THE STRESS-INDUCED BONE RESORBTION IN RAT IN OPEN FIELD
Background. Osteoporosis and osteomalacia are insensibly diseases, therefore assessment of risk factors is significant for their diagnosis, prophylaxis and treatment. Now the depression is considered as factor of osteoporosis, but emotional stress is not related to risk factors of system bone diseases. Pathogenesis of osteoporosis during depression isn’t full studied. Objective - investigate the stress-induced bone resorption in rat in open field. Design and methods. The study was realized on both male and female white outbred rats. Rats were placed in open field for 3, 30 and 60 minutes. Rat behavior, functional activity of stress-releasing systems, bone metabolism and weight related parameters stress-sensitivity organs and femur was measured. Results. Placement in open field had no effect on weight related parameters stress-sensitivity organs and femur. The function activity of stress systems, calcium and free hydroxyproline blood levels in rats were increased during 3 minutes in open field. At this time histological changes on pelvic bone slice were not observed. Over 30 and 60 minutes in open field hydroxyproline blood level was normalized, but calcium blood level was elevated and the osteocytic osteolysis traces were observed on pelvic bone slice. Stress-induced bone resorption was associated with higher grooming in rat behavior. Conclusion. Bone resorption develop during first 3 minutes of emotional stress and provided by osteocytic osteolysis mechanism during at the least one hour.