Haramati A, Nienhuis D
Am J Physiol. 1984 Oct;247(4 Pt 2):F596-601. doi: 10.1152/ajprenal.1984.247.4.F596.
Clearance experiments were performed in acutely thyroparathyroidectomized rats to evaluate the renal handling of phosphate during respiratory acidosis (R ACID) and alkalosis (R ALK) in rats fed either a normal (0.7%) or low (0.07%) phosphate diet for 4 days. Different acid-base states were achieved by varying the mixture of carbon dioxide in the inspired air. Each group received graded infusions of phosphate to control for differences in plasma phosphate (PPi) and to determine the maximum transport capacity of phosphate reabsorption (TmPi/GFR). In rats fed a normal phosphate diet, PPi and the fractional excretion of phosphate (FEPi) were significantly greater in R ACID than in R ALK. However, there were no differences between R ACID and R ALK when FEPi was evaluated as a function of the PPi, and values for TmPi/GFR during R ACID were not different from those during R ALK. In rats fed low phosphate diet, PPi during R ACID was significantly greater than during R ALK, yet FEPi was less than 1% in all groups due to an adaptive increase in TmPi/GFR. Further, the TmPi/GFR was similar irrespective of the acid-base state. We conclude that acute respiratory acid-base changes do not alter the intrinsic capacity of the kidney to reabsorb phosphate.
对急性甲状旁腺切除的大鼠进行清除实验，以评估在呼吸性酸中毒（R ACID）和碱中毒（R ALK）期间，喂食正常（0.7%）或低（0.07%）磷饮食4天的大鼠对磷的肾脏处理情况。通过改变吸入空气中二氧化碳的混合物来实现不同的酸碱状态。每组接受分级输注磷酸盐，以控制血浆磷酸盐（PPi）的差异，并确定磷重吸收的最大转运能力（TmPi/GFR）。在喂食正常磷饮食的大鼠中，R ACID时的PPi和磷的分数排泄（FEPi）显著高于R ALK。然而，当将FEPi作为PPi的函数进行评估时，R ACID和R ALK之间没有差异，并且R ACID期间的TmPi/GFR值与R ALK期间的值没有差异。在喂食低磷饮食的大鼠中，R ACID时的PPi显著高于R ALK，但由于TmPi/GFR的适应性增加，所有组的FEPi均小于1%。此外，无论酸碱状态如何，TmPi/GFR均相似。我们得出结论，急性呼吸酸碱变化不会改变肾脏重吸收磷的内在能力。
