The Change Regularity Of Protein Kinase B In The Articular Cartilage Of Osteoarthritis And Osteoarthritis-ovariectomy Rat Models

Objective To research regularity for change of protein Kinase B in the articular cartilage of osteoarthritis(OA) process in OA and OA-ovariectomy rat models.Methods 72 female Sprague-Dawley rats were used in this study. 16 rats were the control group, 56 rats were performed operation at both knees to induce OA by anterior cruciate ligament transection (ACLT) in combination with resection of part medial menisci (part-MMx). At 6 weeks, we detected the OA model by killing 8 rats(ACLT+ part-MMx), compared with 4 control rats. The other 48 rats were divided into two group: OA group(24 rats) and OVX + OA group(24rats). The OVX + OA group was performed by both side ovariectomy. The articular cartilage in medial femoral condyle and femoral trochlea of control rats(4 ), OA rats(8 ) and OVX + OA rats (8) were acquired at 9, 12, and 16 weeks postoperation, respectively. We observed the morphological change of the articular cartilage in OA rat model by histological technique, including haemotoxylin(H.E.) and safranin O, and detected the expression of Akt and P-Akt by immunohistochemical technique and Western-Blotting from 6 to 16-week post-operation. All data were analyzed in SPSS statistical program.Results We established the OA and OA-OVX rat model, in which the morphological change of articular cartilage is accordance with the histopathological structure of OA. However, it is no significant morphological change in the articular cartilage following the decrease of estrogen by OVX in OA rat model (P>0.05). Furthermore, we observed that the expression of Akt and P-Akt in articular cartilage in OA-OVX model is significantly lower than that in OA model (P<0.05).But the expression of Akt and P-Akt in articular cartilage gradually increased in a time-dependent manner from 6 to 12-week post-operation (P<0.01), and then the expression of Akt and P-Akt decreased rapidly in 16-week post-operation (P<0.05),whether in OA or in OA-OVX rat model.Conclusion It is adoptable to establish the OA rat model by ACLT and part-MMX. And it is no more significant effect on the morphological structure of articular cartilage after OVX in OA rat model. It is suggested that the decrease of estrogen by OVX may be associated with the decrease of the expression of Akt and P-Akt.