Effects of sodium citrate, potassium citrate, and citric acid in preventing experimental calcium oxalate urolithiasis in rats

Abstract

グリコール酸食をウィスター系ラットに4週間投与すると腎石灰化症および尿路結石を著明に認める.この食餌にクエン酸塩を添加すると結石形成が抑制される.クエン酸のみの添加ではこの抑制作用がほとんど認められなかった.実験食投与中は尿中蓚酸濃度は, グリコール酸のみの対照群に比してクエン酸およびその塩投与群では高かった.尿中クエン酸濃度はクエン酸塩投与群では高く, 対照群とクエン酸投与群では低かった.尿中のカルシウムおよびマグネシウム濃度は各群間に有意差は認められなかった.したがって, クエン酸塩投与は尿中の蓚酸濃度を多少増加させるが, 尿中のクエン酸濃度を著しく増加させるため尿の過飽和状態が低下し, 腎石灰化症および尿路結石形成を抑制する

Male Wistar-strain rats which had been fed a glycolic-acid diet developed severe nephrocalcinosis with urinary calculi within 4 weeks. Rats fed the same diet with citrate salts added had, however, either slight or no nephrocalcinosis without any stones in the urinary system. Nephrocalcinosis intermediate between those in the citrate groups and the glycolic-acid group, with some urinary calculi, was observed in the citric-acid group. During the experiment, the urinary oxalate concentration increased markedly and was higher in the citrate and citric-acid than in the glycolic-acid group. The urinary citrate concentration was significantly higher in the citrate groups and lower in the citric acid and glycolic-acid groups. Therefore, citrate salts can be concluded to inhibit nephrocalcinosis and calculi formation as a result of decreased urinary saturation by means of increase in urinary citrate, in spite of a slight increase in the urinary oxalate.