title: Hydrolysis of cyclic GMP in rat peritoneal macrophages.
abstract: Intact rat peritoneal macrophages (rPM) treated with 3-isobutyl-1-methylxanthine (IBMX), an inhibitor of phosphodiesterases (PDEs), accumulated more cGMP than untreated cells. A PDE activity toward [(3)H]cGMP was detected in the soluble and particulate fractions of rPM. The hydrolysis of cGMP was Ca(2+)/calmodulin-independent but increased in the presence of cGMP excess. Similar results were obtained when [(3)H]cAMP was used as a substrate. The hydrolytic activity towards both nucleotides was inhibited in the presence of IBMX. Therefore, the PDEs of families 2, 5, 10 and 11 are potential candidates for cGMP hydrolysis in the rPM. They may not only regulate the cGMP level in a feedback-controlled way but also link cGMP-dependent pathways with those regulated by cAMP.
authors.affiliation: Laboratory of Signaling Proteins, L Hirszfeld Institute of Immunology and Experimental Therapy, Polish Academy of Sciences, Wrocław, Poland.
authors.forename: Hanna
authors.initials: H
authors.lastname: Witwicka
authors.forename: Marcin
authors.initials: M
authors.lastname: Kobiałka
authors.forename: Wojciech A
authors.initials: WA
authors.lastname: Gorczyca
mesh_terms: D015056:1-Methyl-3-isobutylxanthine / Q000494:pharmacology; D000818:Animals; D009320:Atrial Natriuretic Factor / Q000494:pharmacology; D002118:Calcium / Q000378:metabolism; D002147:Calmodulin / Q000378:metabolism; D002478:Cells, Cultured; D006152:Cyclic GMP / Q000378:metabolism* / Q000494:pharmacology; D006868:Hydrolysis; D017737:Macrophages, Peritoneal / Q000187:drug effects / Q000378:metabolism*; D008297:Male; D010726:Phosphodiesterase Inhibitors / Q000494:pharmacology; D010727:Phosphoric Diester Hydrolases / Q000378:metabolism; D051381:Rats; D017208:Rats, Wistar; D012995:Solubility
chemical_list: D002147:Calmodulin; D010726:Phosphodiesterase Inhibitors; D009320:Atrial Natriuretic Factor; D010727:Phosphoric Diester Hydrolases; D006152:Cyclic GMP; D002118:Calcium; D015056:1-Methyl-3-isobutylxanthine