Study on mechanism of bone mineralabsorption following urinary diversion

为了阐明肠段尿改道和代谢性酸中毒引起的骨脱矿机制，我们用DEXA测量了腰椎的骨矿物质密度，并在0、2、4、8周测量了尿吡啶和血清骨钙素、钙和磷酸盐。雄性大鼠分为5组；对照组不做任何处理，酸中毒组用1.5% NII4Cl水处理，增强组用回肠末端增加膀胱，假手术组切除回肠末端，再吻合组切开回肠后再吻合。增强组和假手术组骨矿物质密度在2周时下降，而酸中毒组在2个月时没有变化。各组尿吡啶含量无差异。血清钙在对照组和再吻合组升高，酸中毒组无变化，增强组和假手术组降低。强化组骨脱矿模式与假手术组相似，而与酸中毒组不同。这些数据表明，切除回肠末端可能导致骨脱矿，并伴有血清钙的降低。

To clarify the mechanism of bone demineralization following urinary diversions using intestinal segments and by metabolic acidosis, the bone mineral densities of the lumber spine were measured with DEXA, and urinary pyridinium and serum osteocalcin, calcium, and phosphate were measured at 0, 2, 4, 8-week. Male rats were divided into 5 groups ; the control group without any treatment, the acidosis group treated with 1.5% NII4Cl water, the augmentation group the bladder of which was augmented with the terminal ileum, the sham group a similar length of the terminal ileum of which was removed, and the re-anastomosis group the ileum of which was incised and then re-anastomosed. The bone mineral densities of the augmentation and sham groups decreased at 2-week, whereas those of the acidosis group had no change in two months. No differences were found in urinary pyridinium among all groups. Serum calcium increased in the control and re-anastomosis groups, had no change in the acidosis group, and decreased in the augmentation and sham groups. The bone demineralization of the augmentation group had a similar pattern to the sham group rather than the acidosis group. These data indicated that the removal of the terminal ileum might induce bone demineralization associated with serum calcium decrease.