Sodium regulation of alpha 2-adrenoreceptors of human platelets: inactivation by 4,4'-diisothiocyano-2,2'-stilbene disulfonic acid (DIDS).
In the present study, we investigated the effect of DIDS on Na+ regulation of alpha 2-adrenoreceptors in human platelets. Pretreatment of platelet membranes at 23 degrees C for 60 min with DIDS produced a reduction in the affinity of the receptors for both antagonist and agonist in a concentration related manner; however, there was a marked difference in the degree of reduction in the affinity of the receptors for antagonist and agonist. Thus, at 1 mM concentration of DIDS, the affinity of the receptors for antagonist was reduced by 2-fold while the affinity of the receptors for agonist was reduced by 14-fold. Furthermore, this concentration of DIDS abolished the ability of Na+ in reducing the affinity of the receptors for agonist. We suggest that the effect of DIDS is via Na+ binding component of the alpha 2-adrenoreceptor-adenylate cyclase complex.
D017878:4,4'-Diisothiocyanostilbene-2,2'-Disulfonic Acid; D012856:4-Acetamido-4'-isothiocyanatostilbene-2,2'-disulfonic Acid / Q000031:analogs & derivatives / Q000494:pharmacology*; D001792:Blood Platelets / Q000187:drug effects* / Q000378:metabolism; D002462:Cell Membrane / Q000378:metabolism; D006801:Humans; D007473:Ion Channels / Q000187:drug effects; D007700:Kinetics; D011943:Receptors, Adrenergic, beta / Q000378:metabolism*; D012964:Sodium / Q000502:physiology*; D013267:Stilbenes / Q000494:pharmacology*; D015016:Yohimbine / Q000378:metabolism
D007473:Ion Channels; D011943:Receptors, Adrenergic, beta; D013267:Stilbenes; D012856:4-Acetamido-4'-isothiocyanatostilbene-2,2'-disulfonic Acid; D015016:Yohimbine; D012964:Sodium; D017878:4,4'-Diisothiocyanostilbene-2,2'-Disulfonic Acid