Specific receptor for angiotensinogen on human renal cells.

Autor: Pan N; Marshfield Clinic Research Foundation, 1000 North Oak Avenue, Marshfield, WI 54449, USA., Luo J, Kaiser SJ, Frome WL, Dart RA, Tewksbury DA
Jazyk: angličtina
Zdroj: Clinica chimica acta; international journal of clinical chemistry [Clin Chim Acta] 2006 Nov; Vol. 373 (1-2), pp. 32-6. Date of Electronic Publication: 2006 Jun 09.
DOI: 10.1016/j.cca.2006.04.021
Abstrakt: Background: We recently demonstrated the existence of an angiotensinogen (AGT) receptor on placental cells. It has been established that there is a tissue-specific renin-angiotensin system (RAS) in the human kidney. This study focused on whether human renal proximal tubule epithelial cells possessed an AGT receptor.
Methods: Human renal proximal tubule epithelial cells were cultured in plastic wells. Binding assays were carried out by adding iodinated angiotensinogen ((125)I-AGT) to each culture well, with or without unlabeled AGT. The cells were washed, lysed, and the radioactivity was measured.
Results: Human renal proximal tubule epithelial cells bound (125)I-AGT in a time-dependent manner. This binding was competitively and specifically inhibited by unlabeled AGT. Bound (125)I-AGT was competitively displaced by AGT. Acid washing removed 30% at 8 h, indicating that 70% bound AGT had been internalized. Scatchard plot binding analysis showed that the identified AGT receptor possessed a single class of high-affinity binding sites (K(d)=1.73 nmol, B(max)=23.39 pmol/10(6) cells).
Conclusion: The results of this study provide evidence for the presence of an AGT receptor on human renal proximal tubule epithelial cells. Our finding suggests that the AGT receptor may be an integral component of the renal RAS.
Databáze: MEDLINE
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