Browsing by Author "Borges, Gabriel Silva Marques"

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    Cardiovascular responses to L-glutamate microinjection into the NTS are abrogated by reduced glutathione.
    (2017) Granato, Álisson Silva; Gomes, Paula Magalhães; Sá, Renato Willian Martins; Borges, Gabriel Silva Marques; Alzamora, Andréia Carvalho; Oliveira, Lisandra Brandino de; Toney, Glenn M.; Cardoso, Leonardo Máximo
    Redox imbalance in regions of the CNS controlling blood pressure is increasingly recognized as a leading factor for hypertension. Nucleus tractus solitarius (NTS) of the dorsomedial medulla is the main region receiving excitatory visceral sensory inputs that modulate autonomic efferent drive to the cardiovascular system. This study sought to determine the capacity of reduced glutathione, a major bioactive antioxidant, to modulate NTS-mediated control of cardiovascular function in unanaesthetized rats. Male Fischer 344 rats were used for microinjection experiments. Cardiovascular responses to l-glutamate were first used to verify accurate placement of injections into the dorsomedial region comprising the NTS. Next, responses to GSH or vehicle were recorded followed by responses to l-glutamate again at the same site. GSH microinjection increased mean arterial pressure (MAP) compared to vehicle and abrogated responses to subsequent injection of l-glutamate. These data indicate that GSH microinjection into the NTS affects blood pressure regulation by dorsomedial neuronal circuits and blunts l-glutamate driven excitation in this region. These findings raise the possibility that increased antioxidant actions of GSH in NTS could contribute to autonomic control dysfunctions of the cardiovascular system.
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    Chemoreflex control of the cardiovascular system remains altered after recovery from low protein diet early in life.
    (2014) Sá, Renato Willian Martins; Borges, Gabriel Silva Marques; Chianca Júnior, Deoclécio Alves; Oliveira, Lisandra Brandino de; Cardoso, Leonardo Máximo
    This study aimed to evaluate the cardiovascular component of the arterial chemoreflex in rats recovered from low protein diet. Male Fischer rats were randomly divided into control and recovered (R-PR) groups after weaning. R-PR rats were fed with low protein diet for 35 days and recovered under normal protein diet for 70 days. Control rats received normal protein diet for 105 days. Arterial chemoreflexwas elicited by intravenous injection of KCN. Results showed that pressor response of the chemoreflex was increased in R-PR. Data suggest that protein restriction may alter cardiovascular response to chemical activation of the chemoreflex after recovery.