Brown J H, Makman M H
Proc Natl Acad Sci U S A. 1972 Mar;69(3):539-43. doi: 10.1073/pnas.69.3.539.
A catecholamine-sensitive adenylate cyclase system is present in homogenates of both calf and rat retinas. Dopamine is a more potent activator of the bovine enzyme than is norepinephrine or epinephrine. Cyclic AMP concentrations in intact bovine retina are increased by dopamine, as well as by other catecholamines, and by depolarizing agents. Studies with adrenergic blocking agents suggest that the stimulation of retinal adenylate cyclase by catecholamines cannot be clearly defined in terms of the characteristics of alpha or beta adrenergic receptors. Bovine retina also contains a protein kinase that is stimulated 20-fold by cyclic AMP. It is proposed that dopamine is the major activator of a retinal adenylate cyclase, and that this activation is related to its role as a neurotransmitter.
牛和大鼠视网膜的匀浆中都存在一种对儿茶酚胺敏感的腺苷酸环化酶系统。多巴胺对牛酶的激活作用比去甲肾上腺素或肾上腺素更强。多巴胺以及其他儿茶酚胺和去极化剂均可使完整牛视网膜中的环磷酸腺苷(cAMP)浓度升高。使用肾上腺素能阻滞剂的研究表明,根据α或β肾上腺素能受体的特性,无法明确儿茶酚胺对视网膜腺苷酸环化酶的刺激作用。牛视网膜还含有一种蛋白激酶,它可被环磷酸腺苷激活20倍。有人提出,多巴胺是视网膜腺苷酸环化酶的主要激活剂,这种激活作用与其作为神经递质的作用有关。