HISTOCHEMISTRY AND IMMUNOHISTOCHEMISTRY OF EXTRACELLULAR-MATRIX OF RAT FETAL DUCTUS-ARTERIOSUS DURING THE INDOMETHACIN-INDUCED CONSTRICTION

Administration of anti-inflammatory non-steroidal drugs to pregnant an imals causes constriction of the fetal ductus arteriosus (DA). To clar ify the mechanism of the indomethacin-induced constriction of the rat fetal DA, extracellular matrix (ECM) components were observed by immun ohistochemical techniques with antibodies 2B1, 6B6, 3B3, 9A2 and other s to various kinds of proteoglycans (PGs). In the 10mg/kg group, the l arge PG revealed with antibody 2B1 was increased in the inner and oute r media at constriction, and chondroitin 6-sulfate PG was strongly imm unostained with antibody 3B3 as granular substances in the outer media , although no difference in stainability of chondroitin 4-sulfate PG r evealed with the antibody 9A2 was observed between experimental and co ntrol groups. This suggests that the cells composing the fetal DA show ed a tendency of proliferation and resultant production and aggregatio n of large PG with chondroitin 6-sulfate chains during constriction in duced by indomethacin-treatment.