Bumetanide and bicarbonate increase short-circuit current in fetal lung epithelium.
1. We studied the effects of bumetanide (a Na+/K+/2Cl- cotransport inhibitor) and HCO3(-) on beta-adrenergic-agonist-stimulated short-circuit current (beta-Isc) in rat fetal distal lung epithelium (FDLE). 2. Bumetanide significantly increased beta-Isc in the absence of amiloride but decreased it in its presence. The amiloride- and bumetanide-insensitive beta-Isc was diminished by a removal of HCO3(-) in the bathing solution. 3. Our results suggest that bumetanide stimulates the amiloride-sensitive beta-Isc in FDLE and that the amiloride-insensitive beta-Isc is composed of two different pathways: bumetanide-sensitive and HCO3(-)-dependent Cl- secretion in FDLE.
Marunaka
Y
Y
MRC Group in Lung Development and Division of Respiratory Research, University of Toronto Faculty of Medicine, Ontario.
Doi
Y
Y
Nakahari
T
T
D000318:Adrenergic beta-Agonists; D000584:Amiloride / Q000819:agonists; D000818:Animals; D002021:Buffers; D002034:Bumetanide / Q000494:pharmacology*; D004232:Diuretics / Q000819:agonists / Q000494:pharmacology*; D004847:Epithelial Cells; D005333:Fetus; D017136:Ion Transport; D008168:Lung / Q000187:drug effects*; D051381:Rats; D017208:Rats, Wistar; D017693:Sodium Bicarbonate / Q000494:pharmacology*; D013726:Terbutaline / Q000819:agonists
D000318:Adrenergic beta-Agonists; D002021:Buffers; D004232:Diuretics; D002034:Bumetanide; D000584:Amiloride; D017693:Sodium Bicarbonate; D013726:Terbutaline