Interaction of the agonist and antagonist of dopamine receptors on the saliva secretion in the ra

The bilateral relationship between Ventro Medial Nucleus and dopaminergic system may play an important role in the secretion of the gastrointestinal exocrine glands, nutritional behaviors and habits. The aim of this study was to investigate the role of dopaminergic receptors in regulation of the exocrine glands and to find out whether the change in saliva secretion is the primary effects of central nervous system or there are subsequences of taking food, lick, swallowing and digestion in the mouth. Ninety rats were stereotaxically implanted under urethane anesthesia. The rats were divided into 9 groups: one control group, one fasted control group, two sham groups given surgery and surgery plus medicine solvents, one SCH23390 group, one bromocriptine group, one mixed group: SCH23390 along with bromocriptine, one pilocarpine and a mixed group: bromocriptine along with pilocarpine. In this study, saliva secretion was gathered from submandibular glands by cannulas and measures then volume of secretion by using SPSS program the groups were compared (Test Anova). The saliva secretion was not significantly different between all groups except SCH23390 group, pilocarpine, and both mixed groups which showed significant differences in the saliva secretion. This study showed that SCH23390 (7.5 μg) could increase saliva secretion. Bromocriptine could not affect saliva secretion. Bromocriptine along with pilocarpine significantly decreased saliva secretion. However, this agonist together with SCH23390 significantly increased saliva secretion. So the dopaminergic system of the Ventro Medial Nucleus has a considerable effect on the secretion of the exocrine glands in the digestive system.