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ANGIOTENSIN II RECEPTORS IN CARDIAC LEFT VENTRICLES OF DAHL RATS
Author(s) -
Sumida Yoichi,
Umemura Satoshi,
Kobayashi Shunichi,
Kihara Minoru,
Tamura Kouichi,
Ishigami Tomoaki,
Ochiai Hisao,
Chiba Eiko,
Nyui Nobuo,
Ishii Masao
Publication year - 1998
Publication title -
clinical and experimental pharmacology and physiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.752
H-Index - 103
eISSN - 1440-1681
pISSN - 0305-1870
DOI - 10.1111/j.1440-1681.1998.t01-16-.x
Subject(s) - medicine , endocrinology , angiotensin ii receptor type 1 , angiotensin ii , receptor , ventricle , renin–angiotensin system , blood pressure , angiotensin receptor , renovascular hypertension , left ventricular hypertrophy , losartan , chemistry
1. Dahl Iwai salt‐sensitive (DS) rats have been reported as becoming hypertensive with left ventricular hypertrophy (LVH) and heart failure when on a high‐salt diet. Their circulating renin–angiotensin system (RAS) has been reported to be suppressed. To evaluate the role of angiotensin II (AngII) type 1 and type 2 receptors (AT 1 and AT 2 , respectively) in LVH, we compared cardiac AT 1 and AT 2 receptors in 10‐week‐old DS rats and Dahl Iwai salt‐resistant (DR) rats. 2. Seven pairs of 6‐week‐old male DS and DR rats were fed either a low‐ or high‐salt diet (0.3 or 8% NaCl, respectively) for 4 weeks. Left ventricular AngII receptors were measured by radioligand binding assays using [ 125 I]‐[Sar 1 ,Ile 8 ]‐AngII in plasma membrane fractions from these four groups. The AT 1 and AT 2 receptors were distinguished using their specific antagonists CV 11974 and PD 123319, respectively. 3. The high‐salt diet increased blood pressure and the left ventricle:bodyweight ratio in DS rats. However, neither B max for AT 1 and AT 2 receptors nor K d for [ 125 I]‐[Sar 1 ,Ile 8 ]‐AngII differed between the groups. These results are different from those of other reports of pressure‐overload LVH, such as spontaneously hypertensive rats or renovascular hypertension rats, in which AT 1 and AT 2 receptors were reported to be up‐regulated.