Abdollahi M, Dehpour A, Shafayee F
Department of Toxicology and Pharmacology, Faculty of Pharmacy, Tehran University of Medical Sciences, Iran.
Pharmacol Toxicol. 2000 Nov;87(5):198-203. doi: 10.1034/j.1600-0773.2000.d01-74.x.
The effects of lead acetate, L-arginine (nitric oxide precursor) and L-NAME (nitric oxide synthesis inhibitor) on rat submandibular secretory function were studied. Pure submandibular saliva was collected intraorally from anaesthetized rats by a micro polyethylene cannula using pilocarpine as secretagogue. Treatment for twenty-eight days with three doses of lead acetate (0.01%, 0.04%, 0.05% w/v) in drinking water caused significant alterations on salivary function. Salivary flow rate was decreased by lead at all doses used. The total protein concentration and amylase activity of saliva were both decreased by lead (0.04% and 0.05%). All doses of lead decreased saliva calcium concentrations. Two weeks' treatment of rats by L-arginine (2.25% w/v) and L-NAME (0.7% w/v) in drinking water also affected the saliva secretory function. L-Arginine caused increase in submandibular gland weight. The saliva flow rate was reduced by L-NAME. The total protein concentration of saliva was increased by L-arginine and decreased by L-NAME. Amylase activity was reduced by L-arginine treatment. Calcium concentration was reduced by L-arginine and increased by L-NAME. Concurrent L-arginine treatment with lead acetate recovered lead-induced reduction of flow rate but L-NAME potentiated it. Concurrent therapy of lead and L-NAME resulted in greater reduction of protein concentration when compared to that of lead. L-Arginine showed a preventive effect on lead-induced decrease of protein concentration. Both L-arginine and L-NAME prevented lead-induced reduction in calcium concentration. It is concluded that nitric oxide plays a role in salivary gland function. Also lead acetate inhibitory effect on submandibular function is somewhat diminished by L-arginine and partially increased by L-NAME. It seems that lead acetate interacts with nitric oxide modulatory role in salivary gland.
研究了醋酸铅、L-精氨酸（一氧化氮前体）和L-NAME（一氧化氮合成抑制剂）对大鼠颌下腺分泌功能的影响。使用毛果芸香碱作为促分泌剂，通过微型聚乙烯插管从麻醉大鼠口腔内收集纯颌下腺唾液。用三种剂量（0.01%、0.04%、0.05% w/v）的醋酸铅在饮用水中处理大鼠28天，导致唾液功能发生显著改变。所有使用剂量的铅均降低唾液流速。铅（0.04%和0.05%）使唾液中的总蛋白浓度和淀粉酶活性均降低。所有剂量的铅均降低唾液钙浓度。在饮用水中用L-精氨酸（2.25% w/v）和L-NAME（0.7% w/v）处理大鼠两周也影响唾液分泌功能。L-精氨酸导致颌下腺重量增加。L-NAME降低唾液流速。L-精氨酸使唾液总蛋白浓度升高，L-NAME使其降低。L-精氨酸处理降低淀粉酶活性。L-精氨酸降低钙浓度，L-NAME使其升高。L-精氨酸与醋酸铅同时处理可恢复铅诱导的流速降低，但L-NAME使其增强。与单独使用铅相比，铅与L-NAME联合治疗导致蛋白浓度降低幅度更大。L-精氨酸对铅诱导的蛋白浓度降低具有预防作用。L-精氨酸和L-NAME均能预防铅诱导的钙浓度降低。结论是一氧化氮在唾液腺功能中起作用。此外，L-精氨酸可部分减轻醋酸铅对颌下腺功能的抑制作用，而L-NAME则使其部分增强。似乎醋酸铅与一氧化氮在唾液腺中的调节作用相互作用。
