Administração repetida de baixas doses de reserpina: um possível modelo para o estudo de déficits cognitivos e motores associados à Doença de Parkinson

Parkinson's disease (PD) is one of the most common neurodegenerative brain disorders and is characterized primarily by a progressive degeneration of dopaminergic neurons nigroestriatais. The main symptoms of this disease are motor alterations (bradykinesia, rigidity, tremor at rest), which can be highly disabling in advanced stages of the condition. However, there are symptomatic manifestations other than motor impairment, such as changes in cognition, mood and sensory systems. Animal models that attempt to mimic clinical features of PD have been used to understand the behavioral and neural mechanisms underlying neurophysiological disturbance of this disease. However, most models promote an intense and immediate motor impairment, consistent with advanced stages of the disease, invalidating these studies for the evaluation of its progressive nature. The administration of reserpine (a monoamine depletor) in rodents has been considered an animal model for studying PD. Recently we found that reserpine (in doses lower than those usually employed to produce the motor symptoms) promotes a memory deficit in an aversive discrimination task, without changing the motor activity. It was suggested that the administration of this drug in low doses can be useful for the study of memory deficits found in PD. Corroborating this data, in another study, acute subcutaneous administration of reserpine, while preserving motor function, led to changes in emotional context-related (but not neutral) memory tasks. The goal of this research was to study the cognitive and motor deficits in rats repeatedly treated with low doses of reserpine, as a possible model that simulates the progressive nature of the PD. For this purpose, 5-month-old male Wistar rats were submitted to a repeated treatment with vehicle or different doses of reserpine on alternate days. Cognitive and motor parameters and possible changes in neuronal function were evaluated during treatment. The main findings were: repeated administration of 0.1 mg / kg of reserpine in rats is able to induce the gradual appearance of motor signs compatible with progressive features found in patients with PD; an increase in striatal levels of oxidative stress and changes in the concentrations of glutamate in the striatum were observed five days after the end of treatment; in animals repeatedly-treated with 0. 1 mg/kg, cognitive deficits were observed only after the onset of motor symptoms, but not prior to the onset of these symptoms; 0.2 mg / kg reserpine repeated treatment has jeopardized the cognitive assessment due to the presence of severe motor deficits. Thus, we suggest that the protocol of treatment with reserpine used in this work is a viable alternative for studies of the progressive appearance of parkinsonian signs in rats, especially concerning motor symptoms. As for the cognitive symptoms, we suggest that more studies are needed, possibly using other behavioral models, and / or changing the treatment regimen

Avaliação da estimulação da medula espinhal como modelo de tratamento da doença de parkinson no primata Callithrix jacchus

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior

Avaliação dos efeitos do extrato de Passiflora cincinnata Masters em camundongos: efeito na ansiedade e potencial neuroprotetor

Anxiety disorders and Parkinson’s disease (PD) affect a large portion of the world population. Indeed, therapeutic alternatives available do not contribute to improve most clinical conditions and/or are linked with undesirable side effects. Thus, there is a great demand for the development of new drugs to treatment of these diseases. Passiflora cincinnata Mast. is a native species present in several Brazilian states, popularly known as “maracujá do mato”, “maracujá tubarão” or “maracujá mochila”. Additionally, species of Passiflora genus are traditionally known for their exotic flowers, edible fruits with pronounced flavor and for their sedative, tranquilizer and anxiolytic properties reported by folk medicine. These plants possess important organic compounds such as phenols, cyanogenic glycosides, flavonoids and alkaloids, which are responsible for the anxiolytic, antioxidant, anti-inflammatory, antihyperglycemic, among others activities when tested in mammals. Despite this fact, only a few studies have been conducted to investigate the possible in vivo biological effects of Passiflora cincinnata Mast extracts. Thereby, in this study we evaluated the effects of the alcoholic extract of this plant in anxiety and PD animal model. Mice acutely or chronically administered with ethanolic extract of P. cincinnata do not showed any anxiogenic- or anxyolitic-like effect in elevated plus maze (EPM). In order to reproduce PD symptom’s in mice, we administered repeated injections of reserpine which progressively induced motor impairments such as increase in catalepsy, oral movements, and reduction of the average speed of the animals in the open field, as well as depleted dopamine prodution in SNpc cells. Furthermore, this treatment resulted in the loss of aversive memory recall in mice when undergoing PMDAT. Yet, passiflora group also show this amnesic profile. However, animals treated concomitantly with the alcoholic extract of Passiflora cincinnata Mast. showed higher latency for the onset of motor impairment evaluated by catalepsy. Thus, our results shows that the alcoholic extract of the plant P. cincinnata was able to delay the onset of the catalepsy induced by reserpine administration, plus reverted the depletion of dopamine production in SNpc cells.

Estudo comparativo entre antipsicóticos atípicos no tratamento da esquizofrenia e sua influência na qualidade de vida dos pacientes

Schizophrenia is a severe and persistent mental illness; diagnosis occurs mainly during adolescence. The pharmacological treatment is done with typical and atypical antipsychotics. Atypical have the advantage of reduced extrapyramidal effects, which make them promising for the treatment of schizophrenia, furthermore, they have shown significant metabolic and hormonal changes. The objective of this study was to evaluate the influence of atypical antipsychotics, olanzapine and risperidone on the quality of life and on their adverse effects in schizophrenic patients. For this we analyzed the quality of life of patients with implementation of EuroQol-5D-3L instrument and performing biochemical and hormonal tests, blood pressure measurement, and measurement of anthropometric indices, besides the application of Ugvalg scales for Kliniske Undersgelser (UKU) and Simpson-Angus, who evaluated the side effects caused by drugs. Data were analyzed using the Student t test and chi-square test, with 5% significance level. The results showed that the EuroQol the antipsychotic olanzapine causes significant losses associated with personal care (p <0.001). Comparing the two groups of antipsychotics, the average years of quality-adjusted life, known per QALY was favorable for the risperidone group (p <0.032). The results of olanzapine and risperidone groups were compared. In terms of socioeconomic, it was observed that men used, the prevalent form, olanzapine (p <0.008); this same group showed the following results significantly unfavorable, related to anthropometric variables: waist circumference (p <0.01), hip circumference (p <0.02), weight (p <0.02) and blood pressure (p <0.04). The biochemical and hormonal analyzes showed that olanzapine resulted in losses related to the following variables: triglycerides (p <0.04), HDL cholesterol in men (p < 0.02) and cortisol (p < 0.01). In risperidone users, the only negative value was prolactin (p < 0.04). Regarding the analysis of the Simpson-Angus scale, the group treated with olanzapine was handicapped because the average total scores for olanzapine was 0.38, while for risperidone was 0.11 (p < 0.02). In the UKU scale, the following results were obtained also unfavorable for the olanzapine group: fatigue (P <0.02), dystonia (p <0.01) and tremor (p <0.03). According to the UKU scale, the side effects present in the risperidone group included: gynecomastia (p <0.01), ejaculatory dysfunction (p <0.02) and erectile dysfunction (p <0.02). It was concluded that olanzapine users had the worst score of quality of life, higher metabolic risks associated with overweight and inadequate lipid profile and greater tendency to extrapyramidal manifestations. However, risperidone users were more likely to adverse reactions due to hormonal changes.