Comparison of the responses of three rat intestinal epithelial cell lines to angiotensin II.
Like RIE-1 cells, two of the IEC series of rat intestinal epithelial cell lines were found to express functional angiotensin receptors. As in RIE-1 cells, treatment of IEC-6 or IEC-18 cells with angiotensin II (AII) activated phosphatidylinositol-4,5-bisphosphate (PIP2) hydrolysis although (in contrast to RIE-1 cells) the magnitude of AII-induced PIP2 hydrolysis was small and not associated with a mitogenic response in either IEC cell line. In terms of their other functional responses to AII (activation of protein kinase C (PKC) and a small elevation of cyclic AMP), IEC-6 cells are otherwise similar to RIE-1 cells whereas IEC-18 cells exhibit some phenotypic differences to the other two cell types. Thus, whereas IEC-6 and RIE-1 cells each express the AT1 subtype of angiotensin receptor, the higher affinity receptors on IEC-18 cells are 'atypical', being insensitive to both AT1- and AT2-specific angiotensin receptor antagonists. Furthermore, in contrast to its effects in IEC-6 and RIE-1 cells, AII neither activates PKC nor modulates cyclic AMP levels in IEC-18 cells. Whereas IEC-18 cells express the myristoylated alanine-rich C-kinase substrate (MARCKS), immunoreactive MARCKS was not detected in IEC-6 or RIE-1 cells.
Smith
R D
RD
Department of Clinical Biochemistry, Addenbrooke's Hospital, Cambridge, U.K.
D000804:Angiotensin II / Q000494:pharmacology*; D000818:Animals; D002455:Cell Division / Q000187:drug effects; D002460:Cell Line; D000242:Cyclic AMP / Q000032:analysis / Q000502:physiology; D004789:Enzyme Activation / Q000187:drug effects; D004847:Epithelial Cells; D004848:Epithelium / Q000737:chemistry / Q000187:drug effects; D007422:Intestines / Q000737:chemistry / Q000166:cytology* / Q000187:drug effects; D007457:Iodine Radioisotopes; D010641:Phenotype; D010766:Phosphorylation; D011493:Protein Kinase C / Q000032:analysis / Q000378:metabolism / Q000502:physiology; D051381:Rats
D007457:Iodine Radioisotopes; D000804:Angiotensin II; D000242:Cyclic AMP; D011493:Protein Kinase C