Kaba H, Saito H, Otsuka K, Seto K
Jpn J Physiol. 1986;36(4):795-9. doi: 10.2170/jjphysiol.36.795.
Noradrenaline (NA), but not clonidine applied microiontophoretically, inhibited the firing of neurons in the rat A1 noradrenergic region, whereas intravenous clonidine dose-dependently inhibited their firing (ED50 = 18.3 micrograms/kg). The NA-induced inhibition was blocked by the beta-antagonist timolol, but not by the alpha-antagonists phentolamine or piperoxane. These results suggest that neurons in the A1 region possess beta-adrenoceptors rather than alpha-adrenoceptors near their cell bodies, and that systemically administered clonidine acts indirectly on these cells.
微量离子电泳施加去甲肾上腺素（NA）而非可乐定，可抑制大鼠A1去甲肾上腺素能区域神经元的放电，而静脉注射可乐定则呈剂量依赖性地抑制其放电（半数有效量=18.3微克/千克）。NA诱导的抑制作用可被β拮抗剂噻吗洛尔阻断，但不能被α拮抗剂酚妥拉明或哌罗克生阻断。这些结果表明，A1区域的神经元在其细胞体附近具有β肾上腺素能受体而非α肾上腺素能受体，且全身给药的可乐定间接作用于这些细胞。
