Progressive isometric force training and bone mass in rats.

In ten growing male Wistar rats, isometric strength training for 69 days (3-6 times vertical gripping position on a wire-netting during 2 x 30 s, with progressive loading of the tail through a 50-200 g indwelling clip), fat mass and plasma leptin concentrations were lower on day 70 than in ten sedentary controls. Muscle mass and femoral trabecular and cortical bone mineral density were simultaneously higher in exercised animals than in controls. Such an effect might result from decreased bone resorption.

Bone mass in obese diabetic Zucker rats: influence of treadmill running.

Some controversy exists in the literature concerning bone mineral densitry (BMD) in obese, diabetic, leptin-resistant Zucker rats. To investigate this question further, we measured body composition and femoral bone mineral density (BMD) (by dual energy X-ray absorptiometry) in 10 male and 10 female 6 month-old Zucker rats and their homozygous lean controls. Fat mass (percent from body weight) was about 3 times higher in fatty rats than in lean controls.

Amylin and bone metabolism in streptozotocin-induced diabetic rats.

Amylin (AMY) is a 37 amino acid peptide cosecreted with insulin (INS) by pancreatic beta-cells and absent in type 1 diabetes, a condition frequently associated with osteopenia. AMY binds to calcitonin receptors, lowers plasma calcium concentration, inhibits osteoclast activity, and stimulates osteoblasts. In the present study, we examined the effects of AMY replacement on bone loss in a streptozotocin (STZ)-induced rodent model type 1 diabetes.

Rutin inhibits ovariectomy-induced osteopenia in rats.

Several studies suggest that polyphenols might exert a protective effect against osteopenia. The present experiment was conducted to observe the effects of rutin (quercetin-3-O-glucose rhamnose) on bone metabolism in ovariectomized (OVX) rats. Thirty 3-month-old Wistar rats were used.

Amylin inhibits ovariectomy-induced bone loss in rats.

Amylin (AMY), a peptide co-secreted with insulin by pancreatic beta-cells, inhibits bone resorption and stimulates osteoblastic activity. The ovariectomized (OVX) rat is an established animal model for human osteoporosis. Thus, the present experiment was performed to study the effects of AMY on estrogen deficiency-induced bone loss in rats.