The potential effect of vitamin D against bone loss and vascular calcification in ovariectomized rats: possible association with serum nitric oxide.

Abstract

Many epidemiological studies have shown an association between osteoporosis and peripheral vascular disease in postmenopausal women. This work was provided to investigate the possible effect of vitamin D against postmenopausal bone loss and vascular calcification in adult rats. This study was carried on 24 Sprague Dawley female rats. Rats were divided into four main groups (6 rats for each group). Group I : control sham-operated rats. Group II : sham operated rats treated with vitamin D . Group III : control ovariectomized (OVX) rats. Group IV : OVX rats treated with vitamin D. Ovariectomized rats were injected intraperitoneal with active vitamin D (calcitriol) 3 times a week for one month in the form of 0.04 μg/kg calcitriol. Serum level of estradiol, calcium, phosphorus and osteoblastic markers (alkaline phosphatase and osteocalcin) were measured. Serum levels of lipid profile, parathormone and nitric oxide were also evaluated. The bone and the aortic wall were prepared for histopathological study. In comparisons to the ovariectomized rats, active vitamin D caused significant attenuation of the bone loss, biomechanical fragility and delayed the onset of vascular calcification in the aortic wall. Also it improved the lipid profile, serum nitric oxide levels and suppressed parathyroid hormone level. This work suggests that the administration of vitamin D has a beneficial effect on the bone quality and also on delaying the onset of aortic vascular calcification in ovariectomized rats. And suggests a possible association with serum nitric oxide.