Canzanello V J, Kraut J A, Holick M F, Johns C, Liu C C, Madias N E
Department of Medicine, Tufts University School of Medicine, Boston, MA, USA.
J Lab Clin Med. 1995 Jul;126(1):81-7.
Chronic metabolic acidosis typically results in hypercalciuria and negative calcium balance. The impact of chronic respiratory acidosis on calcium metabolism has been less well studied. To address this issue, metabolic balance and static bone histomorphometric data were obtained during a 14-day exposure of rats to 10% CO2 (blood pH 7.33, PaCO2 83 mm Hg) and were compared with pair-fed controls. All rats were fed a 0.8% calcium diet. Urinary calcium excretion (mg/period, mean +/- SEM) was increased during both week 1 and week 2 (16 +/- 3 vs 9 +/- 1 and 16 +/- 2 vs 9 +/- 1, CO2 group vs controls, respectively [p < 0.05]). Net intestinal calcium absorption (intake minus fecal excretion) was increased throughout the period of hypercapnia (week 1, 213 +/- 19 mg vs 135 +/- 15 mg; week 2, 135 +/- 16 mg vs 43 +/- 14 mg; and cumulatively, 344 +/- 27 mg vs 178 +/- 20 mg, CO2 group vs controls [p < 0.01]). As a consequence of the marked increment in intestinal calcium absorption during hypercapnia, mean net calcium balance was more positive than that of controls throughout the study (week 1, 197 +/- 18 mg vs 126 +/- 15 mg; week 2, 120 +/- 15 mg vs 34 +/- 15 mg; and cumulatively, 317 +/- 25 mg vs 159 +/- 20 mg, CO2 group vs controls, respectively [p < 0.01]). There were no significant differences in calcium intake, plasma total calcium, immunoreactive parathyroid hormone, 25-hydroxyvitamin D, or creatinine clearance between the two groups.(ABSTRACT TRUNCATED AT 250 WORDS)
慢性代谢性酸中毒通常会导致高钙尿症和负钙平衡。慢性呼吸性酸中毒对钙代谢的影响研究较少。为解决这一问题，在大鼠暴露于10%二氧化碳（血pH 7.33，动脉血二氧化碳分压83 mmHg）14天期间获取了代谢平衡和静态骨组织形态计量学数据，并与配对喂养的对照组进行比较。所有大鼠均喂食0.8%钙的饮食。在第1周和第2周，二氧化碳组大鼠的尿钙排泄量（mg/周期，均值±标准误）均增加（分别为16±3 vs
9±1和16±2 vs 9±1，二氧化碳组vs对照组，[p<0.05]）。在整个高碳酸血症期间净肠道钙吸收（摄入量减去粪便排泄量）增加（第1周，213±19 mg vs 135±15 mg；第2周，135±16 mg vs 43±14 mg；累积值，344±27 mg vs 178±20 mg，二氧化碳组vs对照组，[p<0.01]）。由于高碳酸血症期间肠道钙吸收显著增加，在整个研究过程中，二氧化碳组的平均净钙平衡比对照组更正（第1周，197±18 mg vs 126±15 mg；第2周，120±15 mg vs 34±15 mg；累积值，317±25 mg vs 159±20 mg，二氧化碳组vs对照组，[p<0.01]）。两组之间的钙摄入量、血浆总钙、免疫反应性甲状旁腺激素、25-羟维生素D或肌酐清除率无显著差异。（摘要截断于250字）
