasma Ca, P among the four groups of Gansu Zokors. The plasma ALP in Ca adding group, VD adding group and Ca+VD adding group are significantly higher than that in control group of Gansu Zokors.4 Among SD rats, the plasma Ca in VD adding group and Ca+VD adding group are significantly higher than that in Ca adding group and control group, the plasma P in Ca+VD adding group is significantly lower than that in VD adding group and control group, the plasma ALP in Ca adding group and Ca+VD adding group are significantly higher than that in VD adding group and control group 5 There shows a bad linear correlation between femur Ca and plasma Ca, femur P and plasma P in four groups of Gansu Zokors. Also, the linear correlation between femur Ca, P, plasma Ca, P and VD intake in VD adding group and Ca+VD adding group are not good. The linear correlation between femur Ca, P and Ca, P intake in four groups of Gansu Zokors are good. But, the linear correlation between plasma Ca, P and Ca, P intake in four groups of Gansu Zokors are not good.6 There shows a bad linear correlation between femur Ca and plasma Ca, femur P and plasma P in four groups of SD rats. However, the linear correlation between femur Ca, P, plasma Ca, P and VD intake in VD adding group and Ca+VD adding group display good and strong.By all the results above, it suggests that Gansu Zokor has a high absorb efficiency to Ca and P, and effectively transfer them to skeleton then making them deposit. In combination with the regression analysis, we are implied that the absorption to Ca and P in Gansu Zokor may lead a VD₃-independent, nonsaturable and passive uptake path. This may be adequate to the mineral requirements and maintain mineral homeostasis in the absence of vitamin D₃ of this underground rodent.