title: Chemoreflex and baroreflex alterations in Parkinsonism induced by 6-OHDA in unanesthetized rats.
abstract: Parkinson's disease (PD) is mainly characterized by motor signals. However, non-motor signals also affect and decrease the quality of life of PD patients. Among these non-motor signs are cardiovascular disorders as orthostatic hypotension, postprandial hypotension and cardiac arrhythmias, which may be due to the involvement of both central nervous system and peripheral autonomic nervous system. In the present study we investigated the cardiovascular function, evaluating cardiovascular reflexes (chemoreflex and baroreflex), in an animal model of Parkinsonism induced by bilateral infusion of the toxin 6-hydroxydopamine (6-OHDA), in the substantia nigra pars compacta (SNpc). The results showed that the animals induced to Parkinsonism had lower arterial pressure (AP) and heart rate HR) compared to control animals. We showed that after activation of the baroreceptors by phenylephrine (Phe) and sodium nitroprusside (SNP), the baroreflex sensitivity index was not changed between the groups. However, there was a greater increase in the AP when stimulated with Phe and greater tachycardia when stimulated with SNP in 6-OHDA animals. After activation of the peripheral chemoreceptors through KCN injection (cytotoxic hypoxia), there was a higher increase in pressor and bradycardic response in injured animals with bilateral 6-OHDA. These changes in the cardiovascular reflexes may be important adjustments mechanisms to maintain the cerebral blood flow in those animals, and may be a result of denervation supersensitivity to catecholamines in autonomic targets.
authors.affiliation: Department of Physiological Sciences, State University of Londrina, Londrina, PR, Brazil.
authors.forename: Deborah
authors.initials: D
authors.lastname: Ariza
authors.affiliation: Department of Physiological Sciences, State University of Londrina, Londrina, PR, Brazil.
authors.forename: Fernanda Novi Cortegoso
authors.initials: FNC
authors.lastname: Lopes
authors.affiliation: School of Pharmaceutical Sciences, State University of São Paulo-UNESP, Araraquara, SP, Brazil.
authors.forename: Carlos Cesar
authors.initials: CC
authors.lastname: Crestani
authors.affiliation: Department of Physiological Sciences, State University of Londrina, Londrina, PR, Brazil. Electronic address: martinspinge@uel.br.
authors.forename: Marli Cardoso
authors.initials: MC
authors.lastname: Martins-Pinge
mesh_terms: D000818:Animals; D017704:Baroreflex; D001794:Blood Pressure; D002628:Chemoreceptor Cells / Q000187:drug effects / Q000502:physiology*; D006339:Heart Rate; D008297:Male; D009599:Nitroprusside / Q000494:pharmacology; D016627:Oxidopamine; D020734:Parkinsonian Disorders / Q000139:chemically induced / Q000503:physiopathology*; D010656:Phenylephrine / Q000494:pharmacology; D017208:Rats, Wistar; D013378:Substantia Nigra / Q000187:drug effects / Q000503:physiopathology
chemical_list: D009599:Nitroprusside; D010656:Phenylephrine; D016627:Oxidopamine
keywords: Arterial pressure; Dysautonomia; Heart rate; Phenylephrine; Potassium cyanide; Sodium nitroprusside