Saad Wilson A, Guarda I F M S, Camargo L A A, Santos T A F B, Guarda R S, Saad Willian A, Simões S, Rodrigues J Antunes
Odontologia UNITAU, Universidade Estadual Paulista, Araraquara, SP, Brasil.
Braz J Med Biol Res. 2003 Jul;36(7):897-905. doi: 10.1590/s0100-879x2003000700010. Epub 2003 Jun 26.
We investigated the effect of L-NAME, a nitric oxide (NO) inhibitor and sodium nitroprusside (SNP), an NO-donating agent, on pilocarpine-induced alterations in salivary flow, mean arterial blood pressure (MAP) and heart rate (HR) in rats. Male Holtzman rats (250-300 g) were implanted with a stainless steel cannula directly into the median preoptic nucleus (MnPO). Pilocarpine (10, 20, 40, 80, 160 g) injected into the MnPO induced an increase in salivary secretion (P<0.01). Pilocarpine (1, 2, 4, 8, 16 mg/kg) ip also increased salivary secretion (P<0.01). Injection of L-NAME (40 g) into the MnPO prior to pilocarpine (10, 20, 40, 80, 160 g) injected into the MnPO or ip (1, 2, 4, 8, 16 mg/kg) increased salivary secretion (P<0.01). SNP (30 g) injected into the MnPO or ip prior to pilocarpine attenuated salivary secretion (P<0.01). Pilocarpine (40 g) injection into the MnPO increased MAP and decreased HR (P<0.01). Pilocarpine (4 mg/kg body weight) ip produced a decrease in MAP and an increase in HR (P<0.01). Injection of L-NAME (40 g) into the MnPO prior to pilocarpine potentiated the increase in MAP and reduced HR (P<0.01). SNP (30 g) injected into the MnPO prior to pilocarpine attenuated (100%) the effect of pilocarpine on MAP, with no effect on HR. Administration of L-NAME (40 g) into the MnPO potentiated the effect of pilocarpine injected ip. SNP (30 g) injected into the MnPO attenuated the effect of ip pilocarpine on MAP and HR. The present study suggests that in the rat MnPO 1) NO is important for the effects of pilocarpine on salivary flow, and 2) pilocarpine interferes with blood pressure and HR (side effects of pilocarpine), that is attenuated by NO.
我们研究了一氧化氮（NO）抑制剂L-精氨酸甲酯（L-NAME）和NO供体硝普钠（SNP）对毛果芸香碱诱导的大鼠唾液分泌、平均动脉血压（MAP）和心率（HR）变化的影响。将雄性霍尔茨曼大鼠（250 - 300克）的不锈钢套管直接植入视前正中核（MnPO）。向MnPO注射毛果芸香碱（10、20、40、80、160微克）可使唾液分泌增加（P<0.01）。腹腔注射毛果芸香碱（1、2、4、8、16毫克/千克）也可增加唾液分泌（P<0.01）。在向MnPO注射毛果芸香碱（10、20、40、80、160微克）或腹腔注射（1、2、4、8、16毫克/千克）之前，向MnPO注射L-NAME（40微克）可增加唾液分泌（P<0.01）。在毛果芸香碱之前向MnPO或腹腔注射SNP（30微克）可减弱唾液分泌（P<0.01）。向MnPO注射毛果芸香碱（40微克）可使MAP升高，HR降低（P<0.01）。腹腔注射毛果芸香碱（4毫克/千克体重）可使MAP降低，HR升高（P<0.01）。在毛果芸香碱之前向MnPO注射L-NAME（40微克）可增强MAP的升高并降低HR（P<0.01）。在毛果芸香碱之前向MnPO注射SNP（30微克）可减弱（100%）毛果芸香碱对MAP的作用，对HR无影响。向MnPO注射L-NAME（40微克）可增强腹腔注射毛果芸香碱的作用。向MnPO注射SNP（30微克）可减弱腹腔注射毛果芸香碱对MAP和HR的作用。本研究表明，在大鼠MnPO中，1）NO对毛果芸香碱的唾液分泌作用很重要，2）毛果芸香碱会干扰血压和HR（毛果芸香碱的副作用），而NO可减弱这种干扰。
