Koivisto, Ari and Klinge, Andreas and Nedergaard, Jan and Siemen, Detlef (1998) Regulation of the activity of 27 pS nonselective cation channels in excised membrane patches from rat brown-fat cells. CELLULAR PHYSIOLOGY AND BIOCHEMISTRY, 8 (5). pp. 231-245. ISSN 1015-8987, 1421-9778
Full text not available from this repository. (Request a copy)Abstract
The regulation of the activity of the approximate to 30 pS nonselective cation channel (NSC channel) was studied by the patch-clamp technique in inside-out patches obtained from rat brown-fat cells. NSC channel activity was induced by excision; reduced redox state induced by dithiothreitol accelerated the kinetics in the excised state. The NSC channels were inhibited by the fenamates flufenamic acid and mefenamic acid but not by NS-1619 or SKF-96365, The channels were inhibited by purine nucleotides but not by polyamines, No evidence for protein kinase C, CaM kinase or protein kinase A activation of the NSC channel was obtained. NSC-channel activity was stimulated in a concentration-dependent manner by Ca(2+) but the EC(50) was very high (0.81 mM), in comparison to expected cytosolic Ca(2+) levels, In the presence of ATP, even higher Ca(2+) levels were necessary for comparable NSC-channel activation. The increase in P(o) was not associated with an increase in open-time constants, We conclude that although high Ca(2+) levels can experimentally activate the NSC channel, a further mediatory step must probably be postulated in order to link alpha(1)-adrenergic stimulation to NSC-channel activation.
| Item Type: | Article |
|---|---|
| Uncontrolled Keywords: | ADIPOSE-TISSUE; CALCIUM; ACTIVATION; MODULATION; ADIPOCYTES; CA-2+; LINE; K+; EXOCYTOSIS; POLYAMINES; cation channel; calcium sensitivity; brown-fat cells |
| Subjects: | 500 Science > 590 Zoological sciences |
| Divisions: | Biology, Preclinical Medicine > Institut für Zoologie |
| Depositing User: | Dr. Gernot Deinzer |
| Date Deposited: | 28 Mar 2023 04:57 |
| Last Modified: | 28 Mar 2023 04:57 |
| URI: | https://pred.uni-regensburg.de/id/eprint/50177 |
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