Specific receptors of platelet-activating factor, receptor heterogeneity, and signal transduction mechanisms.
Platelet-activating factor (PAF) exerts its actions through the activation of specific PAF receptors found in a variety of cells and tissues. The signal transduction process induced by PAF appears to be modulated by guanine nucleotide-regulatory proteins (G-proteins) in both rabbit and human platelets and also in human polymorphonuclear leukocytes (PMNs). The PAF receptor, the G-protein coupled to the receptor, and the signal transduction mechanisms in human platelets are different from those in human PMNs. The PAF receptor in human PMNs may also be different from that in human eosinophils. The existence of receptor heterogeneity in guinea pig eosinophils is also proposed. Thus PAF receptor subtypes do exist. Further investigations are required to understand the role of each individual PAF receptor subtype.
Hwang
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SB
Merck Sharp and Dohme Research Laboratories, Department of Biochemical Regulation, Rahway, NJ 07065.
D000818:Animals; D001792:Blood Platelets / Q000502:physiology; D004804:Eosinophils / Q000502:physiology; D019204:GTP-Binding Proteins / Q000502:physiology; D006801:Humans; D009504:Neutrophils / Q000502:physiology; D010972:Platelet Activating Factor / Q000502:physiology*; D010980:Platelet Membrane Glycoproteins; D011956:Receptors, Cell Surface / Q000037:antagonists & inhibitors / Q000145:classification / Q000502:physiology*; D043562:Receptors, G-Protein-Coupled; D015398:Signal Transduction / Q000502:physiology
D010972:Platelet Activating Factor; D010980:Platelet Membrane Glycoproteins; D011956:Receptors, Cell Surface; D043562:Receptors, G-Protein-Coupled; C039351:platelet activating factor receptor; D019204:GTP-Binding Proteins