Interventional effect of sodium hyaluronate on inducible nitric oxide synthase mRNA expression in cartilage of rabbits with traumatic osteoarthritis / 中国组织工程研究

ABSTRACT

BACKGROUND: Traumatic osteoarthritis (OA) resulted from the injury of joints and postoperation of joints is commonly observed. Intra-articular injection of sodium hyaluronate (Na-HA) has been considered as effective method for OA. OBJECTIVE: To observe the influence of intra-articular injection of NaHA on mRNA expression of inducible nitric oxide synthase (iNOS) in cartilage of traumatic OA induced by transection of anterior cruciate ligament. DESIGN: Randomized controlled animal experiment. SETTING: Department of Orthopaedics, Renmin Hospital, Wuhan Uni ersity. MATERIALS The experiment was performed in Laboratory of Depart ment of Orthopaedics, Renmin Hospital, Wuhan University from April to December 2003, in which, 16 clean healthy flat-eared white rabbits, aged 5-6 months were employed. The rabbits were randomly divided into Na- HA injection group and saline control group with 8 rabbits in each group. Na-HA (2000, No 366095) was provided by Shanghai Jiahua Fine Biologi- cal Products Co. METHODS: ①OA model was established in rabbits of the two groups. Each rabbit was anesthetized intravenously with 1.0 mg/kg ketamine hy- drochloride and underwent unilateral anterior cruciate ligament transection. ②5 weeks after transection, Na-HA injection group rabbits received 0.3 mL of intra-articular 10 g/L Na-HA injection, once a week for 5 weeks. Ani mals in saline controlled group were treated with saline of the same vol ume. ③The rabbits were killed at week 10 after operation, general morphology and histopathological changes of articular cartilage degeneration of medial femoral condyle were evaluated (0 points as smooth articular surface with normal color and luster; 1 point as minimal fibrillation or a slight crevice and dark grey color of the surface; 2 points as erosion extending into superficial or middle layers of cartilage; 3 points as ulceration and erosion extending into the deep layers, and 4 points as denudation of cartilage, erosion extending to the sub-chondral bone). The mRNA expression of iNOS in cartilages was examined with reverse transcription-polymerase chain reaction (RT-PCR). MAIN OUTCOME MEASURES: ①Observation of articular cartilage degeneration of medial femoral condyle, ②observation of articular cartilage degeneration of medial femoral condyle at light microscopic level, ③expression of iNOS in cartilages of each group. RESULTS: A total of 16 clean healthy rabbits entered the result analysis. ① Result of articular cartilage degeneration of medial femoral condyle Pathological change of articular surface of femoral condyle was observed under anatomic microscope. Cartilage degradation in experimental group was significantly less severe than that in saline control group. ②Histological changes of articular cartilage degeneration of medial femoral condyle at light microscopic level The Na-HA injection group showed cartilage changes Membrane of cartilage presented denaturalization and abscission. Chondrocytes of superficial zone presented denaturalization, necrosis, turbulence and erosion. Animals treated with saline showed denaturalization, necrosis and disorder of chondrocytes, ulceration penetrating into the middle or deep zone of the cartilage. New hyperplasia of capillary vessels and fibroblasts were more obvious. Proliferation of fibrous tissue appeared at the bottom of ulcer. ③Expression of iNOS in cartilages of two groupThe gene expression of iNOS in cartilage of Na-HA injection group was(1.09±0.18) and the expression of saline control group was (1.26±0.23). Nosignificant difference of iNOS expression was found between the two groups(P ＞ 0.05).CONCLUSION: Intra-articular injection of Na-HA has protective and repairing effect on cartilage with early OA and can significantly reduce the severity of cartilage degradation during early stage of traumatic OA. Intra-articular injection of Na-HA does not down-regulated iNOS expression in cartilage.