[Effects of gamma-aminobutyric acid on isolated dog cerebral arteries].
The present experiments were designed to investigate the effects of gamma-aminobutyric acid (GABA) on isolated dog cerebral arteries (basilar artery). On addition of agonists phenylephrine 10 mumol.L-1, 5-HT 10 mumol.L-1, or KCl 25 mmol.L-1, the isometric tension of the contraction increased 0.51 +/- 0.18 g, 0.33 +/- 0.12 g and 0.57 +/- 0.16 g. After GABA at 50 mumol.L-1, the contraction was shown to decrease 0.27 +/- 0.15 g, 0.19 +/- 0.07 g and 0.17 +/- 0.06 g, the maximal relaxation were 45.49% +/- 20.4%, 58.60% +/- 12.96% and 27.75% +/- 15.78%, respectively. But it showed no effect on the contraction induced by high concentration of KCl (45 mmol.L-1). GABA also showed a potent relaxation on the contraction induced by cold Krebs solution (T 28 +/- 0.5 degrees C). The finding suggest that GABA can inhibit the muscle tone induced by various agonists and cooling in isolated dog basilar artery.
Guo
L J
LJ
Department of Pharmacology, Tongji Medical University, Wuhan.
Qu
L
L
Lee
T J
TJ
D000818:Animals; D001488:Basilar Artery / Q000187:drug effects; D004285:Dogs; D005260:Female; D066298:In Vitro Techniques; D008297:Male; D009126:Muscle Relaxation / Q000187:drug effects*; D009131:Muscle, Smooth, Vascular / Q000187:drug effects*; D010656:Phenylephrine / Q000037:antagonists & inhibitors; D014662:Vasoconstrictor Agents / Q000037:antagonists & inhibitors; D005680:gamma-Aminobutyric Acid / Q000494:pharmacology*
D014662:Vasoconstrictor Agents; D010656:Phenylephrine; D005680:gamma-Aminobutyric Acid