Abstract
Aim: To evaluate the combined effects of streptozotocin-induced diabetes (Di) and ovariectomy in the articular cartilage of rats.
Methods: Forty adult female Wistar rats were ovariectomized (OVX) or sham-operated. After recovery from surgery, the animals were assigned randomly into four groups: OVX control (OVX-C); OVX treated with 10 µg/kg/day of 17β-estradiol (OVX-E); sham-operated subjected to Di (Sham-Di); and OVX subjected to Di (OVX-Di). After 60 days of treatment, the animals were euthanized and the distal femurs with articular cartilage were processed for paraffin-embedding. Sections were stained with hematoxylin and eosin for histomorphometry, Picro-Sirius Red for collagen, or Alcian Blue for glycosaminoglycan (GAG) content. To detect apoptosis, sections were stained with an antibody to cleaved caspase-3 (casp-3).
Results: Articular cartilage thickness and GAG content were significantly lower (p < 0.05) in the OVX-Di group, which also showed a higher number of casp-3-positive chondrocytes than the other groups. Interestingly, the higher percentage (p < 0.05) of mature collagen fibers was seen in the OVX-Di group, may be as a result of a reduced extracellular matrix remodeling of the articular cartilage.
Conclusion: Our results indicate that the combination of ovariectomy and streptozotocin-induced diabetes produces more deleterious effects in articular cartilage of rats than either condition alone.
Acknowledgements
The authors thank Mr Paulo Celso Franco for technical assistances and Mrs Cristiane de Paula Teixeira for estradiol assay support.
Conflict of interest
All authors declare no conflict of interest. The authors alone are responsible for the content and writing of this paper.