Internal Aluminum Block of Plant Inward K+ Channels

Internal aluminum block of plant inward K(+) channels.

Aluminum (Al) inhibits inward K(+) channels (K(in)) in both root hair and guard cells, which accounts for at least part of the Al toxicity in plants. To understand the mechanism of Al-induced K(in) inhibition, we performed patch clamp analyses on K(in) in guard cells and on KAT1 channels expressed in Xenopus oocytes. Our results show that Al inhibits plant K(in) by blocking the channels at the ...

Physiological Roles of Inward-Rectifying K+ Channels.

Silent inward rectifier K+ channels in hypercholesterolemia.

Hypercholesterolemia is an independent risk factor for development of cardiovascular disease1 and has been demonstrated to impair endothelium-dependent and independent vasodilatation.2 However, the mechanisms responsible for changes in vascular reactivity and impaired blood flow regulation induced by hypercholesterolemia remain unclear. Previous studies in cultured endothelial cells have shown ...

Block of inward rectifying K+ channels (KIR) inhibits bradykinin-induced vasodilatation in human forearm resistance vasculature.

OBJECTIVE To investigate the possible involvement of inward rectifying K(+) channels (K(IR)) in the response of human resistance vessels to bradykinin in vivo. METHODS AND RESULTS Drugs were administered via the brachial artery in healthy male volunteers and forearm blood flow was measured by venous occlusion plethysmography. Inhibition of K(IR) by barium chloride (4 micromol min(-1)) alone o...

Revisiting inward rectification: K ions permeate through Kir2.1 channels during high-affinity block by spermidine

Outward currents through Kir2.1 channels play crucial roles in controlling the electrical properties of excitable cells, and such currents are subjected to voltage-dependent block by intracellular Mg(2+) and polyamines that bind to both high- and low-affinity sites on the channels. Under physiological conditions, high-affinity block is saturated and yet outward Kir2.1 currents can still occur, ...