Presence (hPL, prostaglandin) and absence (triiodothyronine, thyroxine) of hormones in Tetrahymena: experimental facts and open questions
Csaba, G.; Nagy, S.U.
Acta Physiologica Hungarica 70(1): 105-110
1987
ISSN/ISBN: 0231-424X PMID: 3425324 Document Number: 297112
The RIA technique detected prostaglandin (PGF2) and human placetal lactogen (hPL) in Tetrahymena cultures grown in bacto tryptone + yeast extract medium which, however, itself contained these hormones. About one to two per cent of the total hormone content of the medium was demonstrated intracellularly. Treatment with diiodotyrosine (T2), which is known to stimulate the growth of Tetrahymena, was followed by a decrease in the intracellular prostaglandin level. Triiodothyronine and thyroxine were not detected in Tetrahymena or in the medium, and did not appear in it on induction with TSH either. In the light of these observations it might well be doubted that prostaglandin was native in Tetrahymena: the use of synthetic media, and/or a reliable demonstration of the hormone content of the growth medium is recommended for evidence of hormone biosynthesis by unicellular organisms.