[Histochemical experiments on the action of clenbuterol on tracheal mucosa (author's transl)].

The effect of 4-amino-alpha-[(tert.-butylamino) methyl]-3,5-dichlorobenzyl alcohol hydrochloride (clenbuterol, Spiropent) on the tracheal mucosa was examined in 56 guinea pigs after i.p. administration during 5, 12 and 28 days, respectively. The alkaline phosphatases showed a minimum increase only in long-term tests. This increase concerned mainly the capillaries. It can be interpreted as a sign of enhanced transport processes. After administration of clenbuterol the total acid phosphatase in the mucosal epithelium rose. After a transient apical secretion of enzymes--together with consumption of enzymes at increased secretion--apparently more of new enzymes are produced. As a lysosomal enzyme the glucosaminidase showed also a similar reaction as did the acid phosphatase, while non-specific esterases increased only minimally or moderately. The effect of clenbuterol decreased the number of stainable goblet cells of the mucosa. It came to a secretory evacuation as a result of the secretolytic effect of the test substance in secretory evacuation. At the same time, the part of acid mucus components containing neuraminic acid rose so much that a qualitative change in the sense of the mucus components shifting in the direction to neuraminidasesensitive acid glycosaminoglycanes could be demonstrated.