title: Partial agonist behaviour of adenosine 5'-O-(2-thiodiphosphate) on human platelets.
abstract: 1 The effects of an adenosine diphosphate (ADP) analogue, adenosine 5'-O-(2-thiodiphosphate) (ADP-beta-S), in which a terminal phosphate oxygen has been replaced by sulphur, were studied on human platelets. 2 ADP-beta-S induced platelet aggregation and inhibited prostaglandin E1 (PGE1)-stimulated adenylate cyclase but in both cases was less potent than ADP and did not achieve the same maximal effects. 3 Both actions of ADP could be inhibited by the simultaneous addition of ADP-beta-S (50 microM). 4 Aggregation induced by 11 alpha, 9 alpha-epoxymethano prostaglandin H2 (a stable endoperoxide analogue) was not inhibited by simultaneous addition of ADP-beta-S (50 microM). 5 The behaviour of ADP-beta-S towards human platelets was consistent with it being a partial agonist.
mesh_terms: D000244:Adenosine Diphosphate / Q000031:analogs & derivatives* / Q000494:pharmacology; D000255:Adenosine Triphosphate / Q000494:pharmacology; D001792:Blood Platelets / Q000187:drug effects*; D006801:Humans; D066298:In Vitro Techniques; D009711:Nucleotides / Q000378:metabolism; D010974:Platelet Aggregation / Q000187:drug effects; D011450:Prostaglandin Endoperoxides, Synthetic / Q000494:pharmacology; D011458:Prostaglandins E / Q000037:antagonists & inhibitors; D011463:Prostaglandins H / Q000494:pharmacology; D013873:Thionucleotides / Q000494:pharmacology*
chemical_list: D009711:Nucleotides; D011450:Prostaglandin Endoperoxides, Synthetic; D011458:Prostaglandins E; D011463:Prostaglandins H; D013873:Thionucleotides; C030812:adenosine 5'-O-(2-thiodiphosphate); D000244:Adenosine Diphosphate; D000255:Adenosine Triphosphate