烟碱和槟榔碱对大鼠颌下腺肌醇含量的影响

急性实验中，间隔5 min反复ip N受体激动剂烟碱0.5, 1.0, 1.0, 2.0, 2.0 mg·kg^-1可显著提高大鼠颌下腺中肌醇含量，并为N受体拮抗剂美加明1.0 mg·kg^-1对抗，为肌醇磷酸酶抑制剂氯化锂69.4 mg·kg^-1 ip翻转；一次性ip M受体激动剂槟榔碱200 mg·kg^-1也可显著提高颌下腺肌醇含量，并为M受体拮抗剂阿托品2.0 mg·kg^-1对抗；反复注射烟碱后，再ip不影响肌醇含量的槟榔碱50 mg·kg^-1，两者产生协同效应，进一步提高肌醇含量. 慢性实验中，每日2次sc烟碱2.0-5.0 mg·kg^-1或槟榔碱2.0-10.0 mg·kg^-1 14 d后，均可使大鼠颌下腺中肌醇含量显著降低.

Effects of nicotine and arecoline on inositol levels of rat submandibular glands

In the acute experiments, the inositol levels of rat submandibular glands were increased by repeating five doses of nicotine 0.5, 1.0, 1.0, 2.0 and 2.0 mg·kg^-1 ip at 5 min intervals, which was prevented by nicotinic antagonist mecamylanine (1.0 mg·kg^-1 ip), and was inverted by lithium chloride (69.4 mg·kg^-1 ip), an inositol phosphatase inhibitor. Muscarinic agonist arecoline 200 mg·kg^-1 ip also increased the inositol levels, which was prevented by muscarinic antagonist atropine (2.0 mg·kg^-1 ip). The synergism on the increases in inositol levels of rat submandibular glands was observed between the five doses of nicotine and arecoline 50 mg·kg^-1 ip. But in the chronic experiments, the inositol levels were decreased by nicotine 2.0-5.0 mg·kg^-1 or arecoline 2.0-10.0 mg·kg^-1 sc twice a day for 14 d.