Serum histamine level in exercise-induced bronchospasm.
The changes in serum histamine levels were studied in 12 asthmatic patients: 6 patients gave positive responses and 6 gave negative responses to physical exercise. The serum histamine was determined fluorometrically, and the specific airway conductance was used as the spirometric criteria. The serum histamine levels were elevated in the patients who gave positive responses to exercise. In the negative responders to exercise, the serum histamine levels did not alter significantly. The changes in specific airway conductance and serum histamine levels were not in parallel during the entire reaction, suggesting the intervention of other immediate type hypersensitivity mediators in exercise-induced bronchospasm. The authors proved the role of histamine in the pathophysiology of exercise induced bronchospasm.