Involvement of nitric oxide and prostacyclin in the antihypertensive effect of low-molecular-weight procyanidin rich grape seed extract in male spontaneously hypertensive rats

Identifier:  imarina:6387693

Handle: https://hdl.handle.net/20.500.11797/imarina6387693

Authors:  Quinones, M; Guerrero, L; Fernandez-Vallinas, S; Pons, Z; Arola, L; Aleixandre, A; Muguerza, B

Abstract:
The aim of this study was to evaluate the involvement of endothelial-relaxing factors as possible antihypertensive mechanism of low-molecular-weight procyanidin rich grape seed extract (LM-GSPE). Thirty 17-20-week-old male spontaneously hypertensive rats (SHR) were administered water or 375. mg/kg LM-GSPE by intragastric gavage. One millilitre of saline, 30. mg/kg NG-Nitro-l-arginine methyl ester (l-NAME) or 5. mg/kg indomethacin was administrated intraperitoneally. Systolic blood pressure (SBP) and diastolic blood pressure (DBP) were recorded before and 6. h after oral administration. Plasma concentration of 6-keto-prostaglandin F1α (PGF1α) was quantified. In addition, we evaluated the relaxation caused by LM-GSPE in different aorta preparations. The antihypertensive effect of LM-GSPE was completely and partially abolished by l-NAME and indomethacin, respectively. In addition, plasma PGF1α was increased in LM-GSPE-administered rats. Finally, LM-GSPE relaxed the intact aorta preparations but did not relax the endothelium-denuded aorta rings. l-NAME inhibited the relaxation caused by LM-GSPE in the SHR aorta rings, but indomethacin did not. Therefore, the antihypertensive effect of LM-GSPE in SHR is endothelium dependent, and it could be mediated by changes in endothelium-derived nitric oxide bioavailability. Nevertheless, prostacyclin could also contribute additionally to this effect. © 2013 Elsevier Ltd.