Elevation of calcium in rat enterocytes byEscherichia coli heat-stable (STa) enterotoxin

Enteric bacterial toxins: mechanisms of action and linkage to intestinal secretion.

“…Most recently, the I sc response of human intestine to STa was not inhibited by the cyclooxygenase inhibitor indomethacin, suggesting that prostaglandins do not mediate the secretory response to STa (296). In addition, on the basis of inhibitor studies and studies with isolated rat intestinal epithelial cells, a role for phosphatidylinositol and diacylglycerol release with elevation of intracellular calcium levels and activation of PKC has been proposed to be important in STa-stimulated secretion (16,17,60,61,174,191,286,287,530). Although in vitro studies have shown release of these potential secretory mediators, correlation with a secretory response is not yet available.…”

Diarrhea or colorectal cancer: Can bacterial toxins serve as a treatment for colon cancer?

“…In this respect, calcium does play a pivotal role. It should be noted that most, if not all, of the studies showing rise of [Ca 2ϩ ] int by STa have been restricted to the enterocytes of animals (25,26). On the other hand, reports in T84 colon cancer cells and colonic epithelia are inconsistent.…”