Quercetin-filled phosphatidylcholine liposomes restore abnormalities in rat thoracic aorta BK(Ca) channel function following ionizing irradiation.
- Author:
Anatoly SOLOVIEV
1
;
Sergey TISHKIN
;
Sergey KYRYCHENKO
Author Information
1. Institute of Pharmacology and Toxicology, Academy of Medical Science, Kiev, Ukraine. tonysolpharm@ukrpost.ua
- Publication Type:Journal Article
- MeSH:
Animals;
Aorta, Thoracic;
drug effects;
radiation effects;
Large-Conductance Calcium-Activated Potassium Channels;
physiology;
Liposomes;
chemistry;
Myocytes, Smooth Muscle;
physiology;
Patch-Clamp Techniques;
Phosphatidylcholines;
chemistry;
Quercetin;
pharmacology;
Radiation, Ionizing;
Rats
- From:
Acta Physiologica Sinica
2009;61(3):201-210
- CountryChina
- Language:English
-
Abstract:
The goal of the present study was to investigate the effects of quercetin-filled phosphatidylcholine liposomes (PCL-Q) on the currents carried by large conductance Ca(2+)-dependent K(+) channels (BK(Ca)) in rat thoracic aorta following non-fatal whole-body ionizing irradiation. Using patch-clamp technique, it is found that the outward K(+) currents of isolated smooth muscle cells (SMCs) stimulated by depolarizing voltage steps were sensitive to BK(Ca) inhibitor, paxilline, and this kind of outward K(+) currents in SMCs from irradiated animals demonstrated a significant decrease in amplitude. Radiation-induced BK(Ca) suppression was evident 9 days post-irradiation and progressively increased over 30 days of experimental period. Thus, the vasorelaxing force of these SMCs may be diminished following irradiation. PCL-Q effectively restored BK(Ca) function in post-irradiated SMCs. It is noteworthy that the constituents of PCL-Q, i.e., free quercetin (Q) and "empty" liposomes (PCL), being taken separately, showed a decreased ability to recover BK(Ca) function as compared with combined composition. These results suggest that PCL-Q is able to regain normal function of BK(Ca) following irradiation. The protective effects of PCL-Q can be explained by its antioxidant and membrane repairing properties as well as its ability to inhibit protein kinase C activity. Thus, the lipid encapsulation of flavonoid, PCL-Q, appears to be a potential medication in the case of ionizing irradiation accident, and for the patients with neoplasm who have to receive external radiotherapy as well.
