The Molecular Mechanism of Exercise for Treatment of Patients with Major Depression: A Preliminary Report on the Dynamics of Metabolites of Nitric Oxide and Catecholamines.

BACKGROUND: There has been increasing evidence that exercise therapy is effective in the treatment and prevention of major depression (MD). However, the basic molecular mechanisms underlying the effects of exercise on MD remain unclear. We conducted a preliminary study to clarify the effect of exercise therapy on MD, focusing on the dynamics of nitric oxide (NO) and catecholamine metabolites, which have been found to be associated with MD. METHODS: Eleven outpatients with mild to moderate MD and 37 healthy controls (HC) were included in the study. The participants' clinical records and questionnaires were screened for their past medical history. For their exercise therapy, the participants were instructed to walk the equivalent of 17.5 kcal/kg/week for 8 weeks. Blood samples were collected from all participants at baseline, 4 weeks, and 8 weeks after the start of exercise therapy, and plasma metabolites of NO (NOx), homovanillic acid (HVA), and 3-methoxy-4-hydroxyphenylglycol (MHPG) were analyzed. We also assessed the 17-item Hamilton Rating Scale for Depression (HRSD-17) in patients with MD. A mixed-effects regression model was used to compare the mean values by time (baseline, 4, and 8 weeks) for the three corresponding groups (NOx, MHPG, and HVA). RESULTS: HRSD-17 scores decreased significantly in the MD group after 8 weeks of exercise therapy. NOx and MHPG increased, but there was no significant change in HVA in the MD group after the exercise therapy. NOx decreased after exercise, and HVA increased significantly from baseline after 4 weeks of exercise but decreased after 8 weeks of exercise in the HC group. CONCLUSIONS: The effects of exercise on NOx, MHPG, and HVA may differ between MD and HC. The potential mechanisms for the benefits of walking exercise in MD patients will be the subject for future research.

Pretreatment plasma HVA and haloperidol response in acute mania.

INTRODUCTION: Pretreatment plasma homovanillic acid (HVA) levels have been reported to be a correlate of clinical response to typical antipsychotics for schizophrenic, bipolar manic, and mixed groups of psychotic patients. Biological markers of clinical response to antipsychotics could be useful for optimizing drug treatment. METHOD: Thirty-one consenting acute inpatient subjects between ages 19 and 66 years with a DSM-III-R clinical diagnosis of bipolar disorder, manic with psychotic features were entered into this double-blind study and were randomly assigned to receive either haloperidol 25 mg/day or haloperidol 5 mg for the 3-week study. Subjects also received one of the following concomitant medications: standard lithium, lorazepam 4 mg/day, or placebo. RESULTS: The primary multiple regression analysis, including all subjects on both haloperidol doses, yielded a significant main effect for pretreatment plasma HVA (n=31, F=5.7, P=0.025), indicating that higher pretreatment plasma HVA was predictive of better clinical response. In addition, the interaction between haloperidol dose and pretreatment plasma HVA was also significantly associated with clinical response (F=12.59, P=0.0015). When the two haloperidol doses were analyzed separately, we found that pretreatment plasma HVA was only correlated with clinical response in the low haloperidol 5 mg/day group (n=18, F=11.73, P=0.0038) and was unrelated to clinical response to the high haloperidol 25 mg/day group. LIMITATIONS: The sample size was small. Results may have been confounded by prior antipsychotic treatment and concomitant use of lithium or lorazepam. DISCUSSION: These results suggest that pretreatment plasma HVA could be useful for dosing antipsychotics. Patients with high plasma HVA levels would be good candidates for low-dose treatment because they are more likely to improve on such a dose, while patients with low plasma HVA levels might warrant more rapid dosage escalation.

[Salsolinol, 3-O-methyl-dopa and homovanillic acid in the cerebrospinal fluid of Parkinson patients]. / Salsolinol oraz 3-0-metyldopa i kwas homowanilinowy w plynie mózgowo-rdzeniowym u osób z choroba parkinsona.

Salsolinol is one of the dopamine-derived tetrahydroisoquinolines, supposed to be a potent dopaminergic neurotoxin, similar to MPTP. Its systemic administration induced parkinsonism in monkeys. The aim of the study was to compare the concentration of salsolinol and the metabolite of L-dopa, 3-O-MD, and the metabolite of dopamine, HVA, in the cerebrospinal fluid of patients with different degrees of parkinsonism, treated or nontreated with l-dopa. Lumbar CSF was obtained from 26 patients with Parkinson's disease (15 early and 11 advanced parkinsonism) and from six healthy controls. The presence of salsolinol, HVA and 3-O-MD was assayed with a sensitive HPLC method employing C18 (Hypersil BDS) column. The analysis of the results demonstrated that the concentration of salsolinol was related to the degree of parkinsonism but not affected by l-dopa treatment. In contrast, HVA and 3-O-MD were significantly elevated in patients receiving l-dopa but did not correlate with the severity of parkinsonism. The results suggest that salsolinol in the cerebrospinal fluid does not originate from exogenous l-dopa and its elevation in cerebrospinal fluid may be an indicator of the advancement of parkinsonism.

Venezuelan equine encephalomyelitis virus infection: effect on dopamine metabolism of communication / Infección con el virus de la encéfalomielitis equina venezolana: efecto sobre el metabolismo de la dopamina en el cerebro del ratón: comunicación preliminar

Inoculation of VEE virus to mice produces an increase in brain dopamine and homovanillic acid. This rise possibly results from an increase on the levels of L-Tyrosine hydroxylase