The antiarrhythmic peptide analog ZP123 prevents atrial conduction slowing during metabolic stress.

Objective: As atrial conduction slowing is important in the pathogenesis of atrial reentry arrhythmias, a drug that increases atrial conduction or prevents atrial conduction slowing could serve to prevent atrial reentry arrhythmias. In this study, we investigated whether the novel stable antiarrhythmic peptide analog, ZP123, was able to prevent atrial conduction slowing.

Methods: We examined the effect of ZP123 on metabolic stress-induced changes in conduction velocity (CV) and on dynamic CV restitution in isolated left atria from male Sprague-Dawley rats.

Two conserved arginines in the extracellular N-terminal domain of the GABA(A) receptor alpha(5) subunit are crucial for receptor function.

The gamma-aminobutyric acid (GABA) binding pocket within the GABA(A) receptor complex has been suggested to contain arginine residues. The aim of this study was to test this hypothesis by mutating arginine residues potentially contributing to the formation of a GABA binding pocket. Thus, six arginines conserved in human GABA(A) receptor alpha subunits (arginine 34, 70, 77, 123, 135, and 224) as well as two nonconserved arginines (79 and 190), all located in the extracellular N-terminal segment of the alpha(5) subunit, were substituted by lysines.

Identification and cloning of a gamma 3 subunit splice variant of the human GABA(A) receptor.

cDNA sequences encoding two forms of the GABA(A) gamma 3 receptor subunit were cloned from human hippocampus. The nucleotide sequences differ by the absence (gamma 3S) or presence (gamma 3L) of 18 bp located in the presumed intracellular loop between transmembrane region (TM) III and IV. The extra 18 bp in the gamma 3L subunit generates a consensus site for phosphorylation by protein kinase C (PKC).

Intrinsic termination of T7 RNA polymerase mediated by either RNA or DNA.

Intrinsic termination of T7 RNA polymerase transcription occurs at different signals in vitro. One type of signal is similar to that mediating factor-independent termination of Escherichia coli RNA polymerase, whereas the other type does not involve RNA hairpin formation. By examining the termination behaviour of T7 RNA polymerase at the E.