Involvement of (pro)renin receptor in the glomerular filtration barrier

(Pro)renin receptor-bound prorenin not only causes the generation of angiotensin II via the nonproteolytic activation of prorenin, it also activates the receptor’s own intracellular signaling pathways independent of the generated angiotensin II. Within the kidneys, the (pro)renin receptor is not only present in the glomerular mesangium, it is also abundant in podocytes, which play an important role in the maintenance of the glomerular filtration barrier. Recent in vivo studies have demonstrated that the overexpression of the (pro)renin receptor to a degree similar to that observed in hypertensive rat kidneys leads to slowly progressive nephropathy with proteinuria. In addition, the handle region peptide, which acts as a decoy peptide and competitively inhibits the binding of prorenin to the receptor, is more beneficial than an angiotensin-converting enzyme inhibitor with regard to alleviating proteinuria and glomerulosclerosis in experimental animal models of diabetes and essential hypertension. Thus, the (pro)renin receptor may be upregulated in podocytes under hypertensive conditions and may contribute to the breakdown of the glomerular filtration barrier

Modulation of renal function indices of the occupationally lead exposed Bangladeshi automobile workers

ABSTRACT Objectives This study aims to compare serum uric acid (SUr) and renal function indices such as serum urea (SU), blood urea nitrogen (BUN), creatinine (SCr), urinary creatinine (UCr) and glomerular filtration rate (GFR) of the lead exposed automobile workers with healthy controls and evaluates association of serum lead (Pb-S) with renal function. Methods Of the total 70 male individuals included in this study, 45 were automobile workers and 25 were age and BMI matched healthy controls. For all the participants, levels of serum lead and their renal function indices were measured using standard assay methods. Results Automobile workers (n=45) had significantly higher (p=0.001) level of Pb-S (40.5±11.2 µg/dL) compared to age and BMI matched healthy controls (n=25, 29.7±10.1 µg/dL). Workers had lower levels of SU, SCr, BUN and UCr (p<0.01) but higher GFR (p=0.117) than controls. Both groups had similar levels of SUr (6.6±1.9 vs 6.9±1.1 mg/dL, respectively). Pb-S in workers demonstrated no relationship with any of the individual renal function indices. Linear regression analysis showed a positive relation of Pb-S of the workers with SCr and GFR, while BMI was negatively correlated. SUr showed a positive correlation with SCr and GFR in the workers while control subjects did not. Conclusion These data indicated modulation of renal function indices among the occupationally lead exposed Bangladeshi automobile workers