Disease relevance of AR-L 57BS

• The equally pronounced increases in regional contractility in normal and stunned myocardium during postextrasystolic potentiation and the infusion of calcium or the calcium-sensitizing agent AR-L-57, however, suggest an unchanged calcium sensitivity in reperfused myocardium [1].
• AR-L 57 increased systolic thickening velocity at 10 min, 4 and 8 h reperfusion to a similar extent as before ischemia [2].

High impact information on AR-L 57BS

• Amrinone and AR-L57 caused concentration-dependent increases in the contractile states of either perfused guinea-pig hearts or cultured rat cardiomyocytes [3].
• It has been suggested that amrinone and AR-L57 enhance cardiac contractility either by inhibiting phosphodiesterase activity or altering Ca++ homeostasis [3].
• The equally pronounced increases in regional contractility in normal and "stunned" myocardium during postextrasystolic potentiation and the infusion of calcium or the calcium-sensitizing agent AR-L-57, however, suggest an unchanged calcium sensitivity of reperfused myocardium.(ABSTRACT TRUNCATED AT 250 WORDS)[4]
• Both AR-L57 and AR-L115 increased contractile force of cat papillary muscles in concentration-dependent manners; these effects were independent of either alpha- or beta-adrenoceptor stimulation [5].
• In anesthetized dogs, i.v. AR-L57 and AR-L115 increased contractility and heart rate while reducing mean arterial blood pressure [5].

Biological context of AR-L 57BS

• This effect and the pharmacokinetics of AR-L 57 CL have been investigated by non-invasive methods in 8 healthy volunteers [6].
• The plasma concentrations of AR-L 57 CL of 2 - 5 mug-equivalents/ml showed a highly significant correlation with the decrease in systolic time intervals [6].
• Contractility and protein phosphorylation in cardiomyocytes: effects of isoproterenol and AR-L57 [7].

Analytical, diagnostic and therapeutic context of AR-L 57BS

• After a single intravenous dose of 200 mg, administered as part of Phase 1 of the clinical studies, AR-L 57 CL plasma concentrations were measured by fluorimetry at intervals for up to one hour [6].

References