X-ray micro-analysis of cultured respiratory epithelial cells from patients with cystic fibrosis.
X-ray micro-analysis was carried out on cultured respiratory cells from polyps removed from individuals with and without cystic fibrosis (CF). In a first set of experiments, proper experimental conditions were established. Washing the cells with 300 mmol l-1 mannitol in distilled water was found to give the best removal of the culture medium. The elemental concentrations stabilized in about 10 min after the start of the preincubation. Intracellular [Na] and [Cl] increased slightly with increasing passage number, whereas intracellular [K] decreased. Under resting conditions there were no significant differences in elemental content between CF and control cells, and there were no indications for abnormally high total [Ca] in CF cells. In normal cells, stimulation with a cAMP-analogue resulted in a decrease of cellular [Cl], whereas in CF cells an increase was measured. Exposure of both normal and CF cells to ouabain resulted in decreased [K] and increased [Na] and [Cl] level. The calcium ionophore A23187 had a similar effect on normal cells but did not affect CF cells markedly. Application of amiloride to the apical side of the cells resulted in a decrease of cellular [Na] in CF cells, whereas [Na] in control cells was not affected. The results correspond with what is known about the defective cAMP-regulated transepithelial Cl-transport in CF cells. The effect of the calcium ionophore on cellular electrolyte content is more complicated and may be the result of two separate effects: efflux of Cl- via a Ca(2+)-dependent mechanism and inhibition of the Na(+)-K(+)-ATPase by intracellular Ca2+ ions causing an influx of Na+ and Cl- ions.
Sagström
S
S
Department of Human Anatomy, University of Uppsala, Sweden.
Roomans
G M
GM
Wroblewski
R
R
Keulemans
J L
JL
Hoogeveen
A T
AT
Bijman
J
J
D015124:8-Bromo Cyclic Adenosine Monophosphate / Q000494:pharmacology; D000584:Amiloride / Q000494:pharmacology; D000001:Calcimycin / Q000494:pharmacology; D002478:Cells, Cultured; D002712:Chlorides / Q000378:metabolism; D000242:Cyclic AMP / Q000096:biosynthesis; D003550:Cystic Fibrosis / Q000378:metabolism / Q000473:pathology*; D004577:Electron Probe Microanalysis; D004848:Epithelium / Q000378:metabolism; D006801:Humans; D010042:Ouabain / Q000494:pharmacology; D011188:Potassium / Q000378:metabolism; D012137:Respiratory System / Q000378:metabolism / Q000473:pathology*; D012964:Sodium / Q000378:metabolism
D002712:Chlorides; D015124:8-Bromo Cyclic Adenosine Monophosphate; D000001:Calcimycin; D010042:Ouabain; D000584:Amiloride; D012964:Sodium; D000242:Cyclic AMP; D011188:Potassium