Hirano T
J Auton Nerv Syst. 1981 Nov;4(4):339-50. doi: 10.1016/0165-1838(81)90037-0.
Two types of adrenal nerve fibers, AD and NA types, were identified by the presence or absence of inhibition of efferent activity after an intracarotid injection of isoproterenol (a beta-adrenergic stimulant). Efferent activity of both types was suppressed by adrenaline or noradrenaline injection. In AD-type fibers, suppression due to adrenaline or isoproterenol injection was blocked by a beta-adrenergic blocking agent (propranolol). In NA type fibers, the suppressive effect of adrenaline or noradrenaline was blocked by an alpha-adrenergic blocking agent (phenoxybenzamine). Dose-response characteristics showed that in AD-type fibers suppressive effect of adrenaline was always larger than that of noradrenaline, whilst in NA type fibers the two catecholamines caused the same degree of suppression of nerve activity. Two negative feedback loops for catecholamine secretion are suggested; one is between adrenaline level in the circulating blood and AD type nerve activity mediated be beta-adrenergic receptors, and the other is between noradrenaline level and NA type nerve activity, mediated by alpha-adrenergic receptors. Considering that AD-type fibers terminate on adrenaline-storing cells and NA type fibers terminate on noradrenaline-storing cells, it is suggested that beta-receptor--AD-type fibers--adrenaline-storing cell system controls adrenaline level and alpha-receptor--NA type fibers--noradrenaline-storing cell system controls noradrenaline level.
通过颈内注射异丙肾上腺素（一种β-肾上腺素能兴奋剂）后传出活动是否受到抑制，确定了两种肾上腺神经纤维，即AD型和NA型。两种类型的传出活动都可被肾上腺素或去甲肾上腺素注射所抑制。在AD型纤维中，肾上腺素或异丙肾上腺素注射所致的抑制可被β-肾上腺素能阻断剂（普萘洛尔）阻断。在NA型纤维中，肾上腺素或去甲肾上腺素的抑制作用可被α-肾上腺素能阻断剂（酚苄明）阻断。剂量-反应特征表明，在AD型纤维中，肾上腺素的抑制作用总是大于去甲肾上腺素，而在NA型纤维中，两种儿茶酚胺对神经活动的抑制程度相同。提示存在两种儿茶酚胺分泌的负反馈环；一个是循环血液中的肾上腺素水平与由β-肾上腺素能受体介导的AD型神经活动之间的负反馈环，另一个是去甲肾上腺素水平与由α-肾上腺素能受体介导的NA型神经活动之间的负反馈环。考虑到AD型纤维终止于储存肾上腺素的细胞，NA型纤维终止于储存去甲肾上腺素的细胞，提示β-受体-AD型纤维-储存肾上腺素的细胞系统控制肾上腺素水平，α-受体-NA型纤维-储存去甲肾上腺素的细胞系统控制去甲肾上腺素水平。
