Lemann Jacob, Bushinsky David A, Hamm L Lee
Nephrology Section, Tulane University School of Medicine, 2601 St. Charles Ave., New Orleans, LA 70130-5927, USA.
Am J Physiol Renal Physiol. 2003 Nov;285(5):F811-32. doi: 10.1152/ajprenal.00115.2003.
The sources and rates of metabolic acid production in relation to renal net acid excretion and thus acid balance in humans have remained controversial. The techniques and possible errors in these measurements are reviewed, as is the relationship of charge balance to acid balance. The results demonstrate that when acid production is experimentally increased among healthy subjects, renal net acid excretion does not increase as much as acid production so that acid balances become positive. These positive imbalances are accompanied by equivalently negative charge balances that are the result of bone buffering of retained H+ and loss of bone Ca2+ into the urine. The data also demonstrate that when acid production is experimentally reduced during the administration of KHCO3, renal net acid excretion does not decrease as much as the decrease in acid production so that acid balances become negative, or, in opposite terms, there are equivalently positive HCO3- balances. Equivalently positive K+ and Ca2+ balances, and thus positive charge balances, accompany these negative acid imbalances. Similarly, positive Na+ balances, and thus positive charge balances, accompany these negative acid balances during the administration of NaHCO3. These charge balances are likely the result of the adsorption of HCO3- onto the crystal surfaces of bone mineral. There do not appear to be significant errors in the measurements.
与肾脏净酸排泄相关的代谢酸产生的来源和速率，以及由此产生的人体酸平衡问题一直存在争议。本文综述了这些测量中的技术和可能存在的误差，以及电荷平衡与酸平衡的关系。结果表明，当在健康受试者中实验性地增加酸产生时，肾脏净酸排泄的增加幅度不如酸产生的增加幅度大，因此酸平衡变为正值。这些正的失衡伴随着等量的负电荷平衡，这是由于保留的H⁺由骨骼缓冲以及骨Ca²⁺流失到尿液中所致。数据还表明，当在给予KHCO₃期间实验性地减少酸产生时，肾脏净酸排泄的减少幅度不如酸产生的减少幅度大，因此酸平衡变为负值，或者相反，存在等量的正HCO₃⁻平衡。这些负的酸失衡伴随着等量的正K⁺和Ca²⁺平衡，从而产生正电荷平衡。同样，在给予NaHCO₃期间，这些负的酸平衡伴随着正的Na⁺平衡，从而产生正电荷平衡。这些电荷平衡可能是由于HCO₃⁻吸附到骨矿物质的晶体表面所致。测量中似乎不存在重大误差。
