RESUMO
The incidence and progression of disorders associated with an unbalanced immune response has among many factors the gender as a contributory factor. The aims of this work were to evaluate the effects of orchiectomy and the immune response during the experimental Trypanosoma cruzi infection. Young adult, male Calomys callous were i.p. inoculated with 1 x 10(5) blood trypomastigotes of the CM strain of T. cruzi and divided in groups: Control, Sham and Castrated. Castrated group displayed significantly lower values for prostate and seminal vesicle weights indicating a drastic drop of testosterone plasmatic levels. Orchiectomized animals also displayed lesser number of blood parasites, enhanced lytic antibody percentage, splenocyte proliferation and NO concentration when compared to its sham and control counterparts, indicating that steroid gonadal ablation actually influences immune response triggering a more efficient cellular and humoral response which led animals to become more resistant against T. cruzi infection.
Assuntos
Doença de Chagas/metabolismo , Testosterona/fisiologia , Trypanosoma cruzi/crescimento & desenvolvimento , Trypanosoma cruzi/imunologia , Animais , Anticorpos Antiprotozoários/biossíntese , Proliferação de Células , Doença de Chagas/imunologia , Doença de Chagas/parasitologia , Modelos Animais de Doenças , Ativação Linfocitária , Macrófagos Peritoneais/metabolismo , Masculino , Óxido Nítrico/análise , Orquiectomia , Tamanho do Órgão , Parasitemia/parasitologia , Próstata/patologia , Glândulas Seminais/patologia , Sigmodontinae , Baço/citologia , Baço/imunologiaRESUMO
Calomys callosus is a wild rodent found naturally infected with different Trypanosoma cruzi strains. In the work described here, groups of male and female C. callosus were subjected to orchiectomy, ovariectomy and sham operation. One month after surgery, animals were inoculated intraperitoneally (i.p.) with 4x10(4) blood trypomastigotes of the "Y" strain of T. cruzi. Parasitemia, triglycerides, nitric oxide (NO) and concanavalin A (ConA)-induced proliferation were evaluated. Parasitemia during the course of infection was significantly higher in infected and sham operated animals as compared to infected orchiectomized animals. The opposite was observed in the ovariectomized and infected group. Orchiectomized and infected animals displayed elevated triglyceride levels, as well as a more vigorous immune response, with higher splenocyte proliferation and elevated concentrations of NO. Ovariectomy resulted in an impaired immune response, as observed by a reduction of splenocyte proliferation and NO concentration. The results suggest a pivotal role for gonadal hormones in the modulation of triglyceride levels and the magnitude of the immune response during the acute phase of T. cruzi infection.
