alpha- and beta-adrenergic receptors in regulation of ionic transport in frog cornea.
alpha- and beta-adrenergic receptors in regulation of ionic transport in frog cornea.
复制标题
α-和β-肾上腺素能受体调节青蛙角膜离子运输。
作者：
R. Montoreano;O. Candia;P. Cook
本文研究了儿茶酚胺和肾上腺素能阻断剂对离体蛙角膜Cl-和Na+转运的影响。在10（-6）至10（-5）M浓度下，受试的三种儿茶酚胺刺激Cl-转运。α受体阻滞剂酚妥拉明和β受体阻滞剂普萘洛尔可部分抑制10（-6）M肾上腺素产生的刺激。10（-6）M异丙肾上腺素产生的刺激不受10（-5）M酚妥拉明的影响，但可被10（-5）M普萘洛尔完全阻止。10（-5）M去甲肾上腺素产生的刺激可被10（-5）M普萘洛尔完全阻断，部分被10（-5）M酚妥拉明阻断。儿茶酚胺对正常的小Na+转运没有影响。当钠离子转运先前增加的阿替霉素B，肾上腺素和异丙肾上腺素产生一个小的和不一致的刺激作用。去甲肾上腺素无效。它的结论是，α-和β-肾上腺素能受体存在于青蛙角膜和Cl-运输增加的刺激任一受体。对Na+转运的最小影响进一步表明青蛙角膜中Cl-和Na+转运的途径分离。
The effect of catecholamines and adrenergic blocking agents on the transport of Cl- and Na+ of the isolated frog cornea was studied. Cl- transport was stimulated by the three catecholamines tested at 10(-6) to 10(-5) M concentration. The stimulation produced by 10(-6) M epinephrine was partially inhibited by both the alpha-blocker phentolamine and the beta blocker propranolol. The stimulation produced by 10(-6) M isoproterenol was not affected by 10(-5) M phentolamine but was completely prevented by 10(-5) M propranolol. The stimulation produced by 10(-5) M norepinephrine was completely blocked by the 10(-5) M propranolol and partially by 10(-5) M phentolamine. Catecholamines had no effect on the normally small Na+ transport. When the Na+ transport was previously increased by amphotericin B, epinephrine and isoproterenol produced a small and inconsistent stimulatory effect. Norepinephrine was without effect. It is concluded that both alpha- and beta-adrenergic receptors are present in the frog cornea and that the Cl- transport is increased by the stimulation of either receptor. The minimal effect on the Na+ transport further suggests the separation of pathways of the Cl- and Na+ transport in the frog cornea.