Pulmonary endocrine cells in pulmonary arterial disease.

Pulmonary endocrine cells containing bombesin or calcitonin have been identified in human lungs by the peroxidase-antiperoxidase method. The numbers of such cells were greatly increased in patients with plexogenic pulmonary arteriopathy whether that condition was associated with primary pulmonary hypertension or with pulmonary hypertension from intracardiac shunts. The numbers of endocrine cells tended to be increased, but to a lesser extent in patients with pulmonary hypertension and medial hypertrophy of the muscular pulmonary arteries in the absence of plexogenic arteriopathy. Increased numbers of endocrine cells comprised both greater numbers of solitary cells and a pronounced clustering, often of a disorganized nature.