Leukotriene c4 inhibits ciliary activity in the presence of gamma -glutamyl transpeptidase. Ganbo, Tetsuya, Ken-Ichi Hisamatsu, Hajime Inoue. Division of Otopathology, The Eye & Ear Institute, University of Pittsburgh, Pittsburgh, Department of Otolaryngology, Yamanashi Medical University, Yamanashi, Japan, Department of Plastic&Reconstructive Surgery, St. Marianna University School of Medicine, Kawasaki, Japan
APStracts 3:0058L, 1996.
We incubated human paranasal sinus mucosa in tissue culture with each of leukotrienes C4, D4 and E4 (LTC4, LTD4 and LTE4). Ciliary beat frequency (CBF) was measured photoelectrically, and the concentrations ofleukotrienes in the incubation medium were determined over time. LTC4 significantly decreased CBF within 2hr-, 4hr- and 8hr-exposures to 10-6M, 10-8M and 10-10M, respectively. Moreover, LTC4 dose-dependently reduced CBF to 81.4% of the initial value after 6hr-exposure to 10-6M, to 82.5% after 8hr-exposure to 10 -8M and to 89.7% after 12 hr-exposure to 10-10M. LTD4 also exhibited progressive ciliary inhibition while LTE4 had a minimal effect on CBF. In the medium, LTC4 was changed to LTD4 and further to LTE4. Gamma-glutamyl transpeptidase ([gamma]-GTP), an enzyme which converts LTC4 to LTD4, was detected in the mucosa. Serine-borate complex (SBC), an inhibitor of [gamma]-GTP, blocked the inhibitory effect of LTC4 on CBF. These findings suggest that LTC4 may induce ciliary inhibition indirectly by conversion to LTD4.

Received 10 August 1995; accepted in final form 1 April 1996.
APS Manuscript Number L251-5.
Article publication pending Am. J. Physiol. (Lung Cell. Mol.
Physiology).
ISSN 1080-4757 Copyright 1996 The American Physiological Society.
Published in APStracts on 1 May 96