Research ArticleOrganic Anion Trans

Research Article
Organic Anion Transporter 5 Renal Expression and
Urinary Excretion in Rats with Vascular Calcification
María Herminia Hazelhoff, Romina Paula Bulacio, and Adriana Mónica Torres
Area Farmacolog´ıa, Facultad de Ciencias Bioqu´ımicas y Farmaceuticas, Universidad Nacional de Rosario, CONICET, ´
Suipacha 531, 2000 Rosario, Argentina
Correspondence should be addressed to Adriana Monica Torres; [e-mail] ´
Received 15 April 2013; Revised 25 July 2013; Accepted 29 August 2013
Academic Editor: Marlies Ostermann
Copyright © 2013 Mar´ıa Herminia Hazelhoff et al. This is an open access article distributed under the Creative Commons
Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is
properly cited.
It has been described renal damage in rats with vascular calcification. The organic anion transporter 5 (Oat5) is only expressed in
kidney, and its urinary excretion was proposed as potential early biomarker of renal injury. The aim of this study was to evaluate the
Oat5 renal expression and its urinary excretion in an experimental model of vascular calcification in comparison with traditional
markers of renal injury. Vascular calcification was obtained by the administration of an overdose of vitamin D3 (300,000 IU/kg,
b.w., i.m.) to male Wistar rats. Oat5 urinary abundance was evaluated by Western blotting. Traditional markers of renal injury,
such as creatinine and urea plasma levels, urinary protein levels, and urinary alkaline phosphatase (AP) activity, were determined
using commercial kits. Histology was assessed by hematoxylin/eosin staining. Oat5 renal expression was evaluated by Western
blotting and by immunohistochemistry. An increased expression of Oat5 in renal homogenates, in apical membranes, and in its
urinary excretion was observed in rats with vascular calcification. The traditional parameters used to evaluate renal function were
not modified, with the exception of histology. It is possible to postulate the urinary excretion of Oat5 as a potential noninvasive
biomarker of renal injury associated with vascular calcification.
1. Introduction
Calcium overload in vascular smooth muscle is an active
process which not only progresses with aging but also is
associated with various age-related vascular diseases such as
atherosclerosis, hypertension, and cardiac valve disease [1–3].
An experimental model that produces an increase in arterial
wall calcium content is achieved by the administration of
an overdose of vitamin D3 [4–8]. In this model, calcium
overload is observed in the arterial wall, in the heart, and in
the kidneys leading to the impairment of their function [2].
Morphological and functional alterations were described in
the kidney [5–8].
Organic anion transporters (Oats in animals/OATs in
humans, subfamily of Slc22 drug transporters) mediate transport
of endogenous and exogenous organic anions (OA)
and play a major role in the uptake and/or secretion of OA
in cells of various mammalian organs, mainly in the liver
and in the kidneys. The organic anion transporter type 5
(Oat5, Slc22a19) from rats and mice has been cloned and
characterized as an organic anion/dicarboxylate antiporter
[9–12]. This protein is exclusively expressed in the kidneys
and is located at the brush border membrane of the
proximal tubule straight segment S3, in the outer stripe of
the outer medulla and in the juxtamedullary cortex [10,
12]. It transports dehydroepiandrosterone sulfate, estrone-3-
sulfate, and ochratoxin A [9–12]. Rat Oat5 interacts with

Results (Indonesian) 1:

Penelitian PasalAnion organik Transporter 5 ginjal ekspresi danEkskresi urin pada tikus dengan pengapuran vaskularMaría Herminia Hazelhoff, Romina Paula Bulacio dan Adriana Mónica TorresArea Farmacolog´ıa, Facultad de Ciencias Bioqu´ımicas y Farmaceuticas, Universidad Nacional de Rosario, CONICET ´Suipacha 531, 2000 Rosario, ArgentinaKorespondensi harus ditujukan kepada Adriana Monica Torres; [e-mail] ´Menerima 15 April 2013; Revisi 25 Juli 2013; Diterima 29 Agustus 2013Akademik Editor: Marlies OstermannHak cipta © 2013 Mar´ıa Herminia Hazelhoff et al. Ini adalah artikel akses terbuka yang didistribusikan di bawah Creative CommonsLisensi atribusi, yang memungkinkan penggunaan tak terbatas, distribusi, dan reproduksi dalam media apapun, asalkan karya aslibenar dikutip.Telah dijelaskan kerusakan ginjal pada tikus dengan vaskular pengapuran. Transporter anion organik 5 (Oat5) hanya dinyatakan dalamginjal, dan ekskresi urin yang diusulkan sebagai potensi awal biomarker ginjal cedera. Tujuan dari penelitian ini adalah untuk mengevaluasiOat5 ekspresi ginjal dan ekskresi urin yang dalam model eksperimental vaskular pengapuran dibandingkan dengan tradisionalspidol ginjal cedera. Pengapuran vaskular diperoleh oleh administrasi overdosis vitamin D3 (300.000 IU/kg,BW, i.m.) untuk laki-laki Wistar tikus. Oat5 kemih kelimpahan dievaluasi oleh blotting Barat. Tanda-tanda tradisional ginjal cedera,kreatinin dan kadar plasma urea, kadar protein urin dan aktivitas kemih alkali fosfatase (AP), bertekadmenggunakan kit komersial. Histologi dinilai oleh hematoxylin eosin pewarnaan. Oat5 ginjal ekspresi dievaluasi oleh Baratblotting dan oleh immunohistochemistry. Meningkatkan ekspresi Oat5 dalam homogenates ginjal, di apikal membran, dan dalam nyaekskresi urin diamati pada tikus dengan vaskular pengapuran. Parameter tradisional yang digunakan untuk mengevaluasi fungsi ginjal yangtidak diubah, dengan pengecualian Histologi. Hal ini dimungkinkan untuk dalil ekskresi urin Oat5 sebagai sebuah prospek non-invasifbiomarker ginjal cedera yang berhubungan dengan pembuluh darah pengapuran.1. PendahuluanKalsium yang berlebihan di otot polos vaskular adalah aktifproses yang tidak hanya berlangsung dengan penuaan tetapi jugaterkait dengan berbagai penyakit vaskular yang berkaitan dengan usia sepertiatherosklerosis, hipertensi, dan penyakit katup jantung [1 – 3].Model eksperimental yang menghasilkan peningkatan arterikandungan kalsium dinding dicapai oleh administrasioverdosis vitamin D3 [4 – 8]. Dalam model ini, kalsiumoverload diamati dalam dinding arteri, di jantung dan diginjal mengarah ke penurunan fungsi mereka [2].Perubahan morfologi dan fungsional yang dijelaskan dalamginjal [5 – 8].Pengangkut anion organik (oat di hewan/gandum dimanusia, subfamili Slc22 obat pengangkut) menengahi transportasidari anion organik eksogen dan endogen (OA)dan memainkan peran utama dalam penyerapan dan/atau sekresi OAdalam sel mamalia berbagai organ, terutama di hatidan di ginjal. Transporter anion organik jenis 5(Oat5, Slc22a19) dari tikus dan tikus telah kloning dandicirikan sebagai antiporter anion organik/dicarboxylate[9 – 12]. Protein ini khusus dinyatakan dalam ginjaldan terletak di membran perbatasan sikatlurus segmen tubulus proksimal S3, di luar garis darimedula luar dan dalam korteks juxtamedullary [10,12]. ia mengangkut dehydroepiandrosterone sulfat, estrone-3 -sulfat, dan ochratoxin [9 – 12]. Oat5 tikus berinteraksi dengan