Calcium-dependent prostaglandin biosynthesis by lipopolysaccharide-stimulated rat Kupffer cells.
Isolated rat Kupffer cells produced and released prostaglandin (PG) E2, 6-keto-PGF1 alpha, and thromboxane B2 (TXB2) in response to lipopolysaccharide (LPS) stimulation. This elevation of PGE2, 6-keto-PGF1 alpha and TXB2 in the medium was not observed when cells were cultured in the absence of extracellular calcium or in the presence of an extracellular calcium chelator, EGTA. An intracellular calcium antagonist, TMB-8, also suppressed the production of PGE2, 6-keto-PGF1 alpha and TXB2 in a concentration-dependent manner. The intra-cellular calcium concentration of Kupffer cells elevated early after the addition of LPS determined by the use of fura-2 and a fluorescence microscopy. Moreover, calmodulin inhibitors, W-7 and W-13, apparently inhibited the production of PGF2, 6-keto-PGF1 alpha and TXB2. All these results suggest that LPS-induced PG production by stimulated rat Kupffer cells may be regulated by a calcium-calmodulin pathway.
Kawada
N
N
Third Department of Internal Medicine, Osaka City University Medical School, Japan.
Mizoguchi
Y
Y
Kobayashi
K
K
Monna
T
T
Morisawa
S
S
D015121:6-Ketoprostaglandin F1 alpha / Q000096:biosynthesis; D000818:Animals; D000001:Calcimycin / Q000494:pharmacology; D002118:Calcium / Q000378:metabolism / Q000494:pharmacology; D002147:Calmodulin / Q000037:antagonists & inhibitors / Q000378:metabolism; D003600:Cytosol / Q000187:drug effects / Q000378:metabolism; D015232:Dinoprostone / Q000096:biosynthesis; D004533:Egtazic Acid / Q000494:pharmacology; D066298:In Vitro Techniques; D007728:Kupffer Cells / Q000187:drug effects* / Q000378:metabolism; D008070:Lipopolysaccharides / Q000494:pharmacology*; D008297:Male; D011453:Prostaglandins / Q000096:biosynthesis*; D051381:Rats; D017208:Rats, Wistar; D013929:Thromboxane B2 / Q000096:biosynthesis
D002147:Calmodulin; D008070:Lipopolysaccharides; D011453:Prostaglandins; D000001:Calcimycin; D004533:Egtazic Acid; D013929:Thromboxane B2; D015121:6-Ketoprostaglandin F1 alpha; D015232:Dinoprostone; D002118:Calcium