Effect of calcitonin on lipid peroxidation in ovariectomized rats

Calcitonin is one of the active substances which is recently used effectively in osteoporosis treatment. In literature there is no information whether calcitonin cause oxidative stress or not. In this study, subcutaneous calcitonin is applied to rats having experimental postmenopausal osteoporosis and the effects of calcitonin on lipid peroxidation and antioxidant system were investigated. Forty-five healthy adult female Swiss albino Wistar rats were used in this study. The rats were divided into three equal groups as control, ovariectomized (Ovx) and ovariectomized+calcitonin (Ovx-CAL). The rats in Ovx and Ovx-CAL were anaesthetized and underwent a bilateral ovariectomy via ventral incision. Ten weeks after ovariectomy, salmon calcitonin (2 IU/kg body weight) was administered via s.c. at a volume of 1 mL per week for 12 weeks to the Ovx-CAL group. At the end of the drug treatment, livers and kidneys of rats were removed and malondialdehyde (MDA) levels and catalase (CAT) activities were determined by biochemical analysis methods. Data were analyzed by one-way ANOVA followed by the post-hoc LSD multiple test. The liver and kidney MDA levels were increased whereas the activity of CAT enzyme was decreased as a result of ovariectomy compared to values in the control group. Similar results were observed in Ovx-CAL group; however, the decline in the CAT activity in the kidney was not significant. In conclusion, we may suggest that calcitonin treatment increases the oxidative stress in osteoporotic rats