Zymosan-induced release of inositol phosphates at resting cytosolic Ca2+ concentrations in macrophages.
Hydrolysis of polyphosphoinositides by phosphodiesterase has been demonstrated to be involved in the control of cytosolic Ca2+ concentrations. The stimulation of Ca2+ ionophores of the release of inositol phosphates in macrophages, and other cells, together with the Ca2+ requirements for zymosan-induced phospholipase C activation, make unclear the relationship between Ca2+ mobilization and polyphosphoinositide hydrolysis. The results in the present paper strongly suggest that, for zymosan-induced phospholipase C activation, a previous increase in cytosolic Ca2+ is not a required event. These results also show that zymosan-activated release of inositol phosphates may be mediated by a guanine-nucleotide-binding protein.
D000818:Animals; D000001:Calcimycin / Q000494:pharmacology; D002118:Calcium / Q000378:metabolism*; D003600:Cytosol / Q000378:metabolism; D007295:Inositol Phosphates / Q000378:metabolism*; D008264:Macrophages / Q000187:drug effects / Q000378:metabolism*; D010713:Phosphatidylcholines / Q000378:metabolism; D010714:Phosphatidylethanolamines / Q000378:metabolism; D013403:Sugar Phosphates / Q000378:metabolism*; D013552:Swine; D010738:Type C Phospholipases / Q000378:metabolism; D015054:Zymosan / Q000494:pharmacology*
D007295:Inositol Phosphates; D010713:Phosphatidylcholines; D010714:Phosphatidylethanolamines; D013403:Sugar Phosphates; D000001:Calcimycin; D015054:Zymosan; D010738:Type C Phospholipases; D002118:Calcium