Influência da oxigenação hiperbárica nas propriedades mecânicas e estruturais da matriz óssea em ratos diabéticos

Abstract

The present study evaluate the bone mechanical properties and structural characteristics in femur of diabetic rats submitted to hyperbaric oxygen therapy (HBO). Twenty-four rats were divided into groups, as follows: Control (CG); Control + HBO (CH); Diabetes (DG) and Diabetes + HBO (DH). The HBO was performed each 48h and started 30 days after streptozotocin diabetic induction. All animals were euthanized 60 days after diabetic induction. The mechanical properties, crosslink ratio (AI), crystallinity index (CI) and two mineral:matrix ratio (M:MI and M:MIII) were quantified in the femurs. ANOVA TWO-WAY and Tukey test were applied, statistical differences were considered when α < 0,05. In mechanical analysis, DG and DH showed lower values of strength, stiffness and energy than healthy animals CG and CH (P<0.007). However, there were increase strength and stiffness in HBO groups (CH and DH) compared with CG and DG (P<0.042). Fourier Transform Infrared Spectroscopy analyses showed that in DG there was decrease of mature crosslinks compared another groups (CG, CH and DH) (P=0.003). The CI values was reduced in DG and DH, compared with CG and CH (P=0.034). Mineral:matrix ratio the M:MI showed no statistical difference between CG, CH, DG and DH (P>0.278). In M:MIII there was increase of matrix mineral ratio in DH compared to CG and DG (P=0.035). The results suggest that the diabetic change the architecture of hydroxyapatite and collagen, characterized by reduction in the capacity to absorb energy, strength, stiffness and increase risk of fracture. However, HBO showed that important treatment to improved bone properties in diabetic rats.