Supplementation of antihypertensive drug regimen with vitamin E ameliorates alterations of primary haemodynamic parameters and total antioxidant capacity in ovariectomised rats

OBJECTIVES

Ovariectomy induces heightened response to vasoconstrictors, alters vasorelaxation and consequently causes hypertension due to increased oxidative stress in rats.

METHODS

This study evaluated the ameliorative effects of ramipril and vitamin E, on primary haemodynamic parameters and cardiac antioxidant defence status, in ovariectomised rats using 64 adult female rats of the Wistar strain randomly divided as follows: Control (sham); Ovariectomised (OVX); OVX plus Ramipril; OVX plus vitamin E; and OVX plus Ramipril plus vitamin E.

RESULTS

The plasma level of oestrogen was significantly lower (p<0.05), in the ovariectomised rats compared with the sham. The systolic, diastolic and mean arterial blood pressure of ovariectomised rats increased significantly (p<0.05), but the alteration was significantly reduced by the administration of ramipril alone or in combination with vitamin E. Significant decrease (p<0.05) was observed in the serum level of nitric oxide in OVX group compared with Sham. Also, analysed markers of oxidative stress: Malondialdehyde (MDA) contents and hydrogen peroxide (H2O2) generated decreased significantly (p<0.05), but systemic antioxidants: reduced glutathione (GSH) contents; glutathione peroxidase (GPx) and superoxide dismutase (SOD) activities increased significantly (p<0.05) in the ovariectomised rats treated with ramipril and vitamin E compared with untreated ovariectomised rats. The study concludes that alteration, in the primary haemodynamic parameters, associated with ovariectomy in rats is potently ameliorated by co-administration of the antihypertensive drug ramipril and vitamin E.

CONCLUSIONS

The supplementation of antihypertensive regimen with antioxidants such as vitamin E in the treatment of hypertension is therefore justifiable especially in ovariectomised or hypogonadal patients.