Early effects of alloxan on rat submandibular gland.

Early effects of alloxan on structure and function of rat submandibular gland were investigated by light and electron microscopy, X-ray microanalysis, and by analysis of secreted saliva. Alloxan induced, already within 3 h, intracellular accumulation of mucus, as also evidenced by an increase in the cellular calcium concentration. In addition, 3 to 6 h after injection of alloxan, the granular duct cells were found to be vacuolated, which could suggest a cytotoxic effect of alloxan on this cell type. Alloxan did not significantly affect the flow rate of submandibular saliva after pilocarpine stimulation, and also did not significantly alter the concentrations of sodium, potassium, calcium and protein in the final saliva. The effects of alloxan on the acinar cells of the rat submandibular gland and the absence of effects on fluid secretion by this gland are in accordance with a direct or indirect inhibition of the cAMP system.