TY - JOUR
T1 - A low molecular weight brain substance interacts, similarly to clonidine, with α2-adrenoceptors of human platelets
AU - Diamant, Sophia
AU - Eldor, Amiram
AU - Atlas, Daphne
PY - 1987/12/15
Y1 - 1987/12/15
N2 - In the present study, we explored the effects of a clonidine-displacing substance (CDS) which was isolated and partially purified from bovine brain. The low molecular weight brain substance competes with clonidine and rauwolscine in rat brain membranes, and mimics clonidine's inhibitory action in rat vas deferens. We find that CDS competes with [3H]rauwolscine-labeled α2-adrenoceptors in human platelets. Further characterization of CDS in human platelets reveals that, like clonidine, it inhibits the epinephrine-induced aggregation, potentiates the ADP- and the collagen-induced aggregation however, by itself, CDS is unable to induce aggregation. Unlike clonidine, CDS does not affect the prostacyclin (PGI2)-stimulated cAMP accumulation in intact platelets. The presence of CDS in human plasma, as we have recently shown, implies a possible role of CDS in the regulation of platelet action.
AB - In the present study, we explored the effects of a clonidine-displacing substance (CDS) which was isolated and partially purified from bovine brain. The low molecular weight brain substance competes with clonidine and rauwolscine in rat brain membranes, and mimics clonidine's inhibitory action in rat vas deferens. We find that CDS competes with [3H]rauwolscine-labeled α2-adrenoceptors in human platelets. Further characterization of CDS in human platelets reveals that, like clonidine, it inhibits the epinephrine-induced aggregation, potentiates the ADP- and the collagen-induced aggregation however, by itself, CDS is unable to induce aggregation. Unlike clonidine, CDS does not affect the prostacyclin (PGI2)-stimulated cAMP accumulation in intact platelets. The presence of CDS in human plasma, as we have recently shown, implies a possible role of CDS in the regulation of platelet action.
KW - Clonidine
KW - Clonidine-displacing substance (CDS)
KW - Platelets (human)
KW - α-Adrenoceptors
UR - http://www.scopus.com/inward/record.url?scp=0023555080&partnerID=8YFLogxK
U2 - 10.1016/0014-2999(87)90377-3
DO - 10.1016/0014-2999(87)90377-3
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C2 - 2831067
AN - SCOPUS:0023555080
SN - 0014-2999
VL - 144
SP - 247
EP - 255
JO - European Journal of Pharmacology
JF - European Journal of Pharmacology
IS - 3
ER -