Evaluation of Caiman latirostris as a sentinel of environmental contamination with xenoestrogens

STOKER, C.; BUSSMANN, L.; SIROSKI, P.A.; LARRIERA, A; LUQUE, E.H.; MUÑOZ DE TORO, M.M.

Rosario

Congreso; 21 Annual Meeting of Rosario Biology Society; 2001

Sociedad de Biología de Rosario

Environmental contamination with xenoestrogens produces adverse effects in wildlife and human inducing endocrine disruption. Caiman latirostris (yacaré overo) has characteristics that could make it suitable as a sentinel. Our objective was to characterize the response to 17b-estradiol (E2) in Caiman latirostris females target organs. Juvenil females were injected sc with E2 (1mg/g) daily for 7 days and every other day until day 21 (D21). Controls received sesame oil. Plasma was collected on D0 and D23 of treatment. Gonads obtained on D23 were fixed in formol-buffer and paraffin embedded. Protein induction by E2 was studied in one-dimention PAGE-SDS gels. Gels were stained with Coomasie Blue and Stains-All. Epithelium thickness of Müllerian duct was quantified by image analysis in 5mm H&E stained sections. E2 treated group showed a protein band » 200kDa, which was identified as a phosphoprotein with Stains-All dye. This protein could be isolated from diluted plasma by addition of EDTA and Mg2+. Müllerian duct ephitelium thickness was higher in E2 treated group (57.0mm±8.6) than in control (14.9mm±0.6), showing hypertrophy and hyperplasia. E2 treatment in Caiman latirostris induces changes in target organs that could be also sensitive to environmental xenoestrogens. A complete characterization of male and female response to xenoestrogen will permit the use of yacaré as a sentinel to assess contaminations by endocrine disrupters.