Brighenti L, Puviani A C, Gavioli M E, Ottolenghi C
Gen Comp Endocrinol. 1987 Jun;66(3):306-13. doi: 10.1016/0016-6480(87)90239-5.
Isolated catfish hepatocytes were treated with epinephrine, norepinephrine, isoproterenol, and phenylephrine in the presence or in the absence of propranolol or phentolamine as beta and alpha inhibitors, respectively. Glycogen phosphorylase a activity and glycogen content, as well as glucose released from cells, were tested. Phosphorylase activity was stimulated by all the catecholamines and was accompanied by a decrease of glycogen content in cells and by an increase in glucose output into the medium. Whereas phentolamine did not affect the catecholamine action on any parameter considered, propranolol inhibited the effect of epinephrine, norepinephrine, and phenylephrine, but hardly altered that of isoproterenol. The effect of epinephrine and norepinephrine, as modified by propranolol and not by phentolamine, is consistent with a beta action of these catecholamines. The fact that propranolol and not phentolamine inhibited the phenylephrine effect indicates that in catfish hepatocytes phenylephrine behaves as a beta agonist and/or that propranolol may also bind to alpha receptors. Results also indicate that in catfish liver cells isoproterenol, whose effect is scarcely influenced by propranolol, is not a pure beta agonist.
分离得到的鲶鱼肝细胞在分别存在或不存在作为β抑制剂的普萘洛尔或作为α抑制剂的酚妥拉明的情况下，用肾上腺素、去甲肾上腺素、异丙肾上腺素和苯肾上腺素进行处理。检测糖原磷酸化酶a活性、糖原含量以及细胞释放的葡萄糖。所有儿茶酚胺均刺激磷酸化酶活性，并伴随着细胞内糖原含量的降低以及培养基中葡萄糖输出的增加。而酚妥拉明对所考虑的任何参数的儿茶酚胺作用均无影响，普萘洛尔抑制肾上腺素、去甲肾上腺素和苯肾上腺素的作用，但几乎不改变异丙肾上腺素的作用。普萘洛尔而非酚妥拉明对肾上腺素和去甲肾上腺素作用的改变，与这些儿茶酚胺的β作用一致。普萘洛尔而非酚妥拉明抑制苯肾上腺素作用这一事实表明，在鲶鱼肝细胞中苯肾上腺素表现为β激动剂和/或普萘洛尔也可能与α受体结合。结果还表明，在鲶鱼肝细胞中，其作用几乎不受普萘洛尔影响的异丙肾上腺素不是一种纯粹的β激动剂。
