RESUMO. A doença de Alzheimer (DA) e o transtorno depressivo maior (TDM) são transtornos que acometem idosos e estão associadas ao estresse crônico e à desregulação do eixo hipotálamo-hipófise-adrenal (HPA), que repercute em alterações nos níveis de cortisol (basal e reatividade). Objetivo: Investigar a reatividade do cortisol em uma única sessão de exercício físico em pacientes com TDM e com DA e compará-la com a de idosos saudáveis. Métodos: Indivíduos controle saudáveis (n=10) e idosos com diagnóstico clínico de TDM (n=08) e DA (n=13) foram submetidos a uma única sessão de exercício aeróbio em esteira rolante, durante 30 minutos, em intensidade moderada. O cortisol salivar foi coletado antes e depois do estressor agudo. Na estatística, foram realizadas as análises de variância (ANOVA) de medidas repetidas, correlação de spearman e regressão linear. Resultados: Não foi encontrada interação para momento x grupo [F (2.000, 28.000)=1.285; p=0,293] e tampouco efeito para o grupo (F=0,323; p=0,727). Todavia, foi observado efeito significativo para o momento [F(1,000, 28,000)=4,930; p=0,035], mostrando diminuição dos níveis de cortisol no pós-exercício para todos os grupos. O tamanho do efeito (TE) foi considerado pequeno para o grupo TDM (d=0,402) e trivial para o DA (d=0,166) e o saudável (d=0,090). Conclusões: Todos os participantes apresentaram diminuição da reatividade do cortisol a um estressor físico, o que pode estar associado a um comprometimento no enfrentamento de um estressor agudo.

ABSTRACT. Some prevalent mental disorders in the elderly, such as Alzheimer's disease (AD) and major depression disorder (MDD), are associated with chronic stress and consequently with possible dysregulation of hypothalamic–pituitary–adrenal (HPA) axis and cortisol levels in basal conditions or in the reactivity of an acute stressor. However, evidence of cortisol behavior after a physical stressor in patients with AD and MDD is scarce. Objective: This study aimed to investigate the cortisol reactivity to a single session of physical exercise in patients with MDD and AD and compare it to healthy control (HC) older individuals. Methods: HC individuals (n=10) and elderly with clinical diagnostic of MDD (n=08) and AD (n=13) were submitted to a single bout of aerobic exercise in a treadmill during 30 minutes of moderate intensity. Salivary cortisol was collected before and after acute stressor. A repeated-measure analysis of variance (ANOVA), spearman correlation, and linear regression were performed. Results: The repeated-measure ANOVA revealed no interaction for cortisol on the moment×group [F(2.000, 28.000)=1.285; p=0.293] and no effect for group (F=0.323; p=0.727). However, a significant effect for moment [F(1.000, 28.000)=4.930; p=0.035] was found, with a decreased cortisol levels in postexercise for all groups. The effect size (ES) of cortisol reduction was small for patients with MDD (d=0.402) and trivial for patients with AD (d=0.166) and HC group (d=0.090). Conclusions: All participants show a decreased cortisol reactivity to a physical stressor, which can be associated with an impairment in coping with an acute stressor.

Although physical inactivity figures as one of the main causes attributed to mortality, the damage caused by excessive exercise is also a reality. Professional athletes, amateur or uncompetitive modalities beneficiaries are often affected by deleterious conditions resulting from excessive exercise, such as neurological, endocrine and immune origin. The thin line between losses and benefits of successive fatiguing sessions effort depends on the understanding of concepts and methodological training principles. Exercise may have a paradoxical relationship and its consistent prescription in terms of public health depends on a better understanding of their cellular mechanisms. In this sense, the purpose of this review was to explore a promising topic in sports science, able to contribute to elucidate such mechanisms: Th1 and Th2 profile of the immune response related with chronic exhausting exercise and overtraining.

