Pathological studies on the impact of diabetes on periarthritis of shoulder formation

Abstract

Objective To explore the pathological changes and its formation mechanism in the shoulder joint of diabetic rats.Methods The 45 SPF male SD rats that weighing between 240 and 260 gram were randomly divided into two groups namely the control group (20) and the model group (25).The control group maintained by general diet.The model group fed with high sugar and high fat diet for 1 month,after that streptozocin (STZ) 30 mg/kg were injected into rats aiming to induce the model of type 2 diabetes (T2DM).After the success of modeling,take specimens from each rat group with bilateral shoulder cartilage,synovial membrane,surrounding muscles (including tendons),and other soft tissues,observe morphologic-al changes of specimens under light microscopy after HE staining.Enzyme-linked immunosorbent assay was used to detect the prostaglandin E-2 (PGE-2) of plasma and muscle,and also transforming growth factor-beta 1 (TGF-β1) levels; sample based hydrolysis to detect tendon hydroxyproline (HYP) content; the expression of the above indicators relative mRNA were detected by reverse transcriptase-polymerase chain reaction (RT-PCR).Results The shoulder pathological changes of model group and control group were 76.19％ and 10.00％ respectively,the difference was statistically significant (P ＜ 0.05).The pathological changes of articular cartilage,synovial membrane and tendons observed under microscope are similar,the main features are articular cartilage surface roughness,partly visible shallow crack of the extracellular matrix,velvet-like appearance of cartilage ; Synovial hypertrophy and fibrosis,synovial cell hypertrophy and the structure of tendon collagen fiber is loose,disorder and partial rupture.The PGE-2 content of plasma and muscle in model group were (39.13 ± 7.72),(42.18 ± 12.73) ng/L respectively,compared with the control group (18.86 ±6.35),(21.39 ±7.18) ng/L respectively,were increased (P ＜0.05).The TGF-β1 level of plasma and muscle in model group were (23.44 ± 7.28),(29.14 ± 7.33) μg/L respectively,compared with the control group (10.58 ± 3.52),(12.43 ± 4.56) μg/L respectively,were elevated (P ＜0.05).The HYP content of model group and control group were (119.42 ± 27.18),(64.19 ± 10.45) μg/g respectively,the difference was statistically significant (P ＜ 0.05).TGF-β1,PGE-2 and HYP mRNA expression of soft tissue in model group were 5.78 ± 0.90,8.29 ± 1.76,13.89 ±3.18 respectively,significantly higher than the control group (1.89 ±0.27,3.06 ± 0.60,7.22 ± 2.05),the difference was statistically significant (P ＜ 0.05).Conclusion Type 2 diabetes can result in inflammatory changes and fibrosis of rat shoulder cartilage,synovial membrane,surrounding muscles and other soft tissues.The above pathological features are consistent with the natural degeneration of shoulder soft tissue and periarthritis.Therefore,type 2 diabetes can be considered as one of the causes of periarthritis. Key words: Shoulder; Periarthritis ; Diabetes ; Etiology ; Degeneration