The incidence of women developing high blood pressure during perimenopause has been documented and is sustained till menopause. However, no study till date on beneficial effects of L-arginine supplementation on BP during perimenopause in humans and animal models of perimenopause.

Female rats 28 days old were divided into 3 groups; Control group was injected (SC) daily with Corn oil (2.5 μl/g BW) for 15 days, allowed to grow till 12th week; VCD group was injected (SC) daily with 4-vinylcyclohexene diepoxide (160 mg/kg BW) diluted in Corn oil (2.5 μl/g BW) for 15 days, allowed to grow till 12th week; VCD + L-ARG group was injected as VCD group, allowed to grow till 8th week, then administered oral 100mg/kg L-arginine daily for additional 4 weeks. Caudal BP was measured with tail-cuff apparatus (Kent Scientific CODA system) at weeks eight, ten, and twelve. Terminal BP was also measured with a power-lab apparatus and blood samples were subsequently collected for measurement of plasma lipid profile.

L-arginine supplementation significantly reduced systolic, diastolic and mean arterial BP parameters in the VCD + L-ARG group compared to the Control and VCD groups (P < 0.05). It also significantly reduced total cholesterol and LDL concentrations in the VCD + L-ARG group compared to the Control and VCD groups (P < 0.05). HDL concentration was significantly higher in the VCD and VCD + L-ARG groups compared to the Control group (P < 0.05). These results show that L-arginine supplementation ameliorates some cardiovascular risk factors during perimenopausal transitory period.