Negative feedback regulation of vasocontraction by potassium channels in 10‐ to 15‐day‐old rats: Dominating role of K_v7 channels

Abstract

The negative feedback regulation of vasocontraction by potassium channels varies during maturation depending on the channel type. A dominating contribution of K 7 channels to the regulation of basal tone and agonist-induced contraction was observed in arteries of 10- to 15-day-old animals.

Pro‐contractile role of chloride in arterial smooth muscle: Postnatal decline potentially governed by sympathetic nerves

“…According to our previous observations, this includes a postnatal decline of the smooth muscle contractile apparatus sensitivity to Ca 2+ (Puzdrova et al, 2014) and the contribution of Rhokinase to the contraction (Mochalov et al, 2018), and a decreased role of K + channels in the contractile responses (Shvetsova, Gaynullina, Tarasova, & Schubert, 2018). Of note, despite the increased influence of K + permeability, the resting membrane potential of smooth muscle is not changed or is even slightly more positive in arteries from neonatal compared with adult rats (Sandow, Goto, Rummery, & Hill, 2004;Shvetsova et al, 2018). This suggests that the homeostasis of other ions controlling the smooth muscle membrane potential and, therefore, arterial tone is also affected during postnatal development,…”

Vasodilation of rat skeletal muscle arteries by the novel BK channel opener GoSlo is mediated by the simultaneous activation of BK and Kv7 channels

“…This idea was based on the fact that K v 7 channels are well‐known to be expressed in a large variety of vascular smooth muscle and to be involved in vasoconstriction and vasodilation (see recent reviews of Barrese, Stott, & Greenwood, ; Byron & Brueggemann, ; Haick & Byron, ; Tykocki, Boerman, & Jackson, ). In particular, transcriptional expression of K v 7 channel genes and their involvement in the regulation of vessel contractility has been shown for rat mesenteric (Jepps et al, ; Jepps, Carr, Lundegaard, Olesen, & Greenwood, ; Yeung et al, ), Gracilis muscle (Zavaritskaya et al, ), and saphenous (Shvetsova, Gaynullina, Tarasova, & Schubert, ) arteries. We confirmed the previous findings regarding the transcriptional expression of K v 7 genes using an alternative approach, digital PCR, reproducing our previous data that in rat Gracilis muscle arteries, like in many other arteries (see recent reviews of Barrese, Stott, & Greenwood, ; Byron & Brueggemann, ; Haick & Byron, ; Tykocki, Boerman, & Jackson, ), both KCNQ4 and KCNQ5 channel genes showed higher levels of expression than the other KCNQs.…”

“…(e) currents obtained from a different cell, held at −80 mV and stepped from −100 to +50 mV in 10-mV increments, in the absence and presence of GoSlo-SR-5-130 (10 −5 M), respectively. Tail current deactivation increased from 26 ± 4 ms to 46 ± 4 ms following a repolarisation from +40 to −120 mV (n = 5; P < .05; paired t test); (f) summary activation curves obtained from five cells in the absence (open circles) and presence (pink circles) of GoSlo-SR-5-130 Greenwood, 2015;Yeung et al, 2007), Gracilis muscle (Zavaritskaya et al, 2013), and saphenous (Shvetsova, Gaynullina, Tarasova, & Schubert, 2019) arteries. We confirmed the previous findings regarding the transcriptional expression of K v 7 genes using an alternative approach, digital PCR, reproducing our previous data that in rat…”

TASK‐1 channel blockade by AVE1231 increases vasocontractile responses and BP in 1‐ to 2‐week‐old but not adult rats

“…Approval for the use of laboratory animals and all procedures used in this study was granted by German and Russian institutional committees on animal welfare (I-17/17 and 93-g, respectively). Rats have been used for research on potassium channel function in early postnatal ontogenesis in many studies (Belevych, Beck, Tammaro, Poston, & Smirnov, 2002;Gollasch et al, 1998;Shvetsova et al, 2019). Since the male body is not subjected to cyclical hormonal changes, we decided to employ a commonly used approach, namely, to explore a novel physiological mechanism only in males.…”

“…Recently, we showed that in rat saphenous arteries in the early postnatal period, the negative feedback regulation of vasocontraction by BKCa channels was small, but the influence of Kv1, Kir, and Kv7 channels was quite pronounced compared with adult animals (Shvetsova, Gaynullina, Tarasova, & Schubert, 2019).…”