A fluorescent histochemical investigation of the rat submandibular gland after ligation of the excretory duct and isoproterenol treatment

Fluorescent histochemical investigations were carried out on the adrenergic terminal plexus in the salivary gland of the rat 24 hours, 72 hours, and 14 days after ligation of the main excretory duct and the concomitant administration of isoproterenol (IPR, 60 mg/kg body weight subcutaneously). The atrophy of the salivary gland occurring after ligation was also present after the concomitant administration of IPR which induces amylase secretion and DNA synthesis in intact salivary glands. The adrenergic fibres in the atrophic gland exhibited an intensive fluorescence of the adrenergic terminal plexus after IPR treatment. Thus the presynaptic elements remain intact, although the acini are atrophic, and the reason for the absence of the stimulus response probably lies in the effector cells.