PT  - JOURNAL ARTICLE
AU  - Shigeki Tazawa
AU  - Tokio Nakane
AU  - Shigetoshi Chiba
TI  - Angiotensin II Type 1 Receptor Blockade Prevents Up-Regulation of Angiotensin II Type 1A Receptors in Rat Injured Artery
DP  - 1999 Feb 01
TA  - Journal of Pharmacology and Experimental Therapeutics
PG  - 898--904
VI  - 288
IP  - 2
4099  - http://jpet.aspetjournals.org/content/288/2/898.short
4100  - http://jpet.aspetjournals.org/content/288/2/898.full
SO  - J Pharmacol Exp Ther1999 Feb 01; 288
AB  - We investigated the effects of the angiotensin II (Ang II) type 1 receptor (AT1) antagonist KRH-594 on levels of the mRNAs for AT1A, AT1B, platelet-derived growth factor-receptor β (PDGF-Rβ), and extracellular matrix (ECM)-related genes using the competitive reverse transcription-polymerase chain reaction (RT-PCR) method and on neointimal formation in the balloon-injured rat carotid artery. The mRNA levels for AT1A and PDGF-Rβ, but not for AT1B, increased from day 3 after injury to day 14. KRH-594 administered orally at 3 and 10 mg/kg/day significantly suppressed these increases. KRH-594 (10 mg/kg/day) also suppressed the injury-induced gene expressions for transforming growth factor-β1 and fibronectin and reduced collagen α1(I) and α1(III) mRNA levels for the first 7 days after injury. KRH-594 (10 and 30 mg/kg/day) significantly and dose-dependently reduced the neointimal area in cross sections of the artery 14 days after injury. Another AT1 antagonist, TCV-116 (candesartan cilexetil; 1 and 3 mg/kg/day p.o.), had similar effects on the morphological change and AT1A mRNA level, whereas a smooth muscle relaxant, hydralazine (10 mg/kg/day p.o.), did not. These results indicate that up-regulation of AT1A, PDGF-Rβ, and ECM-related genes in the balloon-injured carotid artery is in part an AT1-mediated phenomenon and that prevention of receptor up-regulation may contribute to the attenuating effects of AT1 antagonists on neointimal formation after injury. The American Society for Pharmacology and Experimental Therapeutics