[Effect of ionising irradiation on outward potassium current in the aorta smooth muscle cells in rats: the role of protein kinase C].
It is known that gamma-irradiation leads to vascular hyperfunction and hypertension development. In this study we tested the hypothesis 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 Ca(2+) 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 technique. It has been shown that the basic component of outward K+ current in rat aortic smooth muscle cells is a large conductance Ca(2+)-activated K+ current (BK(Ca)). BK(Ca) currents in smooth muscle cells obtained from irradiated animals on the 9th and 30th days post-irradiation demonstrated a significant decrease of K(+)-current density amplitudes. Protein kinase C inhibitor, chelerythrine, effectively restored BK(Ca) current reduced by ionizing irradiation. In conclusion, the results suggest that gamma-irradiation suppressed BK(Ca) current in vascular smooth muscle cells, and this effect is mainly due to activation of protein kinase C.
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Ivanova
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Solovĭov
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D000818:Animals; D001013:Aorta, Thoracic / Q000166:cytology / Q000201:enzymology / Q000378:metabolism / Q000528:radiation effects*; D053119:Benzophenanthridines / Q000494:pharmacology; D001794:Blood Pressure / Q000528:radiation effects; D018929:Cell Culture Techniques; D002478:Cells, Cultured; D008297:Male; D008564:Membrane Potentials / Q000528:radiation effects; D009131:Muscle, Smooth, Vascular / Q000166:cytology / Q000201:enzymology / Q000378:metabolism / Q000528:radiation effects*; D018408:Patch-Clamp Techniques; D015221:Potassium Channels / Q000378:metabolism*; D024681:Potassium Channels, Calcium-Activated / Q000378:metabolism; D011493:Protein Kinase C / Q000037:antagonists & inhibitors / Q000502:physiology*; D011839:Radiation, Ionizing; D051381:Rats; D017208:Rats, Wistar; D014916:Whole-Body Irradiation
D053119:Benzophenanthridines; D015221:Potassium Channels; D024681:Potassium Channels, Calcium-Activated; C016299:chelerythrine; D011493:Protein Kinase C