L-arginine supplementation reduces blood pressure and plasma lipid levels in an animal model of perimenopause induced by 4-Vinylcyclohexene diepoxide

Document Type : Original Article

Authors

1 Physiology/Basic Medical Sciences/University of Lagos/Lagos/Nigeria

2 Pharmacology, Therapeutics & Toxicology/Faculty of Basic Medical Sciences/ University Of Lagos/Lagos/Nigeria

3 Clinical Pathology/ Faculty of Clinical Sciences/University of Lagos/Lagos/Nigeria

4 Physiology/Faculty of Basic Medical Sciences/University of Lagos/Lagos/Nigeria

5 Physiology/Faculty of Basic Medical Sciences/ Lagos State University/Lagos/Nigeria

6 Morphology, Physiology and Basic Pathology/Faculdade de Odontologia/University of São Paulo/Ribeirao Preto/Brazil

Abstract

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.

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