Platelets, endothelium and blood vessel wall.
Aggregating platelets cause contraction of vascular smooth muscle, because they release serotonin and thromboxane A2. If the platelets aggregate in a blood vessel with intact intima, the platelet-products cause endothelium-dependent relaxation of the underlying smooth muscle. Hence, the presence of an intact intima considerably reduces the vasospastic response to platelet-aggregation. The major platelet products which trigger endothelium-dependent relaxations are the adenine nucleotides and serotonin. The ability of the endothelium to prevent platelet-induced vasospasm is augmented after chronic intake of cod liver oil, but is reduced after previous intimal injury.
Vanhoutte
P M
PM
Department of Physiology and Biophysics, Mayo Clinic, Rochester, Minnesota 55905.
D000227:Adenine Nucleotides / Q000502:physiology; D000818:Animals; D001792:Blood Platelets / Q000502:physiology*; D001808:Blood Vessels / Q000502:physiology*; D003329:Coronary Vasospasm / Q000209:etiology; D004730:Endothelium, Vascular / Q000502:physiology*; D006801:Humans; D010972:Platelet Activating Factor / Q000502:physiology; D010974:Platelet Aggregation; D013931:Thromboxanes / Q000502:physiology; D014661:Vasoconstriction
D000227:Adenine Nucleotides; D010972:Platelet Activating Factor; D013931:Thromboxanes