HIGH CORTICOSTERONE/DHEA-s RATIO IN TRYPANOSOMA CRUZI INFECTION IN YOUNG RATS IS ASSOCIATED WITH INCREASED SUSCEPTIBILITY

PÉREZ AR, BERTOYA AA, REVELLI S, GARCÍA F.

MEMóRIAS DO INSTITUTO OSWALDO CRUZ.

FUNDACO OSWALDO CRUZ

Lugar: Rio de Janeiro; Año: 2011 vol. 106 p. 416 - 423

0074-0276

It is well known that acute phase of Chagas´ disease is more severe in children than in adults. We have previously established that prepubertal (PP) male rats infected with T. cruzi are more susceptible compared with adult (A) counterparts. In the context of immunoendocrine interactions, simultaneous assessment of hormone levels and cytokines released throughout acute infection period may offer a better comprehension of disease pathology and its relationship with age.PP and A rats were infected with 1.106 or 7.106 parasites respectively. Blood was collected at 0, 7, 14, 21 and 28 days post-infection for determination of gonadal and adrenal hormones, TNF-alfa and IL-10, and specific IgM and IgG subtypes.PP animals showed higher parasitemias and an inflammatory environment with increased TNF-alfa production. In parallel, they showed a raise in corticosterone as well as in corticosterone /DHEA-sulfate ratio, in line with a more susceptible state. In contrast, A male rats were capable to restrict the parasite burden by a better IgG antibody synthesis, likely favored by enhanced estradiol levels, both positively correlated at day 7 post- infection (n=8; rs=0.809; p<0.05). Present results suggest that the increased vulnerability to parasite infection in young animals is associated with an unsuitable immunoendocrine milieu compared with adult rats.