사람 중이점막 상피세포에서 Uridine-5’ Triphosphate에 의한칼슘 이동과 점액분비에 미치는 카페인의 효과

Abstract

Background and Objectives：Puringeric receptors and their agonists like uridine-5-triphosphate (UTP) and adenosine triphosphate (ATP), regulate mucin secretion in middle ear epithelial cells. In the present study, we examined the effects of purinergic agonists on Ca2+ influx ([Ca2+]i) in normal human middle ear epithelial (NHMEE) cells. We also examined the effect of caffeine, an inositol 1, 4, 5-triphosphate (IP3) inhibitor, on UTP induced [Ca2+]i and mucin secretion in NHMEE cells.

Materials and Method：NHMEE cells were stimulated with various purinergic agonists, such as UTP, and [Ca2+]i was measured using a miniature double perfusion chamber. UTP-induced mucin secretion was quantitated by immunoblotting assay.

Results：The determined order of purinergic agonist potency with respect to [Ca2+]i was ATP=UTP>2-MeSATP>ADP>> adenosine. UTP-induced mucin secretion was inhibited when the intracellular Ca2+ was removed with 2-bis (2-aminophenoxy) ethane-N, N, N', N'-tetraacetic acid-acetoxymethyl ester. Caffeine suppressed UTP-induced [Ca2+]i, and but inhibited UTP-induced and constitutional mucin secretion.

Conclusion：Our results suggest that caffeine may have a therapeutic effect in mucoid otitis media by suppressing mucin secretion.