ETHNIC DIFFERENCES IN RENAL FUNCTION IN AFRICAN AND CAUCASIANS

这个子项目是许多研究子项目中的一个 由NIH/NCRR资助的中心赠款提供的资源。子项目和 研究者（PI）可能从另一个NIH来源获得了主要资金， 因此可以在其他CRISP条目中表示。所列机构为 研究中心，而研究中心不一定是研究者所在的机构。 与欧洲裔美国人相比，非洲裔美国人的高血压患病率和发病率较高，高血压并发症的发生率也较高  特别是中风和终末期肾病。此外，一些研究表明，血压可能对非裔美国人的钠缺乏或盐负荷比欧洲裔美国人更敏感。然而，研究人员并没有在血压正常和高血压参与者或女性和男性中持续观察到这种种族差异。饮食方法阻止高血压（DASH）  在钠试验中，非裔美国人对饮食钠限制的血压反应比非裔美国人更大，但仅限于对照饮食，而不是DASH饮食。我们随机招募了南非黑人血统的核心家庭和白色比利时血统的核心家庭。我们测量了钠排泄分数（FENa），并根据内源性锂和肌酐的清除率估计了近端（RNaprox）和远端（RNadist）肾小管中的肾钠重吸收分数。在多变量分析中，我们研究了RNaprox和RNadist与钠排泄分数（FENa）的关系，并估计了RNaprox和RNadist的遗传度。沿着肾单位的节段性钠重吸收是高度遗传的，但在近端和后近端小管的调节能力在白人和黑人之间是不同的。在过滤后的钠负荷中，黑人参与者在近端肾单位中的重吸收多于白色参与者，而在近端后肾单位中的重吸收较少。 在另一项研究中，研究了非洲家庭成员和无关的高加索人，研究了ABCB 1基因及其周围的SNP与肾小球滤过率（GFR）的关系。 2677 T和3435 T等位基因与GFR显著升高相关，这表明人类肾病的新候选基因。

This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. African Americans, as compared to European Americans, have a higher prevalence and incidence of hypertension and experience higher rates of hypertensive complications  in particular, stroke and end-stage renal diseasel. Furthermore, several studies have suggested that blood pressure might be more sensitive to sodium depletion or salt loading in African Americans than in European Americans. However, researchers have not consistently observed this ethnic difference in normotensive and hypertensive participants or in women and men. In the Dietary Approaches to Stop Hypertension (DASH)  Sodium Trial, African Americans showed a greater blood pressure response to dietary sodium restriction than non-African Americans, but only on the control diet, and not on the DASH diet. We randomly recruited nuclear families of black South African ancestry and nuclear families of white Belgian ancestry. We measured the fractional excretion of sodium (FENa) and estimated the fractional renal sodium reabsorption in the proximal (RNaprox) and distal (RNadist) tubules from the clearances of endogenous lithium and creatinine. In multivariable analyses, we studied the relation of RNaprox and RNadist with the fractional excretion of sodium (FENa) and estimated the heritability of RNaprox and RNadist. Segmental sodium reabsorption along the nephron is highly heritable, but the capacity for regulation in the proximal and postproximal tubules differs between whites and blacks. Of the filtered sodium load, black participants reabsorb more than white participants in the proximal nephron and less postproximally. In another study, studying both African family members and unrelated Caucasions, SNPs in and around the ABCB1 gene were investigated for association with glomerular filtration rate (GFR). The 2677T and 3435T alleles were associated with significantly higher GFR, pointing to a new candidate gene for nephropathy in humans.