Fatty acid modifies Ca 2+ -dependent potassium channel activity in smooth muscle cells from the human aorta

The Royal Society - Tập 237 Số 1288 - Trang 259-266 - 1989
Pìotr Bregestovski1, Victoria M. Bolotina, V. N. Serebryakov
1Institute of Experimental Cardiology, Academy of Medical Sciences, Moscow, U.S.S.R.

Tóm tắt

By using the patch–clamp technique the effect of 2-decenoic acid (DA) on Ca 2+ -activated potassium (K + ) channels in the membrane of smooth muscle cells from the human aorta was studied. In the presence of 0.5 μM Ca 2+ and 2 mM Mg 2+ on the cytoplasmic side of the membrane, a more than tenfold elevation in the probability of the channels being open ( p o ) was observed under the effect of DA. With divalent cation concentrations of less than 1 nM DA caused a more than twofold elevation in p o . In the DA-treated membranes Mg 2+ ions, which normally fail to activate the channels, brought about a nearly threefold increase in the channel activity when applied to the inner membrane surface. Channel sensitivity to the activating effect of cytoplasmic Ca 2+ ions did not increase with the application of DA. Single-channel conductance was unchanged by DA exposure. We suggest that DA alters the Ca 2+ -binding mechanism of the channel, increasing its sensitivity to Mg 2+ ions, presumably owing to membrane fluidization.

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Tài liệu tham khảo

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The Royal Society

Tập 237 Số 1288

259-266

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