Histamine H-1 binding site on human polymorphonuclear leukocytes
S Wescott, M Kaliner
Neutrophilic polymorphonuclear leukocytes (PMN) infiltrate the sites of allergic reactions and may respond to histamine, one of the major mediators of allergy. In order to characterize histamine interactions with PMN, the binding of [3H]pyrilamine was studied. Human PMNs bind [3H]pyrilamine in a specific, saturable, and reversible fashion and demonstrate specificity (H-1 antagonists greater than histamine greater than H-2 antagonists) for the competitive binding agents studied. Human PMNs have a homogeneous population of H-1 receptors of moderate affinity (Kd = 52 nM) in large number (265 X 10(3)/cell) which do not demonstrate cooperativity. Thus PMNs attracted to sites of allergic inflammation have H-1 binding sites which may respond to histamine stimulation.
Allergy and asthma are inflammatory disorders that are triggered by the activation of an allergen-specific regulatory t cell. These t cells become activated when allergens are recognized by allergen-presenting cells. Here is the latest research on allergy and asthma.