Evaluation of Biological Activity Exerted by Dibenzo[b,e]Thiophene-11(6H)-One on Left Ventricular Pressure Using an Isolated Rat Heart Model.

BACKGROUND: Some studies show that some Dibenzo derivatives can produce changes in the cardiovascular system; however, its molecular mechanism is not very clear.

OBJECTIVE: The objective of this investigation was to evaluate the inotropic activity of ten Dibenzo derivatives (compounds 1 to 10) on either perfusion pressure or left ventricular pressure.

METHODS: Biological activity produced by the Dibenzo derivatives on either perfusion pressure or coronary resistance was evaluated using an isolated rat heart. In addition, the molecular mechanism of biological activity produced by compound 4 (Dibenzo[b,e]thiophene-11(6H)-one) on left ventricular pressure was determined using both Bay-k8644 and nifedipine as pharmacological tools in an isolated rat heart model.

RESULTS: The results showed that Dibenzo[b,e]thiophene-11(6H)-one increases perfusion pressure and coronary resistance at a dose of 0.001 nM. Besides, other data display that Dibenzo[b,e]thiophene-11(6H)-one increases left ventricular pressure in a dose-dependent manner (0.001 to 100 nM) and this effect was similar to biological activity produced by Bay-k8644 drug on left ventricular pressure. However, the effect exerted by Dibenzo[b,e]thiophene-11(6H)-one was inhibited in the presence of nifedipine at a dose of 1 nM.

CONCLUSIONS: All these data suggest that Dibenzo[b,e]thiophene-11(6H)-one increase left ventricular pressure through calcium channel activation. In this way, Dibenzo[b,e]thiophene-11(6H)-one could be a good candidate as positive inotropic agent to heart failure.