Leptin activates ATP-sensitive potassium channels in the rat insulin-secreting cell line, CRI-G1.
J Physiol
; 504 ( Pt 3): 527-35, 1997 Nov 01.
Article
em En
| MEDLINE
| ID: mdl-9401961
1. Whole-cell current-clamp recordings demonstrate that leptin (0.3-10 nm) hyperpolarizes CRI-G1 insulin-secreting cells. This effect is slow on onset and is not reversed on washout of the leptin. 2. Voltage-clamp recordings indicate that leptin activates a potassium conductance in the presence of intracellular ATP (5 mm), but has not effect in its absence. Following activation of ATP-sensitive K+ (KATP) current by diazoxide (0.2 mm), addition of leptin did not alter cell membrane potential or potassium current further. 3. The leptin-induced hyperpolarization and increased potassium conductance are completely inhibited by the application of the sulphonylureas tolbutamide (100 microM) and glibenclamide (0.5 microM). 4. Cell-attached and inside-out single-channel recordings indicate that leptin activates tolbutamide-sensitive KATP channels in CRI-G1 insulin-secreting cells.
Texto completo:
1
Base de dados:
MEDLINE
Assunto principal:
Canais de Potássio
/
Proteínas
/
Trifosfato de Adenosina
/
Insulina
Idioma:
En
Ano de publicação:
1997
Tipo de documento:
Article