Cyclic AMP-stimulated fluid transport in the thyroid: influence of thyroid stimulators, amiloride and acetazolamide on the dynamics of domes in monolayer cultures of porcine thyroid cells.
Confluent monolayer cultures of porcine thyroid cells form dome-shaped elevations by local separation from the plastic culture dish. Formation of domes by epithelial cells in culture is generally considered to be evidence of fluid transport. A computer-controlled data acquisition system was developed to quantitate fluid transport in thyroid cultures by serial measurements of dome elevation. Thyrotrophin (10 mU/ml), prostaglandin E2 (PGE2; 0.01-1 mumol/l), forskolin (1 mumol/l), 8-(4-chlorophenylthio)adenosine 3':5'-cyclic monophosphate (0.5 mmol/l) and 3-isobutyl-1-methyl-xanthine (0.5 mmol/l) promoted increases in dome height over 5-120 min. Dome growth in the presence of PGE2 (1 mumol/l) was inhibited by amiloride (0.1-100 mumol/l), ouabain (200 mumol/l), or by removal of bicarbonate and glucose from the medium. In media of reduced bicarbonate concentration (1 mmol/l compared with the control concentration of 10 mmol/l), dome growth was inhibited by acetazolamide (0.01-1 mmol/l). These data are consistent with cyclic AMP-stimulated transport of fluid from apical to basal pole of the cells, dependent on sodium entry through the apical pole by an Na+/H+ exchanger.
Bourke
J R
JR
Department of Physiology and Pharmacology, University of Queensland, St Lucia, Australia.
Matainaho
T
T
Huxham
G J
GJ
Manley
S W
SW
D000086:Acetazolamide / Q000494:pharmacology*; D000584:Amiloride / Q000494:pharmacology*; D000818:Animals; D001692:Biological Transport; D002478:Cells, Cultured; D003470:Culture Media; D000242:Cyclic AMP / Q000502:physiology*; D015232:Dinoprostone; D005110:Extracellular Space / Q000378:metabolism*; D011458:Prostaglandins E / Q000494:pharmacology*; D013552:Swine; D013961:Thyroid Gland / Q000166:cytology / Q000187:drug effects* / Q000378:metabolism
D003470:Culture Media; D011458:Prostaglandins E; D000584:Amiloride; D000242:Cyclic AMP; D015232:Dinoprostone; D000086:Acetazolamide