title: Involvement of guanylate cyclase and phosphodiesterases in the functional heterogeneity of human blood platelet subpopulations.
abstract: Cyclic nucleotides are involved in the regulation of platelet activation, shape change, and aggregation. In this study we have investigated the role of guanylate cyclase and phosphodiesterase in three functional heterogeneous human blood platelet subpopulations separated according to density. In low-density platelets aggregation was enhanced and inhibited less when cyclic GMP was increased by sodium nitroprusside, compared to high-density platelets. Low-density platelets possessed a lower basal level of cyclic GMP and exhibited a small increase in cyclic GMP after stimulation with sodium nitroprusside. Cyclic GMP-dependent phosphodiesterase activity was similar in high, low, and intermediate-density platelets. In contrast, the activity of the cyclic AMP-dependent phosphodiesterase was higher in low-density compared to high and intermediate-density platelets. These results suggest that regulation of cyclic GMP and cyclic AMP levels plays an important role in the functional heterogeneity of human blood platelets.
authors.affiliation: Institute of Physiological Chemistry, University of Marburg, Germany.
authors.forename: C
authors.initials: C
authors.lastname: Opper
authors.forename: E
authors.initials: E
authors.lastname: Schrumpf
authors.forename: A R
authors.initials: AR
authors.lastname: Gear
authors.forename: W
authors.initials: W
authors.lastname: Wesemann
mesh_terms: D000704:Analysis of Variance; D001792:Blood Platelets / Q000187:drug effects / Q000201:enzymology*; D000242:Cyclic AMP / Q000378:metabolism; D006152:Cyclic GMP / Q000096:biosynthesis; D006162:Guanylate Cyclase / Q000187:drug effects / Q000378:metabolism*; D006801:Humans; D009599:Nitroprusside / Q000494:pharmacology; D010727:Phosphoric Diester Hydrolases / Q000187:drug effects / Q000378:metabolism*; D010974:Platelet Aggregation / Q000187:drug effects; D015290:Second Messenger Systems / Q000502:physiology
chemical_list: D009599:Nitroprusside; D000242:Cyclic AMP; D010727:Phosphoric Diester Hydrolases; D006162:Guanylate Cyclase; D006152:Cyclic GMP