ATP-sensitive K+ transport in adrenal chromaffin granules

• Authors: A. Szewczyk , N.A. Lobanov , A. Kicinska , G. Wojcik , M.J. Nalecz
• Languages of publication: EN

Abstracts

EN

In the present study the influx of 86Rb+, a K+ analogue, was studied in mitochondria, microsomes and chromaffin granules prepared from adrenal gland medulla. The most active electrogenic 86Rb+ transport was found in the membrane fraction identified as chromaffin granules by marker enzyme estimation. The transport was found to be sensitive to ATP, ATPS, ADP and to the triazine dyes, but not to AMP and cAMP. The inhibition induced by ATP was observed in the absence of externally added Mg2+, suggesting that a free nucleotide, rather than the ATP-Mg complex, was required for inhibition. Furthermore, the 86Rb+ influx was found to be inhibited by Mg2+ alone, but not by Ca2+ and antidiabetic sulfonylureas. The 86Rb+ influx was not stimulated by potassium channel openers. In conclusion, our results indicate that an electrogenic, ATP-sensitive potassium transport system operates in the chromaffin granule membrane.

Keywords

EN

ADRENAL CHROMAFFIN GRANULE; ATP; POTASSIUM; POTASSIUM CHANNEL; POTASSIUM CHANNEL OPENER; POTASSIUM TRANSPORT

Discipline

• EXPERIMENTAL_BIOLOGY_&_MEDICINE: EXPERIMENTAL BIOLOGY & MEDICINE

• Publisher: Marceli Nencki Institute of Experimental Biology, Polish Academy of Sciences
• Journal: Acta Neurobiologiae Experimentalis
• Year: 2001
• Volume: 61
• Issue: 1
• Pages: 1-12

Contributors

author

A. Szewczyk

author

N.A. Lobanov

author

A. Kicinska

author

G. Wojcik

author

M.J. Nalecz

• Document Type: ARTICLE
• Publication order reference: A. Szewczyk, Laboratory of Intracellular Ion Channels, Nencki Institute of Experimental Biology, Polish Academy of Sciences, 3 Pasteur St., 02-093 Warsaw, Poland