Ionizing non-fatal whole-body irradiation inhibits Ca²⁺-dependent K⁺channels in endothelial cells of rat coronary artery: Possible contribution to depression of endothelium-dependent vascular relaxation

Abstract

The results suggest that non-fatal, whole-body gamma-irradiation suppresses large conductance, calcium-activated potassium channels, which control the driving force for Ca2+ entry and therefore Ca2+ dependent nitric oxide (NO) synthesis in endothelial cells. This may contribute, in part, to radiation-induced endothelium dysfunction and an increase in arterial blood pressure.

Electrophysiological and contractile evidence of the ability of human mesenchymal stromal cells to correct vascular malfunction in rats after ionizing irradiation

“…current carried through BK Ca channels, is the most vulnerable component of total outward current in SMC. Taking into account our previous experiments [2], in which we demonstrated radiation-induced BK Ca suppression in endothelial cells, it became obvious that both of the two main vasorelaxation forces in the vascular wall (endothelium-dependent relaxation and relaxation of SMC related to membrane hyperpolarization) will be defective following radiation treatment.…”

“…-activated K ? channel (BK Ca ) activity in endothelial cells [2]. Nevertheless, although endothelium is the most radiation-sensitive and vulnerable component of the vascular wall, the studies performed have shown that irradiation has the ability to enhance vascular contractility in an endothelium-independent manner [3,15].…”

“…-dependent potassium channels (BK Ca ) activity in endothelial cells seems to be one of the most vulnerable mechanisms of vasodilatation in vascular wall under irradiation [1,2]. It has recently been shown that both BK Ca channels function and expression in smooth muscle cells (SMC) are very sensitive to radiation, suggesting that the vasodilator potential of vascular smooth muscle had decreased following irradiation [3].…”

“…Restrictase EarI was employed in some cases for the verification of PCR products with a single restriction site (expected sizes of both fragments are indicated also). MSCs(1)(2)(3)(4)(5)(6)(7)(8)(9)(10)(11)(12)(13)(14)(15)(16), bone marrow progenitors(18)(19)(20): 1 CD45, 2 CD34, 3 CD14, 4 CD71, 5 CD29, 6 CD29/EarI, 7 CD44, 8 CD44/EarI, 9 CD105, 10 CD105/EarI, 11 CD73, 12 CD73/ EarI, 13 CD166, 14 CD166/EarI, 15 CD90, 16 CD90/EarI, 17 50 base-pair ladder, 18 CD45, 19 CD34, Endothelium-dependent acetylcholine-induced vascular responses in rat thoracic aorta rings obtained from healthy (open circles) and irradiated (open squares) rats and hMSC treated nonirradiated (closed circles) and post-irradiated (closed squares) animals. hMSC were administered intravenously on the 7th day after irradiation (6 Gy).…”

Possible Role of Garlic Oil and Parsley Extract in Ameliorating Radiation-Induced Bone Loss in Female Rats

“…Our results showed that exposure of rats to 15 Gy γ-rays (1Gy 3 times a week for 5 weeks) significantly decreased plasma NO level when compared with non irradiated rats. This may be explained by the study of Tishkin et al (2007) who showed that whole body gamma irradiation induced endothelium dysfunction by suppressing calcium-activated potassium channels in rats which control the driving force for Ca2+ entry and therefore Ca2+ dependent NO synthesis in endothelial cells.…”