Waldeck B, Widmark E
Eur J Pharmacol. 1985 Jun 19;112(3):349-53. doi: 10.1016/0014-2999(85)90780-0.
Forskolin, a potent activator of adenylate cyclase, and isoprenaline, an unselective beta-adrenoceptor agonist, were studied in vitro on tissues from guinea-pig with respect to relaxation of the carbachol-contracted trachea, increase in the force of contraction of the papillary muscle and depression of subtetanic contractions of the soleus muscle, three well-characterized beta-adrenoceptor-mediated effects. Forskolin and isoprenaline relaxed the trachea and increased the force of contraction of the papillary muscle. Isoprenaline but not forskolin caused a depression of the subtetanic contraction of the soleus muscle. Forskolin did not seem to potentiate the effects of isoprenaline on the tissues studied; the combined effects appeared to be a mere addition. Forskolin did not increase the efficacy of the partial agonist prenalterol either. It is concluded that there is no simple relation between c-AMP generation and the functional response to beta-adrenoceptor agonists. Forskolin should not be used uncritically to probe beta-adrenoceptor-mediated effects.
毛喉素是一种有效的腺苷酸环化酶激活剂，而异丙肾上腺素是一种非选择性β-肾上腺素能受体激动剂。在体外，研究了它们对豚鼠组织的作用，包括对卡巴胆碱收缩的气管的舒张作用、对乳头肌收缩力的增强作用以及对比目鱼肌不完全强直收缩的抑制作用，这三种都是典型的β-肾上腺素能受体介导的效应。毛喉素和异丙肾上腺素可舒张气管并增强乳头肌的收缩力。异丙肾上腺素而非毛喉素可引起比目鱼肌不完全强直收缩的抑制。毛喉素似乎并未增强异丙肾上腺素对所研究组织的作用；联合作用似乎只是简单相加。毛喉素也未增加部分激动剂普瑞特罗的效力。结论是，c-AMP生成与对β-肾上腺素能受体激动剂的功能反应之间不存在简单关系。不应不加批判地使用毛喉素来探究β-肾上腺素能受体介导的效应。
