Nedergaard O A
Department of Pharmacology, School of Medicine, Odense University, Denmark.
Naunyn Schmiedebergs Arch Pharmacol. 1987 Aug;336(2):176-82. doi: 10.1007/BF00165802.
The aim of the present work was to demonstrate the presence of presynaptic beta-adrenoceptors in the rabbit isolated pulmonary artery by investigating the effect of isoprenaline on 3H-noradrenaline (3H-NA) release evoked by electrical field stimulation. (-)-Isoprenaline (10(-7)-10(-6) mol/l) had no effect on the 3H-overflow evoked by stimulation (3 Hz) of the pulmonary artery preloaded with 3H-NA. At 10(-5) mol/l, (-)-isoprenaline reduced the 3H-overflow by maximally 39%. (-)-Isoprenaline (10(-5) mol/l) caused an inhibition that remained almost constant with time. The same results were obtained with (-)-isoprenaline (10(-7)-3 X 10(-5) mol/l) in the presence of cocaine (3 X 10(-5) mol/l), corticosterone (4 X 10(-5) mol/l), and the catechol-O-methyltransferase inhibitor U-0521 (3',4'-dihydroxy-2-methylpropiophenone) (10(-4) mol/l). In the presence of cocaine plus corticosterone, (-)-isoprenaline (3 X 10(-10)-10(-7) mol/l) had no effect on the 3H-overflow evoked by stimulation at 1 Hz. At 10(-6) mol/l, (-)-isoprenaline slightly reduced the 3H-overflow. At 10 Hz, (-)-isoprenaline (10(-6)-3 X 10(-5) mol/l) decreased the 3H-overflow and had no effect at 10(-7) mol/l. In the presence of either rauwolscine (10(-6) mol/l), phentolamine (10(-6) mol/l) or the phosphodiesterase inhibitor ICI 63,197 (3 X 10(-5) mol/l), (-)-isoprenaline (10(-7)-10(-6) mol/l) did not enhance the stimulation-evoked 3H-overflow. (+/-)-Propranolol (10(-7)-10(-5) mol/l) did not alter the stimulation-evoked 3H-overflow.(ABSTRACT TRUNCATED AT 250 WORDS)
本研究的目的是通过研究异丙肾上腺素对电场刺激诱发的兔离体肺动脉中3H-去甲肾上腺素（3H-NA）释放的影响，来证明突触前β-肾上腺素能受体的存在。（-）-异丙肾上腺素（10^(-7)-10^(-6)mol/L）对预先加载3H-NA的肺动脉刺激（3Hz）诱发的3H释放无影响。在10^(-5)mol/L时，（-）-异丙肾上腺素使3H释放最大减少39%。（-）-异丙肾上腺素（10^(-5)mol/L）引起的抑制作用随时间几乎保持恒定。在可卡因（3×10^(-5)mol/L）、皮质酮（4×10^(-5)mol/L）和儿茶酚-O-甲基转移酶抑制剂U-0521（3'，4'-二羟基-2-甲基苯丙酮）（10^(-4)mol/L）存在的情况下，（-）-异丙肾上腺素（10^(-7)-3×10^(-5)mol/L）也得到了相同的结果。在可卡因加皮质酮存在的情况下，（-）-异丙肾上腺素（3×10^(-10)-10^(-7)mol/L）对1Hz刺激诱发的3H释放无影响。在10^(-6)mol/L时，（-）-异丙肾上腺素使3H释放略有减少。在10Hz时，（-）-异丙肾上腺素（10^(-6)-3×10^(-5)mol/L）使3H释放减少，而在10^(-7)mol/L时无影响。在存在萝芙木碱（10^(-6)mol/L）、酚妥拉明（10^(-6)mol/L）或磷酸二酯酶抑制剂ICI 63,197（3×10^(-5)mol/L）的情况下，（-）-异丙肾上腺素（10^(-7)-10^(-6)mol/L）不会增强刺激诱发的3H释放。（±）-普萘洛尔（10^(-7)-10^(-5)mol/L）不会改变刺激诱发的3H释放。（摘要截短至250字）
