Suramin and reactive blue 2 are antagonists for a newly identified purinoceptor on rat megakaryocyte.
1. The effects of purinoceptor antagonists on ATP-induced oscillatory K(+)-currents in rat isolated megakaryocytes were investigated. 2. Both reactive blue-2 (RB-2), a selective antagonist of the P2Y purinoceptor, purinoceptor, at concentrations of 0.3-10 microM and suramin, a non-selective P2 purinoceptor antagonist, at 1-30 microM blocked the ATP-induced oscillation in a concentration-dependent manner. 3. RB-2 and suramin also blocked the ADP-induced K(+)-current oscillation at the same concentration range as in the case of ATP. However, both suramin and RB-2 had no effect on thrombin- and inositol 1,4,5-trisphosphate (IP3)-induced K+ current oscillation, indicating that they act as specific purinoceptor antagonists. 4. Thus, the purinoceptors on megakaryocytes show the properties of the P2 subtype according to their blockade by antagonists.
Uneyama
H
H
Department of Neurophysiology, Tohoku University School of Medicine, Sendai, Japan.
Uneyama
C
C
Ebihara
S
S
Akaike
N
N
D000244:Adenosine Diphosphate / Q000494:pharmacology; D000255:Adenosine Triphosphate / Q000494:pharmacology; D000818:Animals; D004305:Dose-Response Relationship, Drug; D004594:Electrophysiology; D005260:Female; D015544:Inositol 1,4,5-Trisphosphate / Q000494:pharmacology; D007473:Ion Channels / Q000187:drug effects; D008297:Male; D008533:Megakaryocytes / Q000187:drug effects / Q000378:metabolism*; D011188:Potassium / Q000378:metabolism; D011500:Protein Synthesis Inhibitors / Q000494:pharmacology*; D058914:Purinergic Antagonists; D051381:Rats; D017208:Rats, Wistar; D013498:Suramin / Q000494:pharmacology*; D013917:Thrombin / Q000494:pharmacology; D014227:Triazines / Q000494:pharmacology*
D007473:Ion Channels; D011500:Protein Synthesis Inhibitors; D058914:Purinergic Antagonists; D014227:Triazines; C012842:Cibacron Blue F 3GA; D013498:Suramin; D000244:Adenosine Diphosphate; D015544:Inositol 1,4,5-Trisphosphate; D000255:Adenosine Triphosphate; D013917:Thrombin; D011188:Potassium