Mieloperoxidase em síndromes hipertensivas da gestação
Carregando...
Data
2017-02-21
Autores
Penha, Lilliam Rocha [UNESP]
Título da Revista
ISSN da Revista
Título de Volume
Editor
Universidade Estadual Paulista (Unesp)
Resumo
A enzima mieloperoxidase (MPO) é caracterizada por produzir substâncias altamente reativas e é reconhecida por desencadear estresse oxidativo e disfunção endotelial mediada, em parte, pela interferência com o vasodilatador óxido nítrico. Neste estudo, nós investigamos a relação entre o óxido nítrico e a MPO in vitro incubando o plasma de gestantes saudáveis, hipertensas e com pré-eclâmpsia com células endoteliais (HUVEC). Foram observados maiores níveis de MPO no sobrenadante de células incubadas com o plasma de pacientes com pré-eclâmpsia comparado ao de células incubadas com plasma de gestantes saudáveis, e que a inibição da atividade enzimática aumentou a disponibilidade de óxido nítrico. Posteriormente, nós avaliamos a concentração e atividade da MPO no plasma de 219 gestantes saudáveis, 130 hipertensas gestacionais (com e sem terapia anti-hipertensiva) e 143 gestantes com pré-eclâmpsia (com e sem terapia anti-hipertensiva). Nós observamos que pacientes com síndromes hipertensivas e sob tratamento anti-hipertensivo apresentaram menores níveis e atividade desta enzima e, curiosamente, pacientes que tiveram o plasma coletado antes do tratamento anti-hipertensivo apresentaram níveis elevados de MPO. Nossos resultados indicam um elevado risco cardiovascular em gestantes com síndromes hipertensivas e que a MPO ativa pode ter um papel na disfunção endotelial nestas síndromes pelo comprometimento da disponibilidade do óxido nítrico. Além disso, o uso de drogas anti-hipertensivas parece reduzir os níveis e a atividade enzimática, sugerindo um novo mecanismo protetor para estas drogas.
Myeloperoxidase is characterized by production of highly reactive substances and recognized to trigger oxidative stress and endothelial dysfunction meditated in part by nitric oxide impairment. In this study, we investigated the relation between nitric oxide and MPO in vitro incubating plasma from healthy, gestational hypertensive and preeclampsia with endothelial cells. We found higher levels of myeloperoxidase in cultures incubated with plasma from preeclampsia group compared to healthy pregnant, and the inhibition of MPO activity improved nitric oxide bioavailability. Further, we measured plasma concentration and activity of myeloperoxidase in 219 healthy pregnant women, 130 gestational hypertension (on antihypertensive therapy or not) and 143 preeclampsia patients (on antihypertensive therapy or not). We found that patients with hypertensive disorders and on antihypertensive treatment showed lower levels and activity of this enzyme and interestingly patients who the plasma was collected before antihypertensive treatment showed elevated levels of MPO. Our results indicate a higher cardiovascular risk in pregnant with hypertensive disorders, and that active myeloperoxidase may play a role in the endothelial dysfunction in this conditions by impairment of nitric oxide availability. Besides, the use of antihypertensive drugs seems to decrease enzyme levels and activity suggesting a new protective mechanism for these drugs.
Myeloperoxidase is characterized by production of highly reactive substances and recognized to trigger oxidative stress and endothelial dysfunction meditated in part by nitric oxide impairment. In this study, we investigated the relation between nitric oxide and MPO in vitro incubating plasma from healthy, gestational hypertensive and preeclampsia with endothelial cells. We found higher levels of myeloperoxidase in cultures incubated with plasma from preeclampsia group compared to healthy pregnant, and the inhibition of MPO activity improved nitric oxide bioavailability. Further, we measured plasma concentration and activity of myeloperoxidase in 219 healthy pregnant women, 130 gestational hypertension (on antihypertensive therapy or not) and 143 preeclampsia patients (on antihypertensive therapy or not). We found that patients with hypertensive disorders and on antihypertensive treatment showed lower levels and activity of this enzyme and interestingly patients who the plasma was collected before antihypertensive treatment showed elevated levels of MPO. Our results indicate a higher cardiovascular risk in pregnant with hypertensive disorders, and that active myeloperoxidase may play a role in the endothelial dysfunction in this conditions by impairment of nitric oxide availability. Besides, the use of antihypertensive drugs seems to decrease enzyme levels and activity suggesting a new protective mechanism for these drugs.
Descrição
Palavras-chave
Pré-eclâmpsia, Hipertensão gestacional, Mieloperoxidase, Óxido nítrico, Drogas anti-hipertensivas, Preeclampsia, Gestational hypertension, Myeloperoxidase, Nitric oxide, Antihypertensive drugs