Effects of cardiogenic edema fluid on ion and fluid transport in the adult lung.
We have previously shown that cardiogenic pulmonary edema fluid (EF) increases Na(+) and fluid transport by fetal distal lung epithelia (FDLE) (Rafii B, Gillie DJ, Sulowski C, Hannam V, Cheung T, Otulakowski G, Barker PM and O'Brodovich H. J Physiol 544: 537-548, 2002). We now report the effect of EF on Na(+) and fluid transport by the adult lung. We first studied primary cultures of adult type II (ATII) epithelium and found that overnight exposure to EF increased Na(+) transport, and this effect was mainly due to factors other than catecholamines. Plasma did not stimulate Na(+) transport in ATII. Purification of EF demonstrated that at least some agent(s) responsible for the amiloride-insensitive component resided within the globulin fraction. ATII exposed to globulins demonstrated a conversion of amiloride-sensitive short-circuit current (I(sc)) to amiloride-insensitive I(sc) with no increase in total I(sc). Patch-clamp studies showed that ATII exposed to EF for 18 h had increased the number of highly selective Na(+) channels in their apical membrane. In situ acute exposure to EF increased the open probability of Na(+)-permeant ion channels in ATII within rat lung slices. EF did increase, by amiloride-sensitive pathways, the alveolar fluid clearance from the lungs of adult rats. We conclude that cardiogenic EF increases Na(+) transport by adult lung epithelia in primary cell culture, in situ and in vivo.
Gandhi
Shephali G
SG
Canadian Institutes of Health Research Group in Lung Development, University of Toronto, Toronto, Ontario, Canada.
Rafii
Bijan
B
Harris
Michael S
MS
Garces
Alexandra
A
Mahuran
Don
D
Chen
Xi-Juan
XJ
Bao
Hui-Fang
HF
Jain
Lucky
L
Eaton
Douglas C
DC
Otulakowski
Gail
G
O'Brodovich
Hugh
H
D000818:Animals; D001692:Biological Transport; D001798:Blood Proteins / Q000378:metabolism; D002395:Catecholamines / Q000378:metabolism; D002462:Cell Membrane / Q000378:metabolism; D016764:Cell Polarity; D002478:Cells, Cultured; D004847:Epithelial Cells / Q000166:cytology / Q000378:metabolism; D053503:Epithelial Sodium Channels / Q000378:metabolism; D015633:Extravascular Lung Water / Q000378:metabolism*; D015640:Ion Channel Gating; D007473:Ion Channels / Q000378:metabolism; D008168:Lung / Q000378:metabolism*; D008297:Male; D011650:Pulmonary Alveoli / Q000378:metabolism; D011654:Pulmonary Edema / Q000378:metabolism*; D051381:Rats; D017207:Rats, Sprague-Dawley; D012964:Sodium / Q000378:metabolism
D001798:Blood Proteins; D002395:Catecholamines; D053503:Epithelial Sodium Channels; D007473:Ion Channels; D012964:Sodium