OBJECTIVETo investigate the effect of sodium cromoglycate on experimental endometriosis in rats.

METHODSEndometriosis model was established in 36 unpregnant female SD rats by transplanting autologous fragments of endometrium to the inner surface of the abdominal wall. The endometriotic lesions were measured by a second laparotomy 2 weeks after surgery. Then the rats were randomly divided into four groups (n=8 in each group) to receive intraperitoneal injection of different doses of sodium cromoglycate for 2 weeks: high-dose group (20 mg·kg⁻¹·d⁻¹); low-dose group (10 mg·kg⁻¹·d⁻¹); the negative control group and the blank control group. The animals were sacrificed and the size of the lesions were measured. The endometriosis model of SD rats was identified by HE staining and immunohistochemical staining of keratin and vimentin. The total number of mast cells and their degranulation were measured by Toluidine blue staining; the concentrations of TNF-α in serum were measured by enzyme linked immunosorbent assay; the concentrations of estradiol in serum were measured by enzyme immunoassay; the expression of tryptase and nerve growth factor (NGF) were measured by immunohistochemical staining.

RESULTSThe number of activated mast cells (MC) by Toluidine blue staining in high-dose group was significantly lower than that in negative control group (P<0.05), and its ratio of degranulation/total number of MC was significantly lower than that in negative control group or blank control group (P<0.05). The serum TNF-α levels and tryptase expression in tissues in high-dose group were significantly lower than those in negative control group or blank control group (P<0.05). However, no significant difference in the size of endometriotic lesions and expression of NGF was found among groups (P>0.05).

CONCLUSIONSodium cromoglycate can stabilize mast cells from degranulation, which may relieve the clinical symptoms of endometriosis by reducing TNF-α and tryptase levels.