ABSTRACT
INTRODUCTION: Alzheimer disease (AD) is the most common form of dementia in the elderly that slowly destroys memory and cognitive functions. The disease has no cure and leads to significant structural and functional brain abnormalities. To facilitate the treatment of this disease, we aimed to investigate proline-rich peptide (PRP-1) action of hypothalamus on hippocampal (HP) neurons and dynamics of their recovery, after intracerebroventricular (ICV) injection of amyloid-ß (Aß). METHODS: Experiments were carried out on 24 adult, male Albino rats (average weight: 230±30 g). The animals were randomly divided into 3 groups (control, Aß, and Aß plus PRP-1). Electrophysiological patterns of hippocampal neurons in response to stimulation of entorhinal cortex (EC) with high frequency stimulation (50 Hz) were studied. RESULTS: It was found that Aß (25-35) suppresses the electrical activity of hippocampal neurons. The PRP-1 would return this activity to normal levels. CONCLUSION: In general, PRP-1 has protective effect against AD-related alterations induced by amyloid peptides. This protective effect is probably due to stimulation of the immune and glia system.
ABSTRACT
OBJETIVO: Examinar o efeito de 12 semanas de (3 dias/sem) de treinamento concorrente e 4 semanas de destreinamento nas concentrações séricas de adiponectina e níveis de condicionamento físico em meninos obesos sem intervenção dietética. MÉTODOS: vinte e quatro meninos saudáveis, 11-13 anos de idade com índice de massa corporal > 28 participaram voluntariamente do estudo. Estes foram divididos em dois grupos, experimental (n= 12) e controle (n=12). RESULTADOS: Concentrações de adiponectina após 12 semanas tiveram declínio significativo em ambos os grupos em comparação com o nível basal (p < 0,05). VO2 pico, flexibilidade, força, endurance de abdominais e agilidade aumentaram significativamente no grupo experimental comparado com o grupo controle (p < 0.05). Foi evidenciado que após destreinamento de 4 semanas, a adiponectina sérica não se alterou significativamente no grupo experimental e que condicionamento físico benéfico foi gradualmente diminuído. CONCLUSÃO: Nossos resultados sugerem que os efeitos benéficos do exercício físico no condicionamento são temporários. Uma vez que o processo de adaptação é reversível, parece que as concentrações de adiponectina foram inevitavelmente afetadas pelas alterações morfológicas e hormonais que ocorreram durante a puberdade em meninos.
OBJECTIVE: To examine the effect of 12 weeks of (3 days/week) concurrent training and 4 weeks of detraining on serum adiponectin concentrations and physical fitness levels in obese boys without dietary intervention. METHODS: 24 healthy boys, 11-13 years old with body mass index >28 voluntarily participated in the study. They were divided into two groups, experimental (n = 12) and control (n = 12). RESULTS: Adiponectin concentrations after 12 weeks presented significant decline in both experimental and control group compared with the baseline (p < 0.05). VO2 peak, flexibility, strength, endurance of sit-ups and agility significantly increased in the experimental group compared with the control group (p < 0.05). It was shown that after a 4-week detraining, serum adiponectin did not significantly change in the experimental group and that beneficial physical fitness was gradually decreased. CONCLUSION: Our results suggest that the beneficial effects of exercise training on physical fitness are temporary. Since the process of adaptation is reversible, it seems that adiponectin concentrations were inevitably affected by morphological and hormonal changes that occurred during puberty in boys.
ABSTRACT
We tested the action of proline-rich peptide (PRP-1) and cobra venom Naja Naja Oxiana (NOX) on Deiters' nucleus neurons at 3rd, 15th and 35th days after unilateral labyrinthectomy (UL). Early and late tetanic, post-tetanic potentiation and depression of Deiters'neurons to bilateral high frequency stimulation of hypothalamic supraoptic and paraventricualar nuclei was studied. The analysis of spike activity was carried out by mean of on-line selection and special program. The complex averaged peri-event time and frequency histograms shows the increase of inhibitory and excitatory reactions of Deiters' neurons at early stage of vestibular compensation following PRP-1 and NOX injection, reaching the norm at the end of tests. In histochemical study the changes in Ca(2+)-dependent acidic phosphatase (AP) activity in neurons was discovered. It was shown that in UL animals the total disappearance or delay of decolorizing of Deiters' neurons lead to neurodegenerative pattern as cellular "shade". AP activity after UL and PRP-1 injection exerts more effective recovery of neurons in comparison with events, observed after the administration of NOX. The data of this study indicate that PRP-1 and NOX are protectors, which may successfully recover the disturbed vestibular functions.