TY - JOUR
T1 - Renal AT1 receptor
T2 - Autoradiographic localization and quantification in rat
AU - Asano, Naoko
AU - Ogura, Toshio
AU - Mimura, Yukari
AU - Kishida, Masayuki
AU - Kataoka, Hideo
AU - Otsuka, Fumio
AU - Yamauchi, Takayoshi
AU - Makino, Hirofumi
PY - 1998/5/1
Y1 - 1998/5/1
N2 - To elucidate the precise localization of angiotensin II (Ang II) type 1 (AT1) receptors in the kidney, we utilized in vitro macro- and micro- autoradiography (ARG) of [3H]-Ang II bindings to the Wistar rat kidney in the presence of L-158,809, a specific non-peptide AT1 receptor antagonist. Besides, we estimated the density of renal AT1 receptors using the quantification of macro-ARG. The density of [3H]-Ang II binding to renal tissue was concentration-dependent in both renal cortex and medulla. Although the addition with 500 nM arginine vasopressin and 500 nM atrial natriuretic peptide had no effect on [3H]-Ang II, the total binding of [3H] Ang II completely displaced by the addition with 500 nM unlabeled Ang II or L- 158,809. Macro-ARG revealed that the amount of both Ang II and AT, receptors in the renal medulla greatly exceeded those in the renal cortex. In the medulla, the density of these receptors was not localized on the outer medulla but was confirmed mainly to the inner medulla, especially to the inner zone and longitudinal bands. Since the density and localization of AT1 receptors was consistent with that of total Ang II receptors, it appears that AT1 receptors comprise most of the Ang II receptors in the kidney. Micro- ARG revealed that Ang II receptors were mainly located in the glomerulus and proximal tubules of the renal cortex, as well as on the circumferences of vessels and the vasa recta of the renal medulla. The present study established a method for ARG of AT1 receptors in the kidney as well as a method for quantifying the macro-ARG.
AB - To elucidate the precise localization of angiotensin II (Ang II) type 1 (AT1) receptors in the kidney, we utilized in vitro macro- and micro- autoradiography (ARG) of [3H]-Ang II bindings to the Wistar rat kidney in the presence of L-158,809, a specific non-peptide AT1 receptor antagonist. Besides, we estimated the density of renal AT1 receptors using the quantification of macro-ARG. The density of [3H]-Ang II binding to renal tissue was concentration-dependent in both renal cortex and medulla. Although the addition with 500 nM arginine vasopressin and 500 nM atrial natriuretic peptide had no effect on [3H]-Ang II, the total binding of [3H] Ang II completely displaced by the addition with 500 nM unlabeled Ang II or L- 158,809. Macro-ARG revealed that the amount of both Ang II and AT, receptors in the renal medulla greatly exceeded those in the renal cortex. In the medulla, the density of these receptors was not localized on the outer medulla but was confirmed mainly to the inner medulla, especially to the inner zone and longitudinal bands. Since the density and localization of AT1 receptors was consistent with that of total Ang II receptors, it appears that AT1 receptors comprise most of the Ang II receptors in the kidney. Micro- ARG revealed that Ang II receptors were mainly located in the glomerulus and proximal tubules of the renal cortex, as well as on the circumferences of vessels and the vasa recta of the renal medulla. The present study established a method for ARG of AT1 receptors in the kidney as well as a method for quantifying the macro-ARG.
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M3 - Article
C2 - 9667070
AN - SCOPUS:0031595026
SN - 1078-0297
VL - 100
SP - 161
EP - 170
JO - Research Communications in Molecular Pathology and Pharmacology
JF - Research Communications in Molecular Pathology and Pharmacology
IS - 2
ER -