Effect of hormones and their precursors on protozoa-the selective responsiveness of tetrahymena

G. Csaba, G. Németh

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1. 1. Among the thyroxine precursors diiodothyrosine, and in the serotonin series serotonin, had the strongest growth enhancing effect on Tetrahymena. 2. 2. The toxicity of tyrosine was directly related to the number of iodine atoms present in the molecule. 3. 3. The basic amino acid molecules exerted a concentration-dependent growth-promoting effect on Tetrahymena. 4. 4. The experimental observations suggest that while serotonin, had a more active influence on Tetrahymena than its precursors, the vertebrate hormone thyroxine was inferior in activity to its precursors, which also appear at lower levels of phylogenesis. 5. 5. This suggests the presence of hormone receptors in Tetrahymena, but also the phylogenetic immaturity of these.

Original languageEnglish
Pages (from-to)387-390
Number of pages4
JournalComparative Biochemistry and Physiology - B Biochemistry and Molecular Biology
Issue number2
Publication statusPublished - 1980


ASJC Scopus subject areas

  • Medicine(all)

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