The sites of action of angiotensin II along the nephron are not well defined and both proximal and distal effects are suggested. Using a microassay that permits measurement of hormone binding in discrete tubule segments, we determined the binding sites of '25I-angiotensin II along the nephron of Sprague-Dawley rats.Specific binding in proximal convoluted tubule (PCT) (at 250C, pH 7.4) was linearly related to tubule length and saturable, with an apparent maximal binding capacity of -300 amol cm-'. Binding specificity was verified in competition experiments that revealed significant (P < 0.001) and comparable competition for radioligand binding by angiotensin II and angiotensin precursor, metabolite, and analogues, whereas unrelated peptides of similar size (bradykinin, ACITH 11-101) were without effect. The profile of specific angiotensin II binding along the nephron was: PCT, 216±13; pars recta, 86±14; medullary thick ascending limb of Henle's loop, 46±8; cortical thick ascending limb of Henle's loop, 77±8; distal convoluted tubule, 49±10; cortical collecting tubule, 15±1; medullary collecting tubule, 32±7 amol cm-'.These results indicate the presence of specific angiotensin II binding sites in all tubule segments studied, but binding capacity was highest in the proximal convoluted tubule, in agreement with transport studies that localize the effects of the hormone in this segment.

Background/Objectives-Previous studies consistently report that diet quality is inversely associated with risk of cardiovascular disease (CVD) and type 2 diabetes. However, few studies have assessed the association of diet quality with serum lipoproteins, an intermediate-marker of cardio-metabolic health, or assessed whether type 2 diabetes modifies these associations. This study assessed associations of diet quality (evaluated using the Alternative Healthy Eating Index (AHEI)), and the interaction of diet quality with diabetes, on total cholesterol (TC), triglycerides (TG), low density lipoprotein (LDL-C), high density lipoprotein (HDL-C), apolipoprotein A (apoA1) and apolipoprotein B (apoB) among American Indians (AIs). Subjects/Methods-Participants comprised AIs who participated in the Strong Heart Family Study (SHFS)-a study of CVD and its risk factors in 12 AI communities. Generalized estimated equations (GEE) were used to examine the: (1) cross-sectional associations of diet quality (as determined by AHEI) with serum lipoproteins (n=2 200); and (2) the prospective associations of the AHEI measured at baseline with serum lipoproteins (n=1 899). Users may view, print, copy, and download text and data-mine the content in such documents, for the purposes of academic research, subject always to the full Conditions of use: