RESUMEN
ABSTRACT Objective: We hypothesized that perinatal manipulations of the nitrergic system would affect adult animal behaviors. Methods: We tested this hypothesis by perinatally administering N(G)-Nitro-L-arginine methyl ester (L-NAME), a non-specific antagonist of nitric oxide synthase for 15 days and assessed anxiety- and depression-like behaviors in adult mice. At 70 days of age, the mice were subjected to a battery of tests consisting of the open-field, light/dark box, forced swim, and tail-flick tests. The tests were performed at two-day intervals, and the order of the tests within the battery was determined according to the progressive invasiveness degree. Results: L-NAME-treated animals exhibited decreased anxiety-like behavior in the light/dark box and open field tests, with no change in locomotor activity. Additionally, they demonstrated decreased depression-like behavior in the forced swim test and no change in pain perception in the tail-flick test. Conclusion: The nitrergic system is possibly involved in neural circuitry development that regulates behaviors since blocking perinatal nitric oxide production decreases anxiety- and depression-like behaviors in adult mice.
RESUMEN
Abstract Warm-up is broadly used to increase performance and protect against injury in sports. However, the effects of different models of warm-up on maximal exercise and the subsequent recovery period are undetermined. This study aimed to assess the effects of different warm-ups on performance, blood pressure and autonomic control. Methods: 53 subjects rested for 5 minutes and then were randomly allocated to one of four experimental groups: Control (CTR), Aerobic Warm-up (AER), Static (SST) or Ballistic (BST) stretch. Immediately after warm-up, they performed a maximal cycling test and rested for 30 minutes. Heart rate variability (HRV), Systolic (SBP) and diastolic (DBP) blood pressure were assessed throughout the entire experiment. Statistical analysis was performed by one-way ANOVA with Tukey post-test or two-way ANOVA followed by either Bonferroni or Dunnet post-test, when appropriate. Warm-up did not change test performance or HRV (p>.05), however, when compared between-groups, SBP was higher in BST against all groups (p<.05) after warm-up, and lower in SST and AER after maximal test (p>.05). When compared to baseline values SST showed increased SBP in recovery (p<.05) while only AER and BST showed post-exercise hypotension at 30 minutes (p<.05). In conclusion, despite the lack of effects on performance, AER and BST seem to improve while SST seems to impair the recovery of cardiovascular parameters in an autonomic-independent mechanism.
Resumo Aquecimento é comumente utilizado para aumentar o desempenho e proteger contra lesões no esporte. No entanto, os efeitos de diferentes modalidades de aquecimento sobre o exercício máximo e subsequente período de recuperação não foram determinados. Este estudo objetivou avaliar o efeito de diferentes aquecimentos sobre o desempenho, pressão arterial e controle autonomico. 53 sujeitos descansavam por 5 minutos em seguida eram aleatoriamente alocados em um dos quatro grupos experimentais. Controle (CTR), Aquecimento aeróbio (AER) e alongamentos estático (SST) ou balístico (BST). Imediatamente após o aquecimento eles efetuavam um teste máximo em bicicleta e descansavam por 30 minutos. A variabilidade da frequência cardíaca (HRV), pressão arterial sistólica (SBP) e diastólica (DBP) foram medidas durante todo o experimento. Analise estatística foi feita pelo two-way ANOVA e pós-teste de Bonferroni ou Dunnet quando apropriado. O Aquecimento não alterou a performance ou HRV (p>,05), todavia, quando comparadas entre grupos, SBP aumenta em BST contra todos os grupos após o aquecimento (p<,05) e diminui em SST e AER após teste máximo (p<,05).Quando comparadas aos valores basais SST aumenta SBP na recuperação, enquanto apenas AER e BST mostram hipotensão pós-exercício em 30 minutos (p<,05). Conclui-se que, apesar da falta de efeitos sobre o desempenho, AER e BST parecem melhorar, enquanto SST piora a recuperação de parâmetros cardiovasculares, através de um mecanismo autonômico-independente.