Abstract

L. Figueroa-Valverde*, F. Díaz-Cedillo, E. Diaz-Ku and A. Camacho-Luis

Experimental studies suggest that pregnenolone can regulate blood pressure. Nevertheless, there is scarce information about the effects of pregnenolone and its derivatives at cardiovascular level. In addition, to date the cellular site and mechanism of action of pregnenolone at cardiovascular level is also unclear. In order, to clarify on those phenomena, we evaluated the effects of pregnenolone and hemisuccinate of pregnenolone on perfusion pressure in isolated rat heart using Langendorff flow model. Our results demonstrated that pregnenolone-derivative (10-9 M) significantly increase the perfusion pressure (p = 0.005) and vascular resistance (p = 0.006) in isolated heart. The activity exerted by hemisuccinate of pregnenolone on perfusion pressure (10-9 to 10-4 M) was blocked in presence of indomethacin (10-6 M) and montelukast (10-6 M).These data suggest that activity induced by hemisuccinate of pregnenolone on perfusion pressure and vascular resistance is dependent upon its chemical structure. This phenomenon possibly involves the thromboxane A2 (TXA2) synthesis and secretion.