In vitro effect of endothelin-1 on collagen, and ADP-induced aggregation in human whole blood and platelet rich plasma.
The effect of ET-1 on ADP- and collagen-induced platelet aggregation in whole blood and platelet rich plasma (PRP) was studied in 39 healthy volunteers. Although ET-1 itself did not cause platelet aggregation, a marked enhancement of ADP-induced aggregation after the preincubation with ET-1 for 5 min was observed in whole blood, but not in PRP. This ET-1 concentration and preincubation time-dependent phenomenon could be demonstrated only at threshold concentrations (5 and 7.5 microM) of ADP and is probably due to an interaction of ET-1 with cells which are involved in the whole blood aggregation, such as polymorphonuclear neutrophils. In whole blood and PRP an inhibition of collagen-induced aggregation after the preincubation with ET-1 was detected. In contrast to ADP, a direct influence of ET-1 on platelet activation after the addition of collagen is therefore more likely. These results suggest that human platelets may possess ET-1 receptor(s) and that ET-1 may also interact with other blood cells.
Knöfler
R
R
Department of Physiology, Hamamatsu University School of Medicine, Shizuoka, Japan.
Urano
T
T
Malyszko
J
J
Takada
Y
Y
Takada
A
A
D000244:Adenosine Diphosphate / Q000494:pharmacology*; D000293:Adolescent; D000328:Adult; D001769:Blood / Q000187:drug effects*; D003094:Collagen / Q000494:pharmacology*; D004357:Drug Synergism; D016232:Endothelins / Q000494:pharmacology*; D006801:Humans; D010949:Plasma / Q000187:drug effects*; D010974:Platelet Aggregation / Q000187:drug effects*; D010976:Platelet Count
D016232:Endothelins; D000244:Adenosine Diphosphate; D003094:Collagen