Wright I K, Kendall D A, Wilson V G
Department of Physiology and Pharmacology, Medical School, Queen's Medical Centre, Nottingham, UK.
Naunyn Schmiedebergs Arch Pharmacol. 1995 Aug;352(2):113-20. doi: 10.1007/BF00176763.
The aim of this study was to use a 3H-adenine pre-labelling technique to characterise the effect of alpha 2-adrenoceptor activation on forskolin-stimulated cyclic AMP accumulation in the isolated porcine palmar lateral vein. Forskolin (10(-7)-10(-4) M) stimulated 3H-cyclic AMP accumulation in the isolated porcine palmar lateral vein in a biphasic and concentration-dependent manner. In the absence of the cyclic AMP-selective phosphodiesterase inhibitor rolipram, forskolin stimulated 3H-cyclic AMP accumulation approximately 7-8 fold. The response reached a peak after 5 min. In the presence of rolipram (10(-5) M), basal 3H-cyclic AMP levels were approximately 70% higher than in its absence (basal: 1823 +/- 57 dpm; rolipram: 3088 +/- 229, n = 3) and forskolin (3 x 10(-5) M) stimulated 3H-cyclic AMP accumulation approximately 8 fold. The latter response reached a plateau 10 min after the addition of forskolin. In all subsequent studies, the tissues were incubated with forskolin (3 x 10(-5) M) for 5 min in the absence of rolipram. Noradrenaline (NA; 10(-9)-10(-4) M) and UK14304 (10(-9)-10(-4) M) inhibited forskolin-stimulated 3H-cyclic AMP accumulation in a concentration-dependent manner with mean pIC50 values of 7.61 +/- 0.37 (n = 4) and 7.76 +/- 0.23 (n = 5), respectively. With either NA or UK14304, the maximal inhibition of the forskolin response obtained was approximately 75%. Neither NA (10(-4) M) nor UK14304 (10(-4) M) altered basal 3H-cyclic AMP levels.(ABSTRACT TRUNCATED AT 250 WORDS)
本研究的目的是使用³H-腺嘌呤预标记技术来表征α₂-肾上腺素能受体激活对福斯高林刺激的离体猪掌外侧静脉中环磷酸腺苷（cAMP）积累的影响。福斯高林（10⁻⁷ - 10⁻⁴ M）以双相和浓度依赖性方式刺激离体猪掌外侧静脉中³H-cAMP的积累。在不存在cAMP选择性磷酸二酯酶抑制剂咯利普兰的情况下，福斯高林刺激³H-cAMP积累约7 - 8倍。反应在5分钟后达到峰值。在存在咯利普兰（10⁻⁵ M）的情况下，基础³H-cAMP水平比不存在时高约70%（基础：1823 ± 57 dpm；咯利普兰：3088 ± 229，n = 3），福斯高林（3×10⁻⁵ M）刺激³H-cAMP积累约8倍。后者的反应在加入福斯高林10分钟后达到平台期。在所有后续研究中，组织在不存在咯利普兰的情况下与福斯高林（3×10⁻⁵ M）孵育5分钟。去甲肾上腺素（NA；10⁻⁹ - 10⁻⁴ M）和UK14304（10⁻⁹ - 10⁻⁴ M）以浓度依赖性方式抑制福斯高林刺激的³H-cAMP积累，平均pIC50值分别为7.61 ± 0.37（n = 4）和7.76 ± 0.23（n = 5）。使用NA或UK14304时，对福斯高林反应的最大抑制约为75%。NA（10⁻⁴ M）和UK14304（10⁻⁴ M）均未改变基础³H-cAMP水平。（摘要截断于250字）
