ABSTRACT
Objective Interleukin-21(IL-21) is likely to contribute to the development of liver fibrosis, but up to now, no study has been reported on the relationship between IL-21 and intrauterine adhesions ( IUA) .This study aimed to establish a rat model of IUA induced by mechanical injury and lipopolysaccharide (LPS) infection (dual injury), determine the expression level of serum IL-21, and confirm the association of serum IL-21 with the formation of IUA. Methods Forty healthy female SD rats were randomly divided into four groups of equal number,control, mechanical injury, LPSinfection, and dual injury.At 7 days after IUA modeling,uterine tissue-swere collected from all the animals for observation of the endometrial glands,detection of the degree of IUA by Masson staining, measure-ment of the serum IL-21 level by radioimmunoassay, and analysis of the correlation between the number of endometrial glands and the de-gree of fibrosis. Results The number of endometrial glandswas significantly smallerin the dual injury group (3.59±1.20) than in the mechanical injury (11.66±2.34) and LPSinfection group(11.59±1.47)(P<0.05), while the proportion of fibrosis area wassignificantly higher in the former group(0.65±0.03) than in the lattertwo(0.30±0.07 and 0.32±0.08)(P<0.05).The level of serum IL-21 was signifi-cantly increased in the dual injury group ([286.21±27.80]pg/mL) as compared with those in the control ( [ 118.65 ±22.55 ] pg/mL ) , mechanical injury([176.20±19.05]pg/mL), and LPS infection group ([187.98±16.51]pg/mL) (P<0.05), with a positive correlation be-tween the IL-21 level and theproportion of fibrosis area ( r=0.271, P<0.05) . Conclusion A rat model ofIUAwas successfully established by mechanical injury and lipopolysaccharide (LPS) infection.The evi-dent increase of serum IL-21 in the IUA model was positively correlated with the percentage of fibrosis area, suggesting that IL-21 may be involved indirectly in the formation of IUA.