Cp. Kahler et Wj. Duplooy, EFFECTS OF FUROSEMIDE AND SALBUTAMOL ON HISTAMINE-INDUCED AND METHACHOLINE-INDUCED CONTRACTION OF THE ISOLATED GUINEA-PIG TRACHEAL CHAIN, Medical science research, 24(7), 1996, pp. 451-453
The relaxant effect of furosemide on histamine- and methacholine-induc
ed contraction was investigated in guinea-pig trachea in vitro with an
d without epithelial cells. The isolated tracheas of four to six guine
a-pigs were used in each experiment and suspended in organ baths, fill
ed with Krebs-Henseleit solution and aerated with 95% O-2 and 5% CO2.
Furosemide (3 x 10(-5) M) produced a relaxation of 65.3 +/- 9.0% after
histamine-induced contraction and 101.2 +/- 3.9% (3 x 10(-4) M) after
methacholine-induced contraction compared to salbutamol (100%). At hi
gher concentrations furosemide produced a relaxation of 74.8 x 2.5% af
ter 10(-4) M furosemide for histamine-induced contraction and 110.4 +/
- 5.3% (10(-3) M furosemide) for methacholine-induced contraction. Epi
thelial cell removal had no effect on the relaxant effect of furosemid
e for either agonist. Indomethacin pre-incubation (10(-6) M) also had
no effect on the relaxant effect of furosemide for either agonist. The
se findings suggest that epithelial cells and their mediators are not
involved in the relaxant effect of furosemide, and that the products o
f the cyclooxygenase pathway do not affect the smooth muscle relaxatio
n caused by furosemide.