Preckel M P, Leftheriotis G, Ferber C, Degoute C S, Banssillon V, Saumet J L
Service d'Anesthésie-Réanimation CHU Lyon-Sud, Pierre-Bénite, France.
Int J Microcirc Clin Exp. 1996 Nov-Dec;16(6):277-83. doi: 10.1159/000179186.
The role of nitric oxide (NO) in cerebral autoregulation is controversial. The purpose of this study was to compare the effects on the lower limit of the cortical cerebral autoregulation of the inhibition of NO synthesis by N omega-nitro-L-arginine (L-NNA) infusion to saline and phenylephrine in pentobarbital-anaesthetized rats. Variations of the cortical cerebral blood flow (CBF), the cortical cerebrovascular resistances, the mean arterial pressure and the lower limit of cerebral autoregulation were compared in three groups: a group pretreated with L-NNA (n = 8), a group pretreated with saline (n = 8) and a group pretreated with phenylephrine (n = 5). The laser-Doppler flowmetry continuously measured CBF. Controlled haemorrhage was performed after the intravenous infusion of L-NNA, saline, or phenylephrine. The lower limit of cerebral autoregulation of each rat was computed by the least-squares method. The lower limit of cerebral autoregulation was significantly higher after L-NNA infusion (74 +/- 5 mm Hg) than after saline (43 +/- 3 mm Hg; p < 0.01) or phenylephrine infusions (52 +/- 5 mm Hg; p < 0.05). In conclusion, the role of NO on the cerebral autoregulation has been controversial; our results confirm the hypothesis that NO exerts a significant role in maintaining the lower limit of cerebral autoregulation in pentobarbital-anaesthetized rats.
一氧化氮（NO）在脑自动调节中的作用存在争议。本研究的目的是比较在戊巴比妥麻醉的大鼠中，通过输注Nω-硝基-L-精氨酸（L-NNA）抑制NO合成与输注生理盐水和去氧肾上腺素对皮质脑自动调节下限的影响。比较了三组的皮质脑血流量（CBF）、皮质脑血管阻力、平均动脉压和脑自动调节下限的变化：一组预先用L-NNA处理（n = 8），一组预先用生理盐水处理（n = 8），一组预先用去氧肾上腺素处理（n = 5）。激光多普勒血流仪连续测量CBF。在静脉输注L-NNA、生理盐水或去氧肾上腺素后进行控制性出血。通过最小二乘法计算每只大鼠的脑自动调节下限。输注L-NNA后（74±5 mmHg）脑自动调节下限显著高于输注生理盐水后（43±3 mmHg；p<0.01）或输注去氧肾上腺素后（52±5 mmHg；p<0.05）。总之，NO在脑自动调节中的作用一直存在争议；我们的结果证实了以下假设：在戊巴比妥麻醉的大鼠中，NO在维持脑自动调节下限方面发挥着重要作用。
