A study on histamine and histaminase activity in nasal allergy (author's transl)

Abstract

Studies on histamine release from target cells of reaginic antibodies were markedly advanced by discoveries of IgE and cyclic AMP, while histamine metabolism in allergic patients was little known. The inactivation of histamine released from mast cells, basophils and platelets is very important in allergic patients with histamine hypersensitivity. Bernauer and coworkers (1964) discovered that heparin liberate histaminase in guinea pig. It is suggested that histaminase might be liberated by heparin from target cells on allergic reaction. In present study histamine contents of nasal washings, nasal mucous membranes and plasma from allergic and non-allergic subjects were measured using fluorometric assay. Plasma histamine level was elevated in allergic patients and more rised (56.6%±23.3 SD) within 5 minutes after nasal provocation by allergen. The histamine content of nasal washings was less in allergic (0.069 μg/total volume±0.032 SD) than non-allergic subjects (0.673μg/total volume±0.470 SD). The histamine content of nasal washings increased after nasal provocation by allergen and the same result was obtained by acetylcholine in allergic and vidian neurectomized patients. No increase in histamine contents was noted in nasal washings and plasma from healthy subjects following nasal provocation. The histamine contents of nasal mucous membranes were less in most allergic (0.218μg/mg protein ±0.135 SD) than non-allergic (0.397μg/mg protein ±0.176 SD), but high histamine contents were observed in some allergic patients. Histaminase (diamine oxidase) activity in nasal mucous membrane and plasma histaminase activity (PHNA) were determined by o-dianisidine-peroxidase method, which was rapid, sensitive and simple as described by Aarsen & Kemp in 1964. The histaminase activity in nasal mucous membrane was increased in allergic patients (0.031mμM/mg protein/min±0.022SD). PHNA was increased in 113 allergic and 20 asthmatic patients (2.49mμM/ml/min±1.17SD) and reduced to normal level (1.50mμM/ml/min ± 0.07 SD) by hyposensitisation or Histaglobin injections. PHNA was increased after nasal provocation by allergen. The level of PHNA and scores of nasal symptom such as sneezing and watery rhinorrhea were correlated (p<0.01). These results suggested that the histamine metabolism was enhanced in allergic patients.