Characterization of an ATP-modulated large conductance Ca2+-activated K+ channel present in rat cortical neurones

Lee, K., Rowe, I.C.M. and Ashford, M.L.J. (1995) Characterization of an ATP-modulated large conductance Ca2+-activated K+ channel present in rat cortical neurones. Journal of Physiology, 488(2), pp. 319-337. (doi: 10.1113/jphysiol.1995.sp020969) (PMID:8568673)

Full text not currently available from Enlighten.

Abstract

1. Single channel current recordings were used to study the characteristics of a large conductance Ca(2+)-activated K+ (BKCa) channel present in neurones acutely dissociated from the rat motor cortex. Application of ATP to the intracellular surface of excised inside-out patches produced a large, concentration-dependent increase in BKCa channel activity. 2. This ATP-mediated activation was dependent upon the presence of Mg2+ in the intracellular bathing solution and was diminished by the phosphatases 2,3-butanedione monoxime (BDM) or alkaline phosphatase and by the protein kinase inhibitors staurosporine, H-7 and PKI. 3. ADP stimulated BKCa channel activity in a Mg(2+)-dependent manner, an action also inhibited by the concomitant application of PKI or BDM. The effect of ADP was reduced by application of hexokinase and glucose or by application of the adenylate kinase inhibitor Ap5A. 4. Of other nucleotides tested, only CTP consistently activated BKCa channel activity. 5. Using the cell-attached configuration, bath application of forskolin or dibutyryl cAMP stimulated BKCa channel activity. 6. It is concluded that BKCa channel activity in the rat motor cortex is subject to modulation by the activity of a closely associated kinase. The ability of cAMP activators to stimulate BKCa channel activity in the intact cell suggests that this system may be of physiological importance.

Item Type:Articles
Status:Published
Refereed:Yes
Glasgow Author(s) Enlighten ID:Rowe, Dr Iain
Authors: Lee, K., Rowe, I.C.M., and Ashford, M.L.J.
College/School:College of Medical Veterinary and Life Sciences > School of Life Sciences
Journal Name:Journal of Physiology
Publisher:Physiological Society
ISSN:0022-3751
ISSN (Online):1469-7793

University Staff: Request a correction | Enlighten Editors: Update this record