Effects of nicotine on salivary amylase secretion from rabbit parotid gland

1. The effects of nicotine on amylase secretion induced by auriculo-temporal nerve stimulation were studied.2. Nicotine caused a transient increase in secretion as well as flow rate of amylase.3. No difference in nicotine action was found between acute sympathetic decentralization of the gland and acute denervation.4. The increase in amylase secretion due to nicotine was not inhibited by phenoxybenzamine, bretylium and chronic denervation, but was prevented by hexamethonium, propranolol and adrenalectomy.5. The increase in flow rate due to nicotine was not inhibited by propranolol, chronic denervation and adrenalectomy, but was prevented by hexamethonium, phenoxybenzamine and bretylium.6. These results show that the action of nicotine in increasing amylase secretion is neither a direct action on the ganglion nor on the nerve terminal of the cervical sympathetic nerve, but is an indirect action of catecholamines released from the adrenal medulla on the post-junctional receptors.7. The study also suggests that the initial acceleration of salivary flow due to nicotine is characterized by a mechanism different from that of amylase secretion.