La tuberculose humaine à bacille bovin dans le monde

Hublart Maurice, Moine Gilbert. La tuberculose humaine à bacille bovin dans le monde. In: Bulletin de l'Académie Vétérinaire de France tome 122 n°1, 1969. pp. 53-58

Prophylaxie de la tuberculose bovine II. — Exigences et difficultés de la finition (suite)

Moine Gilbert, Hublart Maurice. Prophylaxie de la tuberculose bovine. II. Exigences et difficultés de la finition (suite). In: Bulletin de l'Académie Vétérinaire de France tome 122 n°5, 1969. pp. 211-218

A high corticosterone/DHEA-s ratio in young rats infected with Trypanosoma cruzi is associated with increased susceptibility

We have previously established that young male rats are more susceptible to the effects of Trypanosoma cruzi infection than adult rats. To explore underlying age-associated differences in disease outcome, we simultaneously assessed hormone levels and cytokine release throughout the acute infection period in young and adult rats infected with T. cruzi. Young rats were inoculated with 1 x 10(6) and adult rats with 7 x 10(6) blood trypomastigotes, according to their relative body weight. At zero, seven, 14, 21 and 28 days after infection, blood was collected for the determination of gonadal and adrenal hormones, tumor necrosis factor α (TNF-α), interleukin (IL)-10 and specific IgM and IgG subtypes. Young animals displayed significantly higher parasitaemia values and an endocrine pattern that was characterised by elevated values in corticosterone (CT) and the CT/dehydroepiandrosterone-sulfate ratio, which favours immunosuppression and susceptibility. In contrast, adult male rats were able to restrict the parasite burden, which likely resulted from increased IgG antibody synthesis and oestradiol levels. Adult rats also showed a reduced TNF-α/IL-10 ratio and less tissue damage. We conclude that young animals exhibited increased vulnerability to T. cruzi infection compared with adults and this is associated with an unsuitable immunoendocrine milieu