Comparison of the insulin binding, uptake and endogenous insulin content in long- and short-term starvation in Tetrahymena.

Abstract

FITC-insulin binding and endogenous 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 endogenous 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.

• Authors: G Csaba, P Kovács, Eva Pállinger
• Journal: Cell biochemistry and function (Cell Biochem Funct) 2008 Jan-Feb Vol. 26 Issue 1 Pg. 64-9 ISSN: 1099-0844 [Electronic] England
• PMID: 17252535 (Publication Type: Comparative Study, Journal Article, Research Support, Non-U.S. Gov't)
• Copyright: 2007 John Wiley & Sons, Ltd.

Chemical References

• Insulin
• insulin, fluorescein-isothiocyanated-
• Receptor, Insulin
• Fluorescein-5-isothiocyanate

Topics

• Animals
• Fluorescein-5-isothiocyanate (analogs & derivatives, metabolism)
• Insulin (analogs & derivatives, metabolism)
• Receptor, Insulin (metabolism)
• Starvation (metabolism)
• Tetrahymena pyriformis (metabolism)
• Time Factors