Altered levels of hypothalamic-pituitary-adrenocortical axis hormones in baboons and mice during the course of infection with Schistosoma mansoni

Baboons with primary or secondary exposure to Schistosoma mansoni were comp ared with each other over a 12- week infection period and with baseline val ues obtained from uninfected baboons with respect to serum levels of the hy pothalamic- pituitary- adrenal (HPA) axis hormones- corticotropin- releasin g hormone, adrenocorticotropic hormone, dehydroepiandrosterone sulfate (DHE A- S), and cortisol. Baboons with primary infections, when worm recovery an d oviposition rates were high and hepatic schistosome egg granulomas were l arge, had decreasing levels of these hormones as infection progressed, comp ared with both uninfected and reexposed baboons. The most reduced hormone l evel was that of DHEA- S. Reduction of DHEA- S and cortisol levels also occ urred in primary murine infections. Reexposed baboons with low worm recover y and oviposition rates and small (modulated) hepatic granulomas showed the opposite pattern: HPA axis hormone levels were maintained at, or exceeded, the baseline values of uninfected baboons. These results suggest that HPA axis hormones may play a role in regulating the establishment, maturation, and oviposition of schistosomes and the progression of schistosomiasis.