The protective effects of ginsenoside Rg1 against hypertension target-organ damage in spontaneously hypertensive rats

Blood pressure variability (BPV) is associated with the development and progression of severe target organ damage (TOD). This study aims to evaluate the protective effect of paeoniflorin enriched extract from Radix Paeoniae Alba (PG) on BPV and TOD in spontaneously hypertensive rats (SHR). All SHR were orally treated with distilled water, metoprolol (MP, 20 mg/kg), and PG (PG-H, 90 mg/kg or PG-L, 30 mg/kg) for a single time or daily for 7 weeks. The 24-hour dynamic blood pressure was monitored and then calculated BPV including long- and short-term systolic blood pressure variability (SBPV), diastolic blood pressure variability (DBPV), mean blood pressure variability (MBPV), and heart rate variability (HRV) as well as the 24-hour-SBP, 24-hour-DBP, and 24-hour-MBP. The protective effects of PG on TOD were observed by histopathologic and biochemical detection. The results indicated that long- and short-term SBPV, DBPV, MBPV, and HRV as well as 24-hour-SBP, 24-hour-DBP, and 24-hour-MBP showed no significant changes after single-dose administration of PG and significantly decreased after administration with PG for 7 weeks. PG could also markedly improve the damage of aorta, heart, kidney, and brain. This study suggested that PG could notably reduce BPV, stabilize blood pressure, and mitigate TOD in SHR.

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Angiotensin-(1–7) prevents development of severe hypertension and end-organ damage in spontaneously hypertensive rats treated with l-NAME

AJP Heart and Circulatory Physiology ◽

10.1152/ajpheart.00632.2005 ◽

2006 ◽

Vol 290 (2) ◽

pp. H684-H691 ◽

Cited By ~ 137

Author(s):

Ibrahim F. Benter ◽

Mariam H. M. Yousif ◽

J. T. Anim ◽

C. Cojocel ◽

D. I. Diz

Keyword(s):

Nitric Oxide ◽

Spontaneously Hypertensive Rats ◽

Severe Hypertension ◽

Organ Damage ◽

Left Ventricular ◽

Protective Effects ◽

Additive Effects ◽

Hypertensive Rats ◽

Spontaneously Hypertensive ◽

End Organ Damage

We examined the influence of chronic treatment with ANG-(1–7) on development of hypertension and end-organ damage in spontaneously hypertensive rats (SHR) chronically treated with the nitric oxide synthesis inhibitor l-NAME (SHR-l-NAME). l-NAME administered orally (80 mg/l) for 4 wk significantly elevated mean arterial pressure (MAP) compared with SHR controls drinking regular water (269 ± 10 vs. 196 ± 6 mmHg). ANG-(1–7) (24 μg·kg−1·h−1) or captopril (300 mg/l) significantly attenuated the elevation in MAP due to l-NAME (213 ± 7 and 228 ± 8 mmHg, respectively), and ANG-(1–7) + captopril completely reversed the l-NAME-dependent increase in MAP (193 ± 5 mmHg). l-NAME-induced increases in urinary protein were significantly lower in ANG-(1–7)-treated animals (226 ± 6 vs. 145 ± 12 mg/day). Captopril was more effective (96 ± 12 mg/day), and there was no additional effect of captopril + ANG-(1–7) (87 ± 5 mg/day). The abnormal vascular responsiveness to endothelin-1, carbachol, and sodium nitroprusside in perfused mesenteric vascular bed of SHR-l-NAME was improved by ANG-(1–7) or captopril, with no additive effect of ANG-(1–7) + captopril. In isolated perfused hearts, recovery of left ventricular function from 40 min of global ischemia was significantly better in ANG-(1–7)- or captopril-treated SHR-l-NAME, with additive effects of combined treatment. The beneficial effects of ANG-(1–7) on MAP and cardiac function were inhibited when indomethacin was administered with ANG-(1–7), but indomethacin did not reverse the protective effects on proteinuria or vascular reactivity. The protective effects of the ANG-(1–7) analog AVE-0991 were qualitatively comparable to those of ANG-(1–7) but were not improved over those of captopril alone. Thus, during reduced nitric oxide availability, ANG-(1–7) attenuates development of severe hypertension and end-organ damage; prostaglandins participate in the MAP-lowering and cardioprotective effects of ANG-(1–7); and additive effects of captopril + ANG-(1–7) on MAP, but not proteinuria or endothelial function, suggest common, as well as different, mechanisms of action for the two treatments. Together, the results provide further evidence of a role for ANG-(1–7) in protective effects of angiotensin-converting enzyme inhibition and suggest dissociation of factors influencing MAP and those influencing end-organ damage.

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