Korean J Aerosp Environ Med.  1999 Mar;9(1):77-82.

Cause of Intracellular ATP dependency on Zn2++ Blockade of KATP Channels in Pancreatic Beta Cells

• Ahn YH
• Song DK

Abstract

In order to clarify the cause of intracellular ATP dependency on Zn2+ blockade of KATP channels in pancreatic beta cells, we investigated the KATP channel activity during external Zn2+ application using voltage clamp technique. Cultured beta cells were used for patch-clamp experiment. When 3 mM glucose was applied in bath, KATP channel activity was increased transiently by externally applied Zn2+ in the cell-attached mode and was recoverable. The KATP channel activity was, however, consistently increased by Zn2+ application during the 0 mM glucose in bath. Inside-out mode, internally applied Zn2+ elicited no response on the KATP channels. Another divalent cation, Mn2+, didn't have any effect on the KATP channels. Therefore, This effect, so-called external glucose-dependency on Zn2+ blockade of the KATP channels, might be due to intracellular Zn2+ metabolism which induces ATP consumption. This appears to be a mechanism that the Zn2+ blockade of the KATP channels in the pancreatic beta cells depends on the intracellular ATP concentration.

Keyword

KATP channel; Pancreatic beta cell; Zinc blockade; Intracellular ATP

MeSH Terms

Adenosine Triphosphate*
Baths
Glucose
Insulin-Secreting Cells*
KATP Channels*
Metabolism
Adenosine Triphosphate
Glucose
KATP Channels