Seasonal dependency of the effects of experimental stressors on @entity5 XXXX in @entity19 @entity2 .

@entity5 @entity19 @entity2 @entity2493 @entity3
Increasing evidence indicates that the application of stressor paradigms in experimental animals affects @entity5 incidence and progression. However, a high heterogeneity appears both for the animal- @entity5 system used and for the characteristics of the stressor employed. A high variability was observed also with the application of rotational stress, a carefully and widely characterized mild psychological stressor, to @entity19 @entity2 . The aim of this work has been therefore to examine the possible seasonal dependency of the effects of experimental stressors (rotational stress, forced immobilization and electric foot shock) on spontaneous lung @entity3 formation in @entity19 @entity2 . The possible participation of pineal gland and of @entity2493 have also been examined including in the experimental protocol the measurement of @entity2493 urinary excretion. The stressor paradigms used significantly increased @entity3 weight in spring, in comparison with non-stressed animals. When examined in winter, rotational stress and foot shock significantly decreased @entity3 formation, in comparison with non-stressed @entity19 . The effects of forced immobilization were not season-dependent. The @entity2493 urinary excretion has been measured in relation to the seasonal effects of rotational stress. Nocturnal @entity2493 excretion is markedly increased by rotational stress in spring and is remarkably decreased in winter. These variations in endogenous @entity2493 levels caused by rotational stress appear to directly correlate with the effects of the stressor or @entity3 . These results lend support to the view that the mechanisms underlying the @entity5 enhancing action of stressors involve the psychoneuroendocrine network, and indicate the relevance of chronobiology in experimental @entity5 research and neuro-immuno-modulation.
