Effect of ionising irradiationon outward k+ current in rat aortasmooth muscle cells: the roleof protein kinase c
Kizub I.V., Ivanova I.V., Pavlova O.O., Soloviev A.I.
Institute of Pharmacology and Toxicology of Academy ofMedical Sciences of Ukraine, Kyiv, Ukraine
Abstract
It is known that ?-irradiation leads to vascular hyperfunction
and hypertension development. In this study we tested the hy-
pothesis that ionizing irradiation directly affects vascular smooth
muscle cells due to damage in outward K+ channel function.
The goal of this study was to evaluate the influence of whole-
body ionizing irradiation (6 Gy dose) on Ca2+- dependent K+
channels and to clarify a possible involvement of protein kinase
C in this process. Experiments were conducted on isolated rat
aorta smooth muscle cells using whole-cell patch clamp tech-
nique. It has been shown that the basic component of outward
K+ current in rat aortic smooth muscle cells is a large
conductance Ca2+-activated K+ current (BK Ca,). BKCa currents
in smooth muscle cells obtained from irradiated animals on the
9th and 30th days post-irradiation demonstrated a significant de-
crease of K+-current density amplitudes. Protein kinase C in-
hibitor, chelerythrine, effectively restored BKCa current reduced
by ionizing irradiation. In conclusion, the results suggest that
?-irradiation suppressed BKCa current in vascular smooth muscle
cells, and this effect is mainly due to activation of protein kinase C.
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