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Effect of Angiotensin 2 Type 1 Receptor Blocker in Autonomic Nerve Regulatory System in Rats
Author(s) -
Yajima Yoshiharu
Publication year - 2010
Publication title -
the faseb journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.709
H-Index - 277
eISSN - 1530-6860
pISSN - 0892-6638
DOI - 10.1096/fasebj.24.1_supplement.808.8
Subject(s) - blood pressure , medicine , rostral ventrolateral medulla , vasoconstriction , sodium nitroprusside , endocrinology , renin–angiotensin system , angiotensin ii , baroreflex , angiotensin receptor , phenylephrine , heart rate , nitric oxide
It was well established that the renin‐angiotensin systems play important role in the cardiovascular regulatory system. Especially, Angiotensin 2 type 1 receptor (AT1R) leads to elevated blood pressure through vasoconstriction and increasing sympathetic drive. Therefore, anti‐hypertensive drug, AT1R blocker (ARB), has been realized that beneficial effect in hypertensive subjects. However, several evidences suggest that these drugs have beneficial effects not only by anti‐hypertensive effects but also organ protective effect by modulate autonomic nerve activity. In this study, we hypothesized that small dose of ARB, that is not effect to blood pressure reduction, can be effect to modulate autonomic nerve activity. Rats were treated with RNH‐6270 (the active form of olmesartan medoxomil), an ARB, for 2 weeks (0.4mg/kg/day in drinking water). After treatment, animals measured arterial pressure by femoral artery and cardiovascular response for Phenylephrine, sodium nitroprusside and glutamatergic stimulation of Rostral ventrolaterall medulla (RVLM). Even though, it's basal arterial pressure and the cardiovascular response to those stimulation was no significantly different with control animals, para‐sympathetic nerve index (high frequency (0.74–2.0 Hz) component in pulse interval fluctuation (PI‐HF)) were significantly increased in treated animals. These results suggest that small dose of ARB can effect on autonomic nerve activity, which may support a beneficial effect on cardiovascular regulatory system.