Wang Y X, Zhou T, Pang C C
Department of Pharmacology and Therapeutics, Faculty of Medicine, University of British Columbia, Vancouver, Canada.
Eur J Pharmacol. 1991 Jul 23;200(1):77-81. doi: 10.1016/0014-2999(91)90668-g.
The effects of NG-nitro-L-arginine (L-NNA) and NG-nitro-D-arginine (D-NNA) on mean arterial pressure (MAP) were studied in conscious, unrestrained rats. I.v. bolus of either L-NNA (1-64 mg/kg) or D-NNA (2-64 mg/kg) dose dependently increased MAP to similar maximum values of 55 +/- 7 and 52 +/- 4 mm Hg and with ED50 values of 4.0 +/- 0.9 and 8.9 +/- 1.2 mg/kg (P less than 0.05), respectively. The time course of the MAP response to a single dose (32 mg/kg i.v. bolus) of L-NNA and D-NNA were also obtained. The pressor effects of L-NNA and D-NNA each lasted greater than 2 h with the rise phase t 1/2 of 5 and 27 min (P less than 0.05), respectively. I.v. infusions (10 mg/kg per min) of L-arginine (L-Arg) and D-arginine (D-Arg) did not alter the pressor response to noradrenaline nor angiotensin II. L-Arg but not D-Arg attenuated the pressor responses to both L-NNA and D-NNA. Therefore, both L-NNA and D-NNA are efficacious and long-lasting pressor agents; the pressor effects of both can be antagonized by L-Arg but not D-Arg. Our results suggest that the pressor effects of both L-NNA and D-NNA involve the L-Arg/nitric oxide pathway.
在清醒、未束缚的大鼠中研究了NG-硝基-L-精氨酸（L-NNA）和NG-硝基-D-精氨酸（D-NNA）对平均动脉压（MAP）的影响。静脉注射单次推注L-NNA（1-64mg/kg）或D-NNA（2-64mg/kg）剂量依赖性地升高MAP至相似的最大值，分别为55±7和52±4mmHg，ED50值分别为4.0±0.9和8.9±1.2mg/kg（P<0.05）。还获得了对单次剂量（32mg/kg静脉推注）L-NNA和D-NNA的MAP反应的时间过程。L-NNA和D-NNA的升压作用各自持续超过2小时，上升期t1/2分别为5和27分钟（P<0.05）。静脉输注（10mg/kg每分钟）L-精氨酸（L-Arg）和D-精氨酸（D-Arg）不改变对去甲肾上腺素和血管紧张素II的升压反应。L-Arg而非D-Arg减弱了对L-NNA和D-NNA两者的升压反应。因此，L-NNA和D-NNA都是有效的长效升压剂；两者的升压作用都可被L-Arg而非D-Arg拮抗。我们的结果表明，L-NNA和D-NNA的升压作用都涉及L-Arg/一氧化氮途径。
