The changes of activities of hexokinase, lactate dehydrogenase and glucose-6-dehydrogenase were examined in the submaxillary gland of streptozotocin-induced diabetic rats and in that treated with insulin in vitro. Atrophy of the submaxillary gland and the decreases in activities of those enzymes were observed in the diabetic rats. On the other hand, activities of those enzymes were increased by insulin. It was discussed that findings may be related to the oral physiological dysfunction and several symptoms caused in the oral cavity in patients with diabetes mellitus.
It was demonstrated that the secretion of parotid saliva is evoked by the administration of dopamine into the rabbit. The response was dose-dependent in the secretory rate. In addition, the dopamine-evoked parotid saliva was not inhibited by rising the dose of priscol or propranolol. Whereas, the dopamine-evoked parotid saliva was nearly blocked by chlorpromazine or haloperidol. From the above mentioned results, we suggested that the specific dopamine receptor may be present in the rabbit parotid gland.