Constructive effect of exogenous melatonin against osteoporosis after ovariectomy in rats

• Published in: Analytical and quantitative cytology and histology Vol. 29; no. 5; p. 317
• Main Authors: Uslu, Serap, Uysal, Ayşegül, Oktem, Gülperi, Yurtseven, Mine, Tanyalçin, Tijen, Başdemir, Gülçin
• Format: Journal Article
• Language: English
• Published: United States 01-10-2007
• Subjects: Animals; Bone Density; Female; Lumbar Vertebrae - drug effects; Lumbar Vertebrae - pathology; Melatonin - therapeutic use; Osteoporosis - drug therapy; Ovariectomy; Rats; Rats, Wistar
• ISSN: 0884-6812

To analyze histomorphometric, densitometric and biochemical effects of melatonin on osteoporosis in ovariectomized rats.
Wistar rats were divided into 6 groups. Group C: control; Group I: bilateral ovariectomy (OVX); Group II: OVX + vehicle; Group III: OVX + 10 mg/kg/day melatonin (MLT); Group IV: OVX + 30 mg/kg/day MLT; Group V: sham + 10 mg/kg/day MLT. Cortex, trabecula, osteoblast and osteoclast numbers were evaluated on vertebra and femur histomorphometrically. Hydroxyproline analysis was used to determine collagen content of femur and vertebrae. Bone mineral density and bone mineral content were measured.
Trabecular thickness and trabecular area of vertebra and femur and cortical thickness of femur showed remarkable decrease after OVX, but increased after MLT treatment in the OVX+MLT groups. Following OVX, no statistically significant difference was found in number of osteoblasts or osteoclasts, trabecular number or levels of hydroxyproline after treatment with MLT. OVX caused significant decrease in bone mineral density, but treatment with MLT was unable to reverse this effect.
MLT may trigger microscopic changes in bone, and time of application is critical for clinical recovery. It can be effective in helping treat postmenopausal osteoporosis. However, it is contraindicated in women who have normal-functioning ovaries.