Hormonal changes in Trypanosoma evansi-infected Rattus norvegicus: An approach to understand host-parasite interaction

Abstract

Background: Several studies were conducted on T. evansi infections in camels, but its pathogenesis is still mysterious especially in association with hormonal and infertility problems. Objective: The present research aimed to monitor the endocrine changes associated with T. evansi infection and its relation to immunity. Material and Methods: Twenty-four rats were used, four of them were considered the control group (CG), and the others were infected with T. evansi (IG). Blood samples were collected from CG at 0 day, while blood samples and testicular specimens were collected from IG on the 7 th , 14 th , 21 st , 28 th , and 35 th day (4 rats each time period). Cytokines, hormones, minerals, and electrolytes were measured, and the testicular specimens were sectioned, stained, and microscopically examined. Results: There was a significant increase in the pro-inflammatory cytokines accompanied by significant (P˂0.05) hypercortisolemia, increased growth hormone (GH) and thyroid stimulating hormone (TSH) levels, hypothyroidism, hypoinsulinemia, decreased testosterone, minerals, and electrolytes concentrations. Pro-inflammatory cytokines positively correlated with cortisol, growth hormone, and TSH and negatively correlated with T3, T4, insulin, and testosterone. The measured hormones yielded good values of sensitivity, specificity, and accuracy rate. The histopathological examination of the testicular tissue showed degeneration and necrosis of the spermatocytes and seminiferous tubules and hyperplasia of the interstitial tissue with edema, congestion, and infiltration. Conclusion:The recorded immunological changes during trypanosomiasis are strongly associated with the hormonal changes and infertility, and decreased minerals and electrolytes levels. Cortisol, T3, T4, and GH are proposed good indicators of trypanosomiasis.