Enhanced diurnal variations of cardiac renin-angiotensin system in hypertensive rats

Abstract

Abstract: AIM: To investigate whether the circadian mRNA expression of the renin-angiotensin system (RAS) components (ATNG 、AT1R、AT2R) in myocardium is correlated with left ventricular hypertrophy in both spontaneously hypertensive rats (SHR) and renal hypertensive rats (RHR).METHODS: The model of RHR as established using 2K1C (two-kidney one clip).SHR, RHR, and normotensive control rats (CON) were oused in a separate environment-controlled room for two eeks, in which a strict 12-hour light 12-hour dark cycle egimen was enforced (lights on at 9 ∶00, zeitgeber time ZT0]).Rats were killed every 4 hours from 9 ∶00 am ZT0) to 5 ∶00 pm (ZT20) on three separate days.We xamined the circadian mRNA expression of ATNG 、AT1 R、AT2R in the hearts of SHR, RHR and CON rats by T-PCR.RESULTS: Heart weight to body weight ratios nd left ventricle weight to heart weight ratios indicated a ignificant increase in SHR and RHR compared with normotensive ats.The cardiac mRNA expression of the RAS omponents showed circadian oscillations in SHR, RHR nd CON rats.The amplitudes of these circadian fluctuations ere greater in the SHR and RHR than in the CON ats.The mRNA levels of the RAS components were increased n the SHR and RHR compared with the CON rats t many time points.CONCLUSION: The data indicate hat overexpression and enhanced amplitudes of circadian luctuations of RAS components in SHR and RHR may ay a role in the development of left ventricular hypertrophy.

Key words: hypertrophic myocardium, renin-angiotensin ystem, circadian rhythm

CLC Number:

R965.2
R966

HUANG Jian-zhai, WEI Li, WANG Xiao-jun, LI Qing-ping. Enhanced diurnal variations of cardiac renin-angiotensin system in hypertensive rats[J]. Chinese Journal of Clinical Pharmacology and Therapeutics, 2006, 11(8): 863-867.

References

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