EFFECTS OF HYDROCORTISONE ON THE LYMPHOID ORGANS OF RANA-TEMPORARIA

In vivo and in vitro effects' of hydrocortisone hemisuccinate (HC) on the lymphoid organs were studied in the European common frog Rana temp oraria. Single HC injection at the dose of 0.5 mg/g body weight induce d rapid but fully reversible changes in thymuses and jugular bodies wh ile its effect on spleens was negligible. In vitro studies confirmed H C-sensitivity of thymuses and jugular bodies and relative HC-resistanc e of spleens of this species. In vitro exposition of thymic and jugula r body cell suspensions to 0.25-1.00 mg/ml HC solution revealed a dose -dependent and time-dependent impairment of sample activities associat ed with massive cell death as judged by MTT reduction assay and Trypan blue uptake, respectively. Evolutionary implications of these results are discussed.