Advanced search
Start date
Betweenand


Metho of quantification of nucleotides by HPLC-MS/MS and evaluation of the activity of sildenafil analoges in phosphodiesterase

Full text
Author(s):
Raquel Lorenzetti
Total Authors: 1
Document type: Doctoral Thesis
Press: Campinas, SP.
Institution: Universidade Estadual de Campinas (UNICAMP). Faculdade de Ciências Médicas
Defense date:
Examining board members:
Gilberto De Nucci; Darcio Gomes Pereira; Eros Antonio de Almeida; Stephen Hyslo; Silvia Lacchini
Advisor: Gilberto De Nucci
Abstract

In the present work a new method for the dosage of the activity of phosphodiesterase was standardized in vitro, for HPLC-MS/MS. This new method obtained to present exactness, precision, sensitivity, and rapidity in the analyses; monitoring the nucleotides (AMP, GMP, cAMP and cGMP). The development of new drug derived from an archetype points with respect to the molecule attainment with one better pharmacokinetic profile or one better relation structure-activity. Currently the sildenafil is considered the main drug for the treatment of erectile dysfunction. In this work, we evaluate new analogous called composites of sildenafil (carbonate of lodenafil, dimer urea and dimer uretana). The analogous ones had been analyzed how much the activity in PDE5 and platelet aggregation human being, in vitro. The stability of these composites was determined, in human acid way and plasma, in vitro, beyond its possible metabolites in microsomes and hepatocytes of rat in vitro, and its pharmacokinetic profile after intravenous and oral, in dog, in vivo. The results had shown that the analogous of sildenafil inhibit the activity of PDE and they do not inhibit the platelet aggregation in a similar way that the sildenafil in vitro, however potencializam the action of the giver of NO (SNP). The analogous ones of sildenafil are presented steady in human acid way and plasma. In the metabolization assay, metabolization of dimer urea and dimer uretana was not observed, however the lodenafil carbonate was metabolizado mainly in lodenafil, in vitro. The lodenafil carbonate quickly is biotransformation in lodenafil, after administration v.i. and v.o. in dog. We conclude that this work presents a new method for analyze activity of PDEs and a new therapeutically perspective for the erectile dysfunction, represented for lodenafil carbonate, which inhibits concentration-dependent the activity of PDE5 (AU)