ABSTRACT
We examined the correlations between cerebrospinal fluid (CSF) concentrations of homovanillic acid (HVA) and 5-hydroxyindole acetic acid (5-HIAA) and imaging assessment scores, using 123I-Ioflupane SPECT and 123I-MIBG myocardial scintigraphy in 23 drug naïve PD patients. The CSF 5-HIAA concentration correlated with the H/M ratio of the delayed image (r = 0.458, p < 0.05) and the washout rate (r = - 0.642, p < 0.01) of 123I-MIBG myocardial scintigraphy. These correlations suggest some unclarified pathophysiological links between the central serotonergic and cardiac sympathetic systems.
Subject(s)
3-Iodobenzylguanidine/pharmacokinetics , Hydroxyindoleacetic Acid/cerebrospinal fluid , Iodine Radioisotopes/pharmacokinetics , Myocardial Perfusion Imaging , Myocardium/metabolism , Nortropanes/pharmacokinetics , Parkinson Disease/metabolism , Radiopharmaceuticals/pharmacokinetics , Tomography, Emission-Computed, Single-Photon , Aged , Aged, 80 and over , Autonomic Fibers, Postganglionic/metabolism , Biomarkers , Cognitive Dysfunction/etiology , Dementia/etiology , Female , Heart Conduction System/physiopathology , Homovanillic Acid/cerebrospinal fluid , Humans , Male , Middle Aged , Organ Specificity , Parkinson Disease/cerebrospinal fluid , Parkinson Disease/psychology , Serotonin/metabolismABSTRACT
OBJECTIVE: Various stressors induce stress responses through the hypothalamic-pituitary-adrenal and the sympathetic-adrenal-medullary axes, which are regulated, in part, by orexin. For example, secretion of orexin in the hypothalamus is increased in rats exposed to the stress of social isolation for 1 week. In this study, the antistress effects of Kampo medicine Yokukansan (YKS) via the regulation of orexin secretion were investigated using a rat model. METHODS AND RESULTS: The administration of 300 mg/kg per day of YKS to rats for 1 week significantly decreased the plasma orexin levels compared with non-treated rats, whereas the administration of 1,000 mg/kg of YKS had no effect on orexin levels. Therefore, 300 mg/kg of YKS was an effective dose for controlling orexin secretion. Subsequently, rats were divided into group-housed control (Con), individually housed stress (Stress), and individually housed YKS (300 mg/kg)-treated stress (Stress + YKS) groups. After 1 week, a resident-intruder aggression test was performed, and the plasma levels of orexin and corticosterone were measured. In the Stress group, aggressive behavior and the levels of corticosterone and orexin significantly increased compared with the Con group; however, these effects were inhibited in the Stress + YKS group. Further, an orexin receptor antagonist (TCS 1102; 10 mg/kg) was intraperitoneally administered to rats exposed to isolation stress to determine whether orexin was involved in stress responses. Under these conditions, aggressive behavior and the level of corticosterone significantly decreased compared with the Stress group. CONCLUSION: These results suggest that orexin is involved in the control of stress response and that YKS exerts an antistress effect via the regulation of orexin secretion.
ABSTRACT
Correlation between frontal-executive function and motor functions, such as gait and postural control, has attracted attention in Parkinson's disease (PD). However, correlations between other cognitive functional domains and motor functions have not been examined. Thus, we examined the correlation between different domains of cognitive function and motor functions. Sixty-five PD patients were recruited for the present study. Cognitive functions were assessed by the 10 subtests of the Neurobehavioral Cognitive Status Examination (COGNISTAT). Motor functions were assessed by the Unified Parkinson's Disease Rating Scale (UPDRS) as partIII for general motor function and sum of related items for tremor, rigidity, bradykinesia, and postural instability. Spearman's correlation coefficients between each cognitive and motor assessment were compared. Among the 10 subtests of the COGNISTAT, constructions showed significant correlation with UPDRS partIII (p<0.01), bradykinesia (p<0.01), and postural instability (p<0.001). The latter correlation was stronger than those between all motor assessments and both all patients backgrounds and other COGNISTAT subtests. In PD patients, postural instability correlates with not only frontal executive dysfunctions but also parietal dysfunctions, such as visuospatial and constructive impairments. The postural maintenance system is suggested to share common physiology with not only frontal-executive function but also parietal functions.
