Adaptive increase in mammalian histidine decarboxylase activity in response to nonspecific stress

Abstract

Adaptive increase in histidine decarboxylase activity has been found to occur in all of the three species tested after a variety of stressful stimuli in rat skin following injection of polymyxin B, in mouse skin after burns, in lungs of mice injected with pertussis vaccine and in the skin of guinea pigs during the development of the tuberculin reaction. Mammalian histidine decarboxylase is one of the few enzymes which have been shown to increase in response to nonspecific stress; furthermore the conditions induced by these stressful stimuli have ‘histaminic’ implications. After a discussion of fallacies in earlier studies on the evaluation of the role of histamine, it is concluded that adaptive increase in histidine decarboxylase, attended by slow but increasing formation of histamine, must be seriously considered as an important causative mechanism in slowly developing inflammation.