Inhibition of Nav1.7 channel by a novel blocker QLS-81 for alleviation of neuropathic pain.

Voltage-gated sodium channel Nav1.7 robustly expressed in peripheral nociceptive neurons has been considered as a therapeutic target for chronic pain, but there is no selective Nav1.7 inhibitor available for therapy of chronic pain.

Effect of matrine on human ether à go-go related gene (HERG) channels expressed in Chinese hamster ovary cells.

Objective: To observe the effect of matrine on human ether à go-go related gene (HERG) potassium channels expressed in Chinese hamster ovary (CHO) cells and investigate whether HERG channel is a new target of the pharmacological effect of matrine on arrhythmia and tumor

Methods: HERG channel potassium current in CHO cell was recorded using whole-cell patch-clamp technique, and the influence of matrine on the current was explored.

Results: Matrine inhibited HERG potassium current in a dose-dependent manner, and the 50% inhibitory concentration (IC IC(50)) was 411±23 μmol/L. Matrine had no significant effect on the activation kinetics, and mainly blocked HERG channels in their closed state.

[Effects of telmisartan on voltage-gated Kv1.3 and Kv1.5 potassium channels expressed in Xenopus oocytes].

Objective: To observe the effects of telmisartan on Kv1.3 and Kv1.5 potassium channels expressed in Xenopus oocytes.

High extracellular potassium ion concentration attenuates the blockade action of ketanserin on Kv1.3 channels expressed in xenopus oocytes.

Background: Ketanserin (KT), a selective serotonin (5-HT) 2-receptor antagonist, reduces peripheral blood pressure by blocking the activation of peripheral 5-HT receptors. In this study electrophysiological method was used to investigate the effect of KT and potassium ion on Kv1.3 potassium channels and explore the role of blocker KT in the alteration of channel kinetics contributing to the potassium ion imbalances.

Quercetin activates human Kv1.5 channels by a residue I502 in the S6 segment.

1. The aims of the present study were to investigate the pharmacological effects of quercetin on wild-type (WT) and mutant (I502A) human (h) Kv1.5 channel currents (I(kur)) and to identify whether mutation in the S6 segment is critical to activation of I(kur) by quercetin.

Blockade of the human ether-a-go-go-related gene potassium channel by ketanserin.

In the present study, we investigated the inhibitory action of ketanserin on wild-type (WT) and Y652 mutant human ether-a-go-go-related gene (HERG) potassium channels expressed in Xenopus oocytes and the effects of changing the channel molecular determinants characteristics on the blockade with and without ketanserin intervention using standard two-microelectrode voltage-clamp techniques. Point mutations were introduced into HERG gene (Y652A and Y652R) and subcloned into the pSP64 plasmid expression vector. Complementary RNAs for injection into oocytes were prepared with SP6 Cap-Scribe after linearization of the expression construct with EcoR I.

[The persistent expression of HERG channel in Xenopus oocyte and alteration of current].

Aim: To explore a method of the stable and persistent expression of HERG(human ether-a-go-go-related gene) channels in Xenopus oocytes, and investigate the alteration of rest membrane potential of oocytes and electrophysiological properties of expressed channel in different culture duration.

Methods: HERG mRNA for injection was prepared with in intro transcription using vector plasmid pSP64 containing HERG cDNA fragment. Expressed HERG current was recorded using standard two-microelectrode voltage-clamp technique.

Electropharmacological properties of telmisartan in blocking hKv1.5 and HERG potassium channels expressed on Xenopus laevis oocytes.

Aim: The objectives of this study were to investigate the inhibitory action of telmisartan, a selective angiotensin II type 1 receptor antagonist, on hKv1.5 and human ether-a-go-go-related gene (HERG) channels expressed on Xenopus laevis oocytes.

Methods: hKv1.