Teriparatide and exercise improve bone, skeletal muscle, and fat parameters in ovariectomized and tail-suspended rats.

Abstract

Although teriparatide (TPTD) and exercise may improve osteoporosis, muscle atrophy, and fat metabolism during ageing, the effects of treatment with a combination of TPTD and exercise on these factors remain unclear. Therefore, this study examined the effects of TPTD and exercise on bone, skeletal muscle, and fat in ovariectomized and tail-suspended rats. Seven-month-old female Wistar rats were ovariectomized and subjected to tail suspension. The rats were then randomized into one of the following four groups (n = 20/group) after 4weeks: control group, treated with TPTD vehicle and no exercise; TPTD group (30µg/kg TPTD, 3days/week); Exercise group (treadmill at 12m/min, 60min/day, 5days/week); and Combined group treated with TPTD and treadmill exercise. After 1 and 8weeks of treatment, bone, skeletal muscle, and fat tissue parameters were evaluated. TPTD improved bone mineral density (BMD), bone structure, bone strength at the femoral metaphysis, and the percentage of skeletal muscle mass, and decreased the percentage of fat mass and the adipose volume in the bone marrow. Treadmill exercise increased BMD, bone strength of cancellous bone, and the percentage of skeletal muscle mass, and decreased the percentage of fat mass as seen on dual-energy X-ray absorptiometry. Furthermore, combined treatment significantly affected BMD, bone structure, and bone strength of cortical bone at the femoral diaphysis. TPTD or treadmill exercise improved bone, skeletal muscle, and fat mass. Combination therapy with TPTD and exercise had synergistic effects on BMD, structure, and bone strength in ovariectomized, tail-suspended rats.