Fosfodiesterase isoforma tipo 5 na síndrome de pré-eclâmpsia

Abstract

Introduction: Phosphodiesterase is a cyclic nucleotide responsible for the hydrolysis of cyclic adenosine 3 ', 5'-monophosphate and / or cyclic guanosine monophosphate, which is important for clinical aspects. Phosphodiesterase activity is elevated in the serum of patients with Pre-Eclampsia Syndrome (SPE). This complex multisystemic syndrome remains with unknown etiology, its mechanisms are related to endothelial dysfunction and it covers a considerable fraction of pregnant women in the world. Objectives: In pregnant women with or without SPE: a) to compare the concentration of PDE5 protein in maternal plasma; b) to compare PDE5 enzymatic activity in the placenta; c) to compare placenta PDE5 mRNA expression. Methodology: Case-control study including 151 pregnant (100 controls and 51 with SPE). The concentration of PDE5 in maternal plasma was evaluated with an Enzyme Immunoadsorption Assay, enzymatic activity in the placenta was performed using a colorimetric assay and placental expression by qRT-PCR. Results: The concentration of PDE5 in maternal plasma was not different between groups (GC: 0.11 ± 0.04 ng / mL, SPE: 0.11 ± 0.01 ng / mL, p = 0.307, t Student). However, the expression of PDE5 in placental tissue was 1,125 times higher in SPE group (p> 0.001), with 0.1 being the minimum value and 5,454.9 being the maximum. The enzymatic activity of PDE was similar between groups (GC: 0.41 ± 0.28, SPE: 0.42 ± 0.26 nmol, p = 0.955, Mann Whitney test). Conclusion: Increased levels of PDE5 found in placenta may represent a pathophysiological event or adaptive phenomenon. Considering the normal levels of the enzyme in SPE plasma and high expression in placentas of the same group - it is suggested that the placenta plays a central role in SPE physiology. The alterations associated with PDE5 in SPE suggest that this enzyme has a relevant role in the pathophysiological processes associated with the vasoconstriction presented by these women.