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Comparison of the insulin binding, uptake and endogeneous insulin content in long‐ and short‐term starvation in Tetrahymena
Author(s) -
Csaba G.,
Kovács P.,
Pállinger Éva
Publication year - 2008
Publication title -
cell biochemistry and function
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.933
H-Index - 61
eISSN - 1099-0844
pISSN - 0263-6484
DOI - 10.1002/cbf.1399
Subject(s) - starvation , tetrahymena , insulin , endogeny , biology , tetrahymena pyriformis , flow cytometry , endocrinology , receptor , insulin receptor , medicine , microbiology and biotechnology , biochemistry , insulin resistance
FITC‐insulin binding and endogeneous insulin content of Tetrahymena pyriformis , that had been 24 h or 30 min starved, continuously fed or re‐fed after starvation was studied by flow cytometry and confocal microscopy. Long starvation elevated both insulin binding and endogeneous insulin content of the cells. Short re‐feeding after long starvation or short starvation after continuous feeding does not change the situation. Fixed cells also bind FITC‐insulin, however, in this case long starvation reduces, and re‐feeding after long starvation elevates, the binding, which means that hormone binding by receptors only differs from receptor binding and engulfment (in living cells). The increase of FITC‐insulin content in living cells seems to be due to engulfment, rather than by receptor binding. The results point to the unicellular organism's requirement for insulin production and binding in a life‐threatening stress situation. Copyright © 2007 John Wiley & Sons, Ltd.