Evidence for stimulation of the inositol triphosphate-Ca2+ signalling system in rat enterocytes by heat stable enterotoxin of Escherichia coli.
In Escherichia coli heat stable enterotoxin (STa)-treated rat enterocytes, the rise of inositol triphosphate (IP3) preceded the rise of [Ca2+]i. Chelation of extracellular Ca2+ with EGTA and suspension of cells in Ca2+ free buffer both demonstrated the enterotoxin-induced initial rise of [Ca2+]i with a concomitant loss of sustained phase. Furthermore, pretreatment of cells with dantrolene resulted in a decrease of the early response of [Ca2+]i, indicating the initial effect of the rise of [Ca2+]i was mostly due to its mobilization from some IP3-sensitive intracellular stores.
Chaudhuri
A G
AG
National Institute of Cholera and Enteric Diseases, Beliaghata, Calcutta, India.
Ganguly
U
U
D000818:Animals; D002118:Calcium / Q000378:metabolism*; D004533:Egtazic Acid; D004768:Enterotoxins / Q000494:pharmacology*; D004926:Escherichia coli; D066298:In Vitro Techniques; D015544:Inositol 1,4,5-Trisphosphate / Q000378:metabolism*; D007583:Jejunum / Q000166:cytology / Q000187:drug effects* / Q000378:metabolism; D051381:Rats; D015398:Signal Transduction
D004768:Enterotoxins; D004533:Egtazic Acid; D015544:Inositol 1,4,5-Trisphosphate; D002118:Calcium