Voltage-dependent inward currents in smooth muscle cells of skeletal muscle arterioles.

Voltage-dependent inward currents responsible for the depolarizing phase of action potentials were characterized in smooth muscle cells of 4th order arterioles in mouse skeletal muscle. Currents through L-type Ca2+ channels were expected to be dominant; however, action potentials were not eliminated in nominally Ca2+-free bathing solution or by addition of L-type Ca2+ channel blocker nifedipine (10 μM). Instead, Na+ channel blocker tetrodotoxin (TTX, 1 μM) reduced the maximal velocity of the upstroke at low, but not at normal (2 mM), Ca2+ in the bath.

Two-year follow-up of percutaneous coronary intervention using EucaTax or Cypher.

Background: The EucaTax stent (EUPES) is a coronary stent with biodegradable polymer and camouflage coating that has been developed to promote the complete elution of drugs and decrease the risk of late complications. The aim of this study was to evaluate the efficacy and safety of the double-coated EUPES in patients with stable angina versus sirolimus-eluting stent CYPHER (SES) with permanent polymer coating.

Methods And Materials: The study included consecutive patient with at least 70% de novo coronary lesions in one or two native coronary arteries and who had undergone the coronary stenting using either EUPES or SES.

Ca2+-dependent inactivation of CaV1.2 channels prevents Gd3+ block: does Ca2+ block the pore of inactivated channels?

Lanthanide gadolinium (Gd(3+)) blocks Ca(V)1.2 channels at the selectivity filter. Here we investigated whether Gd(3+) block interferes with Ca(2+)-dependent inactivation, which requires Ca(2+) entry through the same site.

Block of CaV1.2 channels by Gd3+ reveals preopening transitions in the selectivity filter.

Using the lanthanide gadolinium (Gd(3+)) as a Ca(2+) replacing probe, we investigated the voltage dependence of pore blockage of Ca(V)1.2 channels. Gd(+3) reduces peak currents (tonic block) and accelerates decay of ionic current during depolarization (use-dependent block).

Role of extracellular Ca2+ in gating of CaV1.2 channels.

We examined changes in ionic and gating currents in Ca(V)1.2 channels when extracellular Ca(2+) was reduced from 10 mm to 0.1 microm.

Modulation of the voltage sensor of L-type Ca2+ channels by intracellular Ca2+.

Both intracellular calcium and transmembrane voltage cause inactivation, or spontaneous closure, of L-type (CaV1.2) calcium channels. Here we show that long-lasting elevations of intracellular calcium to the concentrations that are expected to be near an open channel (>/=100 microM) completely and reversibly blocked calcium current through L-type channels.

Functional characterization of nitric oxide and YC-1 activation of soluble guanylyl cyclase: structural implication for the YC-1 binding site?

Soluble guanylyl cyclase (sGC) is a heterodimeric enzyme formed by an alpha subunit and a beta subunit, the latter containing the heme where nitric oxide (NO) binds. When NO binds, the basal activity of sGC is increased several hundred fold. sGC activity is also increased by YC-1, a benzylindazole allosteric activator.