ISSN:
1420-9071
Keywords:
Bladder
;
cell membrane permeability
;
Na−K ATPase
;
digitalis
;
natriuretic factor
;
ouabain
;
ammonium chloride
Source:
Springer Online Journal Archives 1860-2000
Topics:
Biology
,
Medicine
Notes:
Summary Electrical changes and direct effects on Na−K ATPase activity induced by an endogenous digitalis-like natriuretic factor (NF), NH4Cl and ouabain were studied in toad bladders. NF inhibited the SCC and the Na−K ATPase activity in a similar manner to ouabain, but induced a greater increase in calculated direct current resistance (R) (p〈0.05). NH4Cl was a weak inhibitor of Na−K ATPase activity, although it produced steeper SCC inhibition slopes than those observed with ouabain or NF (p〈0.01). The data suggested the same mechanism of action of NF and ouabain on the sodium pump, with an additional effect of the former on apical sodium permeability of the cells and/or closure of paracellular routes leading to an increased tissue resistance. In contrast, the effects of NH4Cl were mostly compatible with intracellular inhibition of apical sodium entry into the cell.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF01946401
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