Restoration of arterial baroreflex function contributes to organ protection in spontaneously hypertensive rats treated with long- term hydrochlorothiazide mixture

Hydrochlorothiazide m ixture(HCTM) is widely used in China for the treatment of hypertension.This mix- ture consists of hydrochlorothiazide,triamterene,reserpine,hydralazine and chlordiazpoxide,with small(one- third to one- fifth of normal) doses of each drug.The present study was designed to investigate the effects of this mixture on blood pres- sure,blood pressure variability(BPV) ,baroreflex sensitivity(BRS) and end- organ damage in spontaneously hypertensive rats(SHR) .The HCTM was m ixed in the ratchow and rats were treated for4 months.After treatm ent,rats were catheter- ized and their blood pressure,BPV and BRS were m easured in the conscious state.Organ damage was exam ined after these measurements had been completed.It was found that HCTM not only decreased blood pressure and BPV,but also ameliorat- ed im paired BRS in SHR.The HCTM had an obvious effect on organ protection in SHR.The HCTM prevented leftventricu- lar hypertrophy and this effect was mainly related to a decrease in systolic blood pressure.The effects of HCTM on prevent- ing renal atrophy were mainly determ ined by BRS.Baroreflex sensitivity was the most im portant determinant for predicting organ damage in HCTM- treated SHR.In conclusion,long- term treatment of rats with HCTM prevented hypertensive organ damage.Restoration of arterial baroreflex function contributes to organ protection in SHR treated in the long term with HCTM.