γ-氨基丁酸对离体犬脑血管的作用

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。

EFFECTS OF γ-AMINOBUTYRIC AND ON ISOLATED DOG CEREBRAL ARTERIES

The present experiments were designed to investigate the effects of γ-aminobutyricacid(GABA) on isolated dog cerebral arteries(basilar arter). on addition of agonists phenylephrine10μmol·L^-1,5-HT 10μmol·L^-1, or KCl 25 mmol·L^-1, the isometric tension of the contrac-tion increased 0,51±0.18g,0.33±0.12 g and 0.57±0.16g. After GABA at 50μmol·L^-1,the contraction was shown to decrease 0.27±0.15g,0.19±0.07g and 0.17±0.06g,themaximal relaxation were 45.49%±26.4%, 58.60%±12.96%and 27.75%±15.78%,respectively. But it showed no effect on the contraction induced by high concentration of KCl (45mmol·L^-1).GABA also showed a potent relaxation on the contraction induced by cold Krebssolution(T 28±0.5℃). The finding suggest that GABA can inhibit the muscle tone induced byvarious agonists and cooling in isolated dog basilar artery.