Kawakami M, Kodama N, Toda N
Department of Pharmacology, Shiga University of Medical Sciences, Ohtsu, Japan.
Neurosurgery. 1991 Jan;28(1):33-9; discussion 39-40. doi: 10.1097/00006123-199101000-00006.
Oxyhemoglobin (Oxy-Hb) produced a concentration-dependent contraction of monkey, dog, and bovine cerebral artery strips. Treatment of Oxy-Hb with ascorbic acid suppressed the ability of Oxy-Hb to contract the arteries, especially in the monkey arteries. The ability of intracisternally applied Oxy-Hb to constrict the basilar artery in anesthetized dogs was diminished when Oxy-Hb was treated previously with ascorbic acid (AsA-Hb). The contraction caused by Oxy-Hb was suppressed by treatment with indomethacin and aspirin in isolated bovine cerebral arteries. Endothelium-dependent relaxations elicited by substance P and relaxations induced by stimulation of the vasodilator nerves with nicotine were suppressed by treatment with Oxy-Hb and AsA-Hb; however, the inhibitory effect of AsA-Hb was markedly less. Oxy-Hb attenuated nitroglycerin-induced relaxations in a dose-dependent fashion, whereas AsA-Hb in concentrations up to 1.6 x 10(-5) M did not significantly influence the relaxations. It is concluded that incubation of Oxy-Hb with ascorbic acid alters markedly the biological activity of Oxy-Hb; the vasoconstrictor activity is suppressed, and the ability to diminish vasodilator actions is minimized. These findings provide a rationale for the use of ascorbic acid in cisternal irrigation to prevent the development of cerebral vasospasm after a subarachnoid hemorrhage.
氧合血红蛋白（Oxy-Hb）可使猴、犬和牛的脑动脉条产生浓度依赖性收缩。用抗坏血酸处理Oxy-Hb可抑制其使动脉收缩的能力，在猴动脉中尤为明显。当预先用抗坏血酸处理Oxy-Hb（AsA-Hb）后，脑池内注入Oxy-Hb使麻醉犬基底动脉收缩的能力减弱。在离体牛脑动脉中，吲哚美辛和阿司匹林处理可抑制Oxy-Hb引起的收缩。P物质引起的内皮依赖性舒张以及尼古丁刺激血管舒张神经诱导的舒张，均受到Oxy-Hb和AsA-Hb处理的抑制；然而，AsA-Hb的抑制作用明显较小。Oxy-Hb以剂量依赖性方式减弱硝酸甘油诱导的舒张，而浓度高达1.6×10⁻⁵ M的AsA-Hb对舒张无明显影响。结论是，Oxy-Hb与抗坏血酸孵育可显著改变Oxy-Hb的生物学活性；血管收缩活性受到抑制，减弱血管舒张作用的能力降至最低。这些发现为在脑池冲洗中使用抗坏血酸预防蛛网膜下腔出血后脑血管痉挛的发生提供了理论依据。
