ABSTRACT
BACKGROUND: Controversy exists regarding the role of the subfractions of high-density lipoproteins (HDL2 and HDL3) in cardiovascular disease. The functionality of these particles, and their protective role, is due in part to the paraoxonase 1 (PON1) presence in them. The polymorphisms rs662 (Q192R, A/G), rs854560 (L55 M, T/A), and rs705379 (C-108T) of the PON1 gene have been related to enzyme activity and, with the anti-oxidative capacity of the HDL. The objective was to determine the arylesterase PON1 activity in HDL3 and HDL2 and its relationship with the polymorphisms mentioned, in a young population. METHODS: The polymorphisms were determined through mini-sequencing (SnaPshot). The HDL subpopulations were separated via ionic precipitation, cholesterol was measured with enzymatic methods, and PON1 activity was measured through spectrophotometry. RESULTS: The results show that the PON1 polymorphisms do not influence the cholesterol in the HDL. A variation between 40.02 and 43.9 mg/dL was in all the polymorphisms without significant differences. Additionally, PON1 activity in the HDL3 subfractions was greater (62.83 ± 20 kU/L) than with HDL2 (35.8 ± 20.8 kU/L) in the whole population and in all the polymorphisms (p < 0.001), and it was independent of the polymorphism and differential arylesterase activity in the Q192R polymorphism (QQ > QR > RR). Thus, 115.90 ± 30.7, 88.78 ± 21.3, 65.29 ± 10.2, respectively, for total HDL, with identical behavior for HDL3 and HDL2. CONCLUSIONS: PON1 polymorphisms do not influence the HDL-c, and the PON activity is greater in the HDL3 than in the HDL2, independent of the polymorphism, but it is necessary to delve into the functionality of these findings in different populations.
ABSTRACT
Introducción. Al convertir dopamina en norepinefrina la dopamina β-hidroxilasa (DβH) regula el tono dopaminérgico y adrenérgico. Los alelos rs1989787, rs1611115 y rs1108580 del gen DβH se asocian con actividad deficiente de la enzima y por eso evaluamos sus influencias sobre variables cardiovasculares clínicas, bioquímicas y farmacológicas. Métodos: A 44 voluntarios sanos con los haplotipos triple homocigoto nativo (CC/CC/AA), triple heterocigoto (CT/CT/AG), doble homocigoto mutado (TT/CC/GG) y homocigoto mutado para el rs1611115 (CC/TT/AA) les medimos presión arterial sistólica (PAS), presión arterial diastólica (PAD) y frecuencia cardíaca (FC) en posición decúbito, sentado, de pie, bajo estímulo de frío, con la maniobra de Valsalva y post ingestión de clonidina; adicionalmente medimos actividad enzimática por espectrofotometría y concentraciones séricas de dopamina y norepinefrina por ELISA. Resultados: Edad promedio 21,6±3,5 años, 54,5 porciento mujeres. No hubo diferencias de PAS, PAD y FC obtenidas bajo diferentes condiciones; sólo encontramos cambios significativos en los descensos de la PAS y la PAD postingestión de clonidina. No hubo relación de las variables clínicas, bioquímicas y farmacológicas mencionadas con los alelos rs1989787 y rs1108580, pero los portadores del alelo mutado T del rs1611115 sí tenían frecuencias cardíacas estadísticamente inferiores a los portadores del alelo nativo C. La actividad enzimática y las concentraciones de dopamina y norepinefrina no se correlacionaron con las variables cardiovasculares, pero se encontró correlación directa entre la actividad de la enzima y las concentraciones de norepinefrina. Conclusión: El polimorfismo -970C>T del gen DβH es el único asociado con menores frecuencias cardíacas en portadores del alelo mutado T.
Introduction. To the converting dopamine in norepinephrine the enzymedopamine β-hydroxylase (DβH) regulates dopaminergic and adrenergictone. The alleles rs1989787, rs1611115 and rs1108580 of the gene DβH areassociated with deficient activity of the enzyme and thus the influence ofthese SNPs in clinical, biochemical and pharmacological variables relatedwith the cardiovascular system was evaluated. Methods: 44 healthy volunteerswith homozygous triple native (CC/CC/AA), triple heterozygous (CT/CT/AG), double mutated homozygous (TT/CC/GG) and mutated homozygoushaplotypes for the rs1611115 (CC/TT/AA) were subjected to measurementsof systolic blood pressure (SBP), diastolic blood pressure (DBP) and heart rate(HR) in the positions prone, sitting, standing, under cold stimulus, with theValsalva maneuver and after clonidine ingestion; additionally the enzymaticactivity of the DβH and the concentrations of dopamine and norepinephrinewere determined by spectrophotometry and ELISA, respectivelly. Results: Theaverage age of the group was 21.6±3.5 years, and 54.5% were women. Therewere no differences in SBP, DBP and HR obtained under different conditions;we only found significant changes in SBP and DBP decrease after clonidineingestion. There were no associations between clinical, biochemical andpharmacological variables with the rs1989787 and rs1108580 alleles, however,carriers of the mutant allele T of the rs1611115 had heart rates statisticallylower than the native C allele carriers. Neither enzymatic activity nor dopamineand norepinephrine levels were correlated with cardiovascular variables, but adirect correlation between enzyme activity and norepinephrine concentrationswas found. Conclusion: The-970C>T polymorphism of DβH gene is the onlyone associated with lower heart rates in carriers of the mutated allele T.
