Muscarinic cholinergic receptors (MR3) in saliva of patients with oral lichen planus

Oral lichen planus (OLP) is a relatively common, chronic, and inflammatory mucocutaneous disease. Xerostomia is also a common complaint of most OLP patients. Considering the significant role of M3 muscarinic receptors (M3R) in secretion of saliva, this study sought to compare the level of this receptor in saliva between OLP patients and healthy controls. Forty OLP patients and 40 healthy controls filled out two questionnaires regarding xerostomia to assess its degree of severity. Unstimulated and stimulated salivary samples were obtained of both groups and the stimulated and unstimulated salivary flow rates were calculated. Salivary level of M3 muscarinic receptors was measured using the ELISA kit. Data were analyzed and compared using unpaired student's t test. P < 0.05 was considered significant. Stimulated and unstimulated salivary flow rates and M3 muscarinic receptors levels were significantly lower but degree of xerostomia was significantly higher in OLP patients compared to healthy controls. Salivary M3 muscarinic receptor seems to be low in the patients with OLP and these patients suffer from xerostomia and reduced salivary flow rate.