Investigation of the mechanisms of platelet activation mediated through adrenoceptors.
ADP induced membrane reorganization leading to an increase in membrane microviscosity with the decrease in the distance between protein globules and membrane surface. Adrenaline at low concentrations enhanced the ADP-induced platelet aggregation and deepened the structural reorganization. Analogous phenomenon was induced by the selective alpha 2-adrenoceptor agonist azopexole. The selective alpha 2-adrenoceptor antagonist idazoxan eliminated the effects of both adrenaline and azopexole. It is suggested that alpha 2-adrenoceptor activation leads to an increase in the number of fibrinogen receptors on platelet membranes due to the more pronounced advancement of membrane proteins to the membrane surface.
Gabrielian
E S
ES
Department of Pharmacology, Erevan Medical Institute, Armenia, USSR.
Akopov
S E
SE
Ayvasian
A G
AG
D000244:Adenosine Diphosphate / Q000494:pharmacology; D002462:Cell Membrane / Q000502:physiology; D004837:Epinephrine / Q000494:pharmacology; D005454:Fluorescence Polarization; D006801:Humans; D066298:In Vitro Techniques; D008560:Membrane Fluidity / Q000187:drug effects; D015539:Platelet Activation / Q000502:physiology*; D010974:Platelet Aggregation / Q000187:drug effects; D011941:Receptors, Adrenergic / Q000502:physiology*; D014783:Viscosity
D011941:Receptors, Adrenergic; D000244:Adenosine Diphosphate; D004837:Epinephrine