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Baroreflex impairment in a rat model of Parkinson's disease
Author(s) -
Cavalleri Marina,
Barna Barbara,
Moreira Thiago,
Takakura Ana
Publication year - 2015
Publication title -
the faseb journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.709
H-Index - 277
eISSN - 1530-6860
pISSN - 0892-6638
DOI - 10.1096/fasebj.29.1_supplement.648.9
Subject(s) - baroreflex , substantia nigra , striatum , tyrosine hydroxylase , medicine , phenylephrine , endocrinology , anesthesia , dopamine , hyperreflexia , parkinson's disease , heart rate , dopaminergic , blood pressure , disease
Parkinson's disease (PD) exhibit motor and non‐motor symptoms. Among non‐motor symptoms, the cardiovascular autonomic dysfunction is frequently. The aim of this work was to evaluate whether in a model of PD induced by injection of the toxin 6‐hydroxy‐dopamine (6‐OHDA) into the striatum was able to produce changes in the baroreflex as well as in neurons in brainstem areas enrolled in cardiovascular control. Wistar rats (300‐320 g, n = 5) received bilateral injections of 6‐OHDA or vehicle into the striatum. After 60 days,baroreflex was assessed by determining the heart rate (HR) responses to ramped infusions of phenylephrine (PE) and sodium nitroprusside (SNP)induced mean arterial pressure (MAP) changes. After, the rats were anesthetized for brain perfusion and processed for tyrosine hydroxylase (TH) and the transcription factor Phox2b immunoreactive. PE produced a similar increased in MAP in 6‐OHDA and control groups. However, the bradycardia was blunted in 6‐OHDA (D = ‐7.5±0.5 to ‐62±6 vs. vehicle: ‐29.5±1.2 to ‐148.5±9.8 bpm). In 6‐OHDA, the SNP produced a smaller decrease in MAP (Δ = ‐18±2.6 to ‐24.5±0.8 vs. vehicle: ‐60.3±2 to ‐96.5±1.9 mmHg) and a smaller increase in HR (Δ = 34.75±3.4 to 59.5±7.8 vs. vehicle: 61±7.8 to 101.3±6 bpm). Ocurred a reduction in TH neurons in the substantia nigra (85%), in the C1 regions (70%) and in the Phox2b + neurons in the NTS (48%). We observed an impairment of baroreflex sensitivity in the 6‐OHDA model of PD, which could be correlated with a reduction in the neuronal cytoarchitecture of brainstem regions involved in cardiovascular control Financial support: FAPESP, CNPq, CAPES/PROEX