用离体犬脑血管（基底动脉）环标本，观察γ－氨基丁酸（ＧＡＢＡ）对几种不同激动剂所致最大收缩反应的舒张作用。苯福林（ＰＥ）１０μｍｏｌ·Ｌ－１，５－羟色胺（５－ＨＴ）１０μｍｏｌ·Ｌ－１以及２５ｍｍｏｌ·Ｌ－１的ＫＣｌ均可使脑血管静息张力增加，ＧＡＢＡ５０μｍｏｌ·Ｌ－１对以上几种激动剂所致的收缩反应均有舒张作用。对较高浓度的ＫＣＩ（４５ｍｍｏｌ·Ｌ－１）所致的收缩无影响，但对由冷刺激（未预热的营养液，２８℃）引起的收缩反应有明显的舒张作用。 Using isolated canine cerebral artery (basilar artery) loop specimens, the effect of γ-aminobutyric acid (GABA) on the maximal contractile response induced by several different agonists was observed. Phenylephrine (PE) 10μmol·L-1, 5-HT 10μmol·L-1 and 25mmol·L-1 KCl both increased the resting blood pressure of cerebrovascular, GABA50μmol·L-1 above Contractile responses induced by several agonists have a relaxing effect. It had no effect on contractility induced by higher concentration of KCI (45 mmol·L-1), but had a significant relaxation effect on the contractile response induced by cold stimulation (28 ° C).