Pharmacological profile of LAS 31180, a new inotropic/vasodilator quinolone derivative

LAS 31180 (3-methylsulphonylamino-1-methyl-4(1H)-quinolone, CAS 137338-43-3 ) was found to have positive inotropic and vasodilator properties through i ts inhibitory action on type 3 phosphodiesterase. The inotropic effects of LAS 31180 were demonstrated in vitro both in isolated guinea-pig ventricula r strips (EC50 Of 1.2 mu mol/l) and in isolated guinea-pig working hearts. In conscious chronically instrumented Beagle dogs, LAS 31180 administered e ither by intravenous or oral route, showed a dose-dependent, long-lasting p ositive inotropic effect with minimal effects on heart rate. In hypertensiv e Beagle dogs LAS 31180 elicited a potent and long-lasting fall in blood pr essure.