The NK1 receptor is involved in the neurokinin-induced shape change of rabbit platelets.
Substance P and selective neurokinin receptor agonists have been tested for their ability to induce shape change in rabbit platelets. Substance P and the NK1 receptor agonist Ac [Arg6,Sar9,Met(O2)11]-substance P (6-11) induced shape change (EC50 = 3 and 6 nM, respectively), whereas the selective NK2 agonist [Nle10]-Neurokinin A (4-10) and the selective NK3 agonist [MePhe7]-Neurokinin B did not show any effect. Moreover, the specific NK1 receptor antagonist CP-96,345 selectively and dose-dependently counteracted the effect of substance P or of the NK1 receptor agonist (IC50 = 2 and 0.8 nM, respectively), whereas the selective NK2 receptor antagonist, SR 48968, had no effect. Unlike for serotonin or low doses of ADP, epinephrine did not allow substance P or the NK1 receptor agonist to become a proaggregating substance. These data therefore show that the NK1 receptor is solely involved in the neurokinin-induced shape change of rabbit platelets.
Savi
P
P
Sanofi Recherche, Toulouse, France.
Laplace
M C
MC
Le Fur
G
G
Emonds-Alt
X
X
Herbert
J M
JM
D000818:Animals; D001792:Blood Platelets / Q000166:cytology* / Q000378:metabolism; D008297:Male; D011817:Rabbits; D018041:Receptors, Neurokinin-2; D017981:Receptors, Neurotransmitter / Q000037:antagonists & inhibitors / Q000378:metabolism*; D013373:Substance P / Q000031:analogs & derivatives / Q000378:metabolism*
D018041:Receptors, Neurokinin-2; D017981:Receptors, Neurotransmitter; D013373:Substance P