title: Regulation of human erythrocyte Na+/H+ exchange by soluble and particulate guanylate cyclase.
abstract: Guanylate cyclase activity in human erythrocytes is investigated by evaluating the intracellular guanosine 3',5'-cyclic monophosphate (cGMP) content in the presence of various agents that exert specific effects on soluble or particulate guanylate cyclase. The increase in the intraerythrocyte cGMP content by the soluble guanylate cyclase activators nitroprusside and NaNO2 suggests the presence of this enzyme in human erythrocytes. The effects of four different atrial natriuretic peptide (ANP) fragments on the intraerythrocyte cGMP content is also studied. ANP II and ANP III increase the intraerythrocyte cGMP content, whereas ANP I and des-Ser5,des-Ser6-ANP III are ineffective. Thus our data show that human erythrocytes possess particulate guanylate cyclase together with the soluble enzyme. The ANP fragments ANP II and ANP III also activate the erythrocyte Na+/H+ exchange. Nitroprusside, M & B 22948 (an inhibitor of cGMP phosphodiesterase), and the cGMP analogues dibutyryl cGMP and 8-bromoguanosine 3',5'-cyclic monophosphate also increase the erythrocyte Na+/H+ exchange rate. The latter data also suggest that the erythrocyte Na+/H+ exchange is regulated by cGMP.
authors.affiliation: Department of Molecular, University of Leuven (Katholieke Universiteit Leuven, Belgium.
authors.forename: V
authors.initials: V
authors.lastname: Petrov
authors.forename: P
authors.initials: P
authors.lastname: Lijnen
mesh_terms: D015106:3',5'-Cyclic-GMP Phosphodiesterases / Q000097:blood; D015124:8-Bromo Cyclic Adenosine Monophosphate / Q000494:pharmacology; D000255:Adenosine Triphosphate / Q000097:blood; D009320:Atrial Natriuretic Factor / Q000494:pharmacology*; D000001:Calcimycin / Q000494:pharmacology; D006152:Cyclic GMP / Q000097:blood; D004789:Enzyme Activation; D004912:Erythrocytes / Q000187:drug effects / Q000378:metabolism*; D006162:Guanylate Cyclase / Q000097:blood*; D006454:Hemoglobins / Q000378:metabolism; D006706:Homeostasis; D006801:Humans; D007700:Kinetics; D008345:Manganese / Q000097:blood / Q000494:pharmacology; D008706:Methemoglobin / Q000378:metabolism; D009599:Nitroprusside / Q000494:pharmacology; D010446:Peptide Fragments / Q000494:pharmacology; D010726:Phosphodiesterase Inhibitors / Q000494:pharmacology; D011688:Purinones / Q000494:pharmacology; D012977:Sodium Nitrite / Q000494:pharmacology; D017923:Sodium-Hydrogen Exchangers / Q000097:blood*
chemical_list: D006454:Hemoglobins; D010446:Peptide Fragments; D010726:Phosphodiesterase Inhibitors; D011688:Purinones; D017923:Sodium-Hydrogen Exchangers; D009599:Nitroprusside; D015124:8-Bromo Cyclic Adenosine Monophosphate; D000001:Calcimycin; D008345:Manganese; D009320:Atrial Natriuretic Factor; D000255:Adenosine Triphosphate; D008706:Methemoglobin; D015106:3',5'-Cyclic-GMP Phosphodiesterases; D006162:Guanylate Cyclase; C011145:zaprinast; D006152:Cyclic GMP; D012977:Sodium Nitrite