A general response to stressors by the unicellular Tetrahymena: effect of stress on the hormone levels.

ABSTRACT

Hormone (ACTH, endorphin, serotonin and T(3)) content of the unicellular Tetrahymena was studied by using immunocytochemical and flow cytometry methods. The cells were previously treated with different concentrations of salts (NaCl or KCl for 1 h), were kept in low (+4 degrees C) or high (+37 degrees C) temperature for 1 h and were treated with formaldehyde or ethanol. High concentrations of salts (20 mg ml(-1) medium), all levels (0.1, 0.05, 0.01%) of formaldehyde and high temperature almost doubled the hormone contents and 0.1% alcohol also significantly elevated them. The experiments call attention to the presence of a general adaptation syndrome (GAS)-like phenomenon at a unicellular level and points to the possibility of deduction of GAS to a low level of phylogeny.