Cytochemical investigation into the Ca-dependence of positive and negative hormonal imprinting in Tetrahymena

P. Kovács, G. Csaba

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Insulin gives rise to positive imprinting in Tetrahymena pyriformis, but to negative imprinting in T. thermophila, as revealed by the respective increases and decreases in the insulin-binding capacity of these organisms observed during later interactions with this hormone. We found that changes in insulin-binding capacity exhibited parallelism with fluctuations of the levels of free, intracellular Ca2+ detectable by Quin-2 labeling. An exception was the second interaction of T. thermophila with insulin, which although showing a positive trend, produced a relatively small increase in the level of intracellular Ca2+. These observations suggest an interrelationship between hormone-binding capacity and the fluctuation of intracellular Ca2+ levels. Either hormone binding depends on the availability of Ca2+, or, alternatively, the latter depends on the binding capacity. Further studies are required to elucidate the true nature of this interdependence.

Original languageEnglish
Pages (from-to)619-622
Number of pages4
Issue number6
Publication statusPublished - Nov 1 1987


ASJC Scopus subject areas

  • Anatomy
  • Agricultural and Biological Sciences(all)

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