Postnatal maturation attenuates the impact of Kv7 channels on smooth muscle membrane potential and contractility in rat arteriesстатьяЭлектронная публикацияТезисы
Статья опубликована в журнале из списка Web of Science и/или Scopus
Дата последнего поиска статьи во внешних источниках: 27 января 2018 г.
Аннотация:Objectives. Vascular smooth muscle Kv7 potassium channels contribute considerably to agonist and pressure-induced vasoconstriction and to vasodilation induced by various substances. Notably, potassium channel function has been shown to be altered during postnatal ontogenesis. However, the role of Kv7 channels to this process has not been studied yet. We tested the hypothesis that the impact of Kv7 channels in counteracting vasocontractile responses changes with maturation.Materials and Methods. All experiments were performed on endothelium-denuded saphenous arteries from young (10-15-day) and adult (2-3-month) male rats. Isometric force and membrane potential (MP) were recorded simultaneously using wire myography and the sharp microelectrode technique. The functional role of Kv7 channels was studied using the specific inhibitor XE991 (3 microM). Kv7 channel subunit expression was determined by qPCR.Results. In adult arteries XE991 caused a small depolarization (9 mV), not associated with tone development. In contrast, in young arteries strong depolarization (25mV) and basal tone development were observed in response to XE991. Moreover, XE991induced a potentiation of the depolarization and the contractile response evoked by the α1-adrenoceptor agonist methoxamine. This effect was more prominent in young compared to adult arteries. Resting MP levels did not differ between the two age groups. In addition, a higher abundance of Kcnq1, Kcnq2, Kcne2, Kcne3 and Kcne4 mRNA was observed in arteries of young rats.Conclusions. The contribution of Kv7 channels to the regulation of contractile responses of rat saphenous arteries is stronger in early postnatal ontogenesis.Supported by RFBR (grant N16-04-01395) and DAAD (Short-Term Grants, 2016).