Structural features of long bones regeneration in rats with experimental chronic hyperglycemia

Abstract

Objective – to find out the histological, ultramicroscopic and histomorphometric features of regenerative process of long tubular bones in rats with experimental chronic hyperglycemia (CH).Material and methods. The study was performed on 60 white laboratory male rats, which were divided into following groups: I – control group (20 rats); ІІ – group for assessment of glucose homeostasis and simulated CH confirmation (10 rats); III – group for comparison with group II (10 rats); IV – animals with CH and post-traumatic bone defect (20 rats). CH in I and IV groups was simulated by 10% aqueous fructose solution (loading during two weeks) followed by a single injection of streptozotocin (40 mg/kg) and nicotinic acid (1 mg/kg). Animals of I and IV groups were removed from the experiment on the 21st day after injury. Light microscopy was performed using Olympus BH-2 microscope; scanning microscopy – using the electron microscope SEM 102.Results. On the 21st day after reproduction of the injury in rats, the defect site of control rats was mostly filled with formed bone trabecula. At this time in the group with simulated CH only the initial formation of thin fine-meshed bone trabeculae occurred. Single groups of chondrogenic cells were observed around the osteoid beams. In addition, fat cells and lymphocyte-leukocyte infiltration were present in the regenerate. In control group the area of woven bone tissue was 29.26 % larger, and the area of connective tissue was 10.87 % smaller than in CH animals. Also the regenerate of CH rats contained granulation and cartilaginous tissues.Conclusion. Chronic hyperglycemia leads to delayed restorative osteogenesis and impairment of proliferation and differentiation of osteoblastic differon towards the formation of fibrocartilage regenerate.