Alterations in nitric oxide synthase activity and expression in submandibular glands of NOD mice.

The non-obese diabetic (NOD) mouse model of autoimmune sialadenitis offers the possibility of studying the L-arginine/nitric oxide signaling pathway in salivary glands in basal and neurotransmitter-stimulated conditions and, thus, of analyzing the neural control of the secretory process in the target organ. The purpose of this study was to explore putative alterations in the activity and expression of nitric oxide synthase (NOS) in submandibular glands of NOD mice in relation to parotid glands and unrelated tissues. Here we report that NOD mice with incipient signs of secretory dysfunction presented a marked decrease in basal and vasoactive intestinal peptide (VIP)-stimulated NOS activity and a differential expression of NOS I in submandibular glands compared to control BALB/c mice. Similar alterations in NOS I were found in parotid glands but not in brain or spleen of NOD mice. No differences between NOD and controls appeared in NOS II and NOS III expression in any of the tissues studied.