ИСТИНА

The contribution of Kv7 and Kir channels to the regulation of contractile responses of peripheral arteries and membrane potential of arterial smooth muscle decreases with maturation. The role of TASK-1 (TWIK-related acid-sensitive)potassium channels to maturation hasn’t been studied in arteries of the peripheral circulation. We tested the hypotheses that (1) TASK-1 channels regulate contractile responses of arteries from the peripheral circulation; (2) The impact of TASK-1 channels in counteracting vasocontractile responses changes during postnatal development. We demonstrated that (1) Blockade of TASK-1 channels with AVE1231 caused the development of strong basal tone and increased MX-induced vasocontraction in arteries of young, but not adult rats, (2) The contribution of TASK-1 channels to the regulation of arterial smooth muscle membrane potential is larger in young than in adult rats, (3) Higher expression level of TASK-1 mRNA was observed in arteries from young rats. Therefore, the negative feedback regulation of vasocontraction by AVE1231-sensitive TASK-1 channels in peripheral arteries is very strong in young, but absent in adult rats. This may be important for setting low peripheral resistance and arterial blood pressure during the perinatal age.