AJP - Gastrointestinal and Liver Physiology, Vol 265, Issue 6 1021-G1028, Copyright © 1993 by American Physiological Society
Leukotriene B4 and C4 production in isolated rat gastric mucosal cells
W. Huber, M. Trautmann, I. Becker, U. Schenck, B. M. Peskar and W. Schepp
Department of Internal Medicine II, Technical University of Munich, Germany.
Dispersed rat gastric mucosal cells (F0) were separated into five fractions
(F1-F5) by counterflow elutriation, with F1 representing the smallest and
F5 the largest cell diameters. In F0-F5, leukotriene B4 (LTB4) release in
response to 10(-5) M calcium ionophore A-23187 was 7.68 +/- 1.26, 51.6 +/-
10.8, 72.4 +/- 10.4, 7.1 +/- 0.7, 5.7 +/- 0.6, and 11.6 +/- 3.4 pg.10(6)
cells-1 x 30 min-1. In the identical fractions, sulfidopeptide release in
response to A-23187 was 200.6 +/- 20.5, 1,116.0 +/- 166.6, 1,309.4 +/-
163.2, 189.8 +/- 25.8, 108.0 +/- 18.0, and 158.4 +/- 54.0 pg.10(6) cells-1
x 30 min-1. High-pressure liquid chromatography verified the
radioimmunologically determined LTB4 and identified LTC4 as the only
sulfidopeptide LT released. LT release from F2 cells in response to A-23187
was time and dose dependent, reaching maximal stimulation at 10(-5) M
A-23187. This response was blocked by the dual inhibitor of cyclooxygenase
and lipoxygenases, BW755C (2 x 10(-5)-2 x 10(-4) M), by the selective
5-lipoxygenase inhibitor L-651,392 (10(-7)-10(-5) M), and by MK-886
(10(-9)-10(-7) M), which blocks translocation of 5-lipoxygenase. The
postreceptor stimuli dibutyryl adenosine 3',5'-cyclic monophosphate,
forskolin, 12-O-tetradecanoyl-phorbol-13-acetate, and oleyl-acetyl-glycerol
failed to induce LT release. However, 10(-4) M arachidonic acid increased
basal LT release up to eightfold and increased A-23187-stimulated LT
release by an additional 30%.(ABSTRACT TRUNCATED AT 250 WORDS)
