C. Uneyama et al., KINETIC CHARACTERISTICS OF THROMBIN RECEPTOR-MEDIATED RESPONSES IN RAT MEGAKARYOCYTES, European journal of pharmacology, 319(2-3), 1997, pp. 299-305
Kinetic characteristics of thrombin receptor-mediated responses on rat
megakaryocytes were examined by the use of the perforated patch clamp
combined with the rapid drug exchange system termed the 'Y-tube metho
d'. The application of thrombin evoked repetitive Ca2+-activated K+ cu
rrent (I-KCa) in a concentration-dependent manner. The characteristic
features for thrombin-induced response compared with purinoceptor-indu
ced response were the long latency, long washout time and fast desensi
tization. The similar I-KCa as thrombin was induced by trypsin. Thromb
in- and trypsin-induced I-KCa were both inhibited by the protease inhi
bitor, SBTI, and the washout time for thrombin was markedly shortened
(7.4 +/- 2.2 s) when thrombin was washed out by a solution containing
soybean trypsin inhibitor. A synthetic thrombin receptor agonist pepti
de induced I-KCa oscillation with shorter latency than thrombin.