Measurement of Na-K pump current in acinar cells of rat lacrimal glands.
Biophys J
; 55(3): 571-4, 1989 Mar.
Article
em En
| MEDLINE
| ID: mdl-2539211
Isolated cells from rat lacrimal glands were voltage clamped using the tight-seal whole-cell recording technique. The intracellular solution contained ATP and an elevated Na concentration (70 mM). Removing external K ions elicited an inward current shift. Ouabain (0.5 mM) induced an inward current shift of identical amplitude, but with slower kinetics. In the presence of ouabain, removal of K ions did not alter the cell current. The potassium- and ouabain-sensitive current was outward between -120 and +20 mV, and its amplitude decreased below -60 mV. This current was highly sensitive to temperature, and was not affected by blockers of the K channels which are present in these cells. It was attributed to an inhibition of the Na-K pump. The Na-K pump current was estimated to be 15 pA for an average acinar cell at physiological temperature, with 70 mM internal Na ions and 20 mM external K ions. Implications of this value in terms of electrolyte secretion are discussed.
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
ATPase Trocadora de Sódio-Potássio
/
Aparelho Lacrimal
Limite:
Animals
Idioma:
En
Revista:
Biophys J
Ano de publicação:
1989
Tipo de documento:
Article
País de afiliação:
Venezuela
País de publicação:
Estados Unidos