tailieunhanh - Báo cáo khoa học: " Clinical review: Renal tubular acidosis – a physicochemical approach"

Tuyển tập các báo cáo nghiên cứu về y học được đăng trên tạp chí y học Critical Care giúp cho các bạn có thêm kiến thức về ngành y học đề tài: Clinical review: Renal tubular acidosis – a physicochemical approach. | Available online http content 9 6 573 Review Clinical review Renal tubular acidosis - a physicochemical approach Troels Ring1 Sebastian Frische2 and Soren Nielsen3 1 Consultant Department of Nephrology Aalborg Hospital Aalborg Denmark 2Assistant Professor The Water and Salt Research Center Institute of Anatomy University of Aarhus Aarhus Denmark 3Professor of Cell Biology and Pathophysiology Director The Water and Salt Research Center Institute of Anatomy University of Aarhus Aarhus Denmark Corresponding author Troels Ring tring@ Published online 25 August 2005 This article is online at http content 9 6 573 2005 BioMed Central Ltd Critical Care 2005 9 573-580 DOI cc3802 Abstract The Canadian physiologist PA Stewart advanced the theory that the proton concentration and hence pH in any compartment is dependent on the charges of fully ionized and partly ionized species and on the prevailing CO2 tension all of which he dubbed independent variables. Because the kidneys regulate the concentrations of the most important fully ionized species K Na and Cl- but neither CO2 nor weak acids the implication is that it should be possible to ascertain the renal contribution to acid-base homeostasis based on the excretion of these ions. One further corollary of Stewart s theory is that because pH is solely dependent on the named independent variables transport of protons to and from a compartment by itself will not influence pH. This is apparently in great contrast to models of proton pumps and bicarbonate transporters currently being examined in great molecular detail. Failure of these pumps and cotransporters is at the root of disorders called renal tubular acidoses. The unquestionable relation between malfunction of proton transporters and renal tubular acidosis represents a problem for Stewart theory. This review shows that the dilemma for Stewart theory is only apparent because transport of acid-base equivalents is accompanied by .