Nicotinamide prevents lymphocytic infiltration in submandibular glands but not the appearance of anti-salivary duct antibodies in non-obese diabetic (NOD) mice.

Previously we have shown that nicotinamide prevents spontaneously occurring diabetes associated with insulitis in non-obese diabetic (NOD) mice. In this study we injected nicotinamide (0.5 mg/g) or saline (0.01 ml/g) into female NOD mice daily during a period between 4 and 16 weeks of age. At the end of the treatment, periductal and perivascular lymphocytic infiltration in submandibular glands was observed in 91% of saline-injected control mice and 36% of nicotinamide-injected mice (P less than 0.01). No significant difference was observed in the prevalence of anti-salivary duct antibodies or antinuclear antibodies between the nicotinamide group and the saline group. Nicotinamide may alter cell-mediated, but not humoral, immunity to salivary gland cells, resulting in the prevention of submandibulitis.