The effect of clonidine treatment on the salivary glands of the rat. Results of biochemical and histological investigations.

The side-effects of clonidine, dryness of the mouth and parotid pain, as displayed by this clinically frequently used antihypertensive drug prompted us to investigate its effect on the salivary glands of the rat. After daily intraperitoneal injections for 3 weeks clonidine decreased the specific amylase content of the submaxillary glands caused by fall of activity in 2 of the 4 isoamylases. On the other hand, both activity of alpha-amylase and its isoenzyme pattern remained unchanged in the parotid glands as did their histological and histochemical appearance. The lymph nodes situated in front of the submaxillary glands, however, were considerably affected showing large abscesses. In the adjacent glandular parenchyma, round cell infiltrations and, occasionally, acinic cell necroses were observed.