Korean J Otolaryngol-Head Neck Surg.  2006 Mar;49(3):263-268.

Effect of Caffeine on UTP-induced Ca2+ Mobilization and Mucin Secretion in Human Middle Ear Epithelial Cells

• Choi JY
• Kim SH
• Jung SH
• Son EJ
• Park HY
• Shin JW
• Yoon JH

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 UTPinduced and constitutional mucin secretion.
CONCLUSION
Our results suggest that caffeine may have a therapeutic effect in mucoid otitis media by suppressing mucin secretion.

Keyword

Mucin; Caffeine; Calcium

MeSH Terms

Adenosine
Adenosine Triphosphate
Caffeine*
Calcium
Ear, Middle*
Epithelial Cells*
Humans*
Immunoblotting
Inositol
Mucins*
Otitis Media
Perfusion
Purinergic Agonists
Uridine Triphosphate
Adenosine
Adenosine Triphosphate
Caffeine
Calcium
Inositol
Mucins
Purinergic Agonists
Uridine Triphosphate