INDUCTION OF TYPE-2 CYSTATIN IN RAT SUBMANDIBULAR GLANDS BY SYSTEMICALLY ADMINISTERED AGENTS

An inducible type 2 cystatin has earlier been characterized in submand ibular glands and kidneys of rats treated with isoproterenol, as well as in kidneys of rats with experimental renal disease. The purpose now was to determine whether giving agents that have systemic toxicity co uld also be associated with induction of cystatin in rat salivary glan ds. Female Wistar rats (200-250 g) were given isoproterenol, cyclocyti dine, potassium dichromate or turpentine oil. After autopsy, the organ s were sectioned, fixed in 10% formalin, and processed routinely. Para ffin sections were processed for both the peroxidase-antiperoxidase an d the avidin-biotin-alkaline phosphatase immunocytochemical methods. T he submandibular glands of rats given cyclocytidine had generalized, s trong staining of acinar cells, as well as occasional weak staining wi thin granular convoluted tubules. Animals given either potassium dichr omate or turpentine oil exhibited moderate staining for cystatin in su bmandibular acini. Rats given isoproterenol as a positive control exhi bited strong acinar staining throughout the submandibular gland, while the glands of untreated rats were unreactive. Inducible type 2 cystat in could not be detected in the parotid or sublingual glands, or in tr achea, lung, stomach, small intestine, large intestine, spleen, liver and pancreas, after treatment with any of the systemic agents evaluate d. The results indicate that elaboration of type 2 cystatin can be ind uced by a variety of systemically administered agents other than isopr oterenol, and suggest that elaboration of type 2 cystatin may represen t a more generalized response to tissue injury.