INTRODUÇÃO: Durante o último século, o homem tornou-se menos ativo fisicamente, adotando hábitos cada vez mais sedentários. Isto promoveu aumento na incidência de doenças crônicas tais como doenças cardiovasculares, diabetes do tipo 2 e síndrome metabólica. A prática de atividade física pode influenciar o estado de higidez alterando estados metabólicos e também o sistema imunológico. OBJETIVO: Revisar na literatura estudos que abordem os efeitos promovidos pelo exercício físico no desenvolvimento da resposta imunológica e suas possíveis vias de transdução de sinais. MÉTODOS: Foram consultadas as bases de dados SciELO e PubMed. RESULTADOS: A literatura disponível mostra que durante a prática de exercício, várias subpopulações de leucócitos são alteradas de acordo com a intensidade e duração da atividade desempenhada. Exercícios de intensidade moderada estimulam uma resposta pró-inflamatória, enquanto aqueles de alta intensidade tendem a promover respostas anti-inflamatórias visando diminuir os danos na musculatura esquelética. Tais alterações são vistas em células apresentadoras de antígeno (como macrófagos e células dendríticas), neutrófilos, células natural killers (NK) e em moléculas de superfície como os receptores do tipo Toll (TLR) e do complexo principal de histocompatibilidade de classe II (MHC II), além das modificações promovidas em todo o repertório de citocinas. CONCLUSÃO: O estado atual do conhecimento permite considerar que as alterações no sistema imune são dependentes dos parâmetros inerentes ao exercício e que para que todas estas alterações ocorram, algumas cascatas de sinalização celular são acionadas, dando origem a um complexo processo de fosforilação/desfosforilação que culmina em ativação de fatores de transcrição, tradução de RNAm, síntese proteica e proliferação celular.

INTRODUCTION: Over the last century, people have become less active, adopting more sedentary habits. This scenario has increased the incidence of chronic diseases such as cardiovascular diseases, type 2 diabetes and metabolic syndrome. The practice of physical activities can influence healthiness by altering the metabolic state and also the immune system. OBJECTIVE: To review the literature for studies that address the effects promoted by physical exercise on the development of immune responses and the possible signal transduction pathways. METHODS: The SciELO and PubMed data bases were consulted. RESULTS: The available literature shows that during the practice of exercise, various subpopulations of leukocytes are altered in accordance with the intensity and duration of the activity performed. Exercise of moderate intensity stimulates a pro-inflammatory response, while those of high intensity tend to promote anti-inflammatory responses with the purpose to decrease damage to skeletal muscle. Such alterations are observed in cells that present antigens (such as macrophages and dendritic cells), neutrophils, natural killer cells (NK) and in surface molecules like Toll-like receptors (TLR) and major histocompatibility complex class II, as well as the entire repertoire of cytokines. CONCLUSION: The current state of knowledge suggests that the alterations in the immune system are dependent on parameters inherent to exercise and that in order to have all these alterations occurring, some cell signaling cascades are activated, giving rise to a complex process of phosphorylation/dephosphorylation that culminates in the activation of transcription factors, translation of mRNA's, protein synthesis and cell proliferation.

The substitution of equine chorionic gonadotropin (eCG) by follicle-stimulating hormone (FSH) in protocols for synchronization of ovulation in Santa Inês ewes was assessed. Ten females were submitted to the insertion of intravaginal sponges containing 60 mg medroxyprogesterone acetate for 10 days; after this period sponges were withdrawn and the animals were randomly divided into two groups. Group 1 (n = 5): intramuscular injection of 0.5 mL d-cloprostenol and 300 UI eCG; Group 2 (n = 5): intramuscular injection of 0.5 mL d-cloprostenol and 20 mg FSH. Interval between sponge withdrawal and estrus beginning was 27.7 h and 35.9 h for eCG and FSH, respectively. Interval between sponge withdrawal and the end of estrus was 55.8 h for eCG treatment and 55.6 h for FSH treatment. Estrus length was 29.3 h and 19.6 h, for eCG and FSH treatments, respectively. The biggest follicle and the second in size measured 0.74 cm and 0.54 cm for eCG treatment, whereas for the FSH treatment they measured 0.73 and 0.50 cm. The interval between the beginning of estrus and ovulation was similar within all groups: 21.0 h for eCG treated ewes and 25.2 h for the ones treated with FSH. Ewes treated with eCG presented an interval of 47.5 h between sponge withdrawal and ovulation, while the ones treated with FSH presented a 61.1 h interval. Ovulation occurred 8.3 h before the end of estrus in the eCG group. On the other hand, ewes treated with FSH ovulated 5.5 h after the end of estrus. Estrus and ovulation were efficiently synchronized in Santa Inês ewes by using long-term progestogen protocol associated to the administration of 20 mg FSH, along with Prostaglandin F2α (PGF2α) at the moment of sponge withdrawal, thus substituting the use of eCG.