异丙肾上腺素的神经元外积聚对灌注大鼠心脏中cAMP产生的影响。

Effects of extraneuronal accumulation of isoprenaline on cAMP production in perfused rat heart.

作者信息

Akimoto Y, Kurahashi K, Fujiwara M

机构信息

Department of Pharmacology, Faculty of Medicine, Kyoto University, Japan.

出版信息

Jpn J Pharmacol. 1990 Jul;53(3):375-80. doi: 10.1254/jjp.53.375.

DOI:10.1254/jjp.53.375

PMID:2167993

Abstract

The effects of extraneuronal accumulation of isoprenaline on the level of cAMP in perfused rat hearts were investigated. When catechol-O-methyl transferase (COMT) was intact, perfusion with isoprenaline (10(-6) M) for 5 min and 30 min (low accumulation of isoprenaline in the heart) enhanced the cAMP level. Propranolol (10(-6) M) significantly decreased the high level of cAMP produced by the perfusion with isoprenaline for 5 min and 30 min (low accumulation of isoprenaline). When COMT was inhibited by tropolone, perfusion with isoprenaline (10(-6) M) for 5 min (slight accumulation of isoprenaline in the heart) slightly increased the level of cAMP, while perfusion for 30 min (high accumulation of isoprenaline in the heart) did not increase the level of cAMP. Propranolol (10(-6) M) significantly decreased the cAMP level produced by 5 min perfusion with isoprenaline, but did not change the level by 30 min perfusion. The perfusion length (5 min and 30 min) and COMT inhibition by tropolone (10(-4) M) in the absence of isoprenaline did not affect cAMP levels. These results suggest that extraneuronally accumulated isoprenaline may inhibit the adenylate cyclase in perfused rat hearts.

摘要

研究了异丙肾上腺素在神经外积聚对灌注大鼠心脏中cAMP水平的影响。当儿茶酚-O-甲基转移酶（COMT）完整时，用异丙肾上腺素（10⁻⁶ M）灌注5分钟和30分钟（心脏中异丙肾上腺素积聚较少）可提高cAMP水平。普萘洛尔（10⁻⁶ M）显著降低了用异丙肾上腺素灌注5分钟和30分钟（异丙肾上腺素积聚较少）所产生的高水平cAMP。当COMT被色酮抑制时，用异丙肾上腺素（10⁻⁶ M）灌注5分钟（心脏中异丙肾上腺素轻度积聚）可使cAMP水平略有升高，而灌注30分钟（心脏中异丙肾上腺素大量积聚）则不会提高cAMP水平。普萘洛尔（10⁻⁶ M）显著降低了用异丙肾上腺素灌注5分钟所产生的cAMP水平，但对灌注30分钟所产生的水平没有影响。在无异丙肾上腺素的情况下，灌注时间（5分钟和30分钟）以及色酮（10⁻⁴ M）对COMT的抑制作用均不影响cAMP水平。这些结果表明，神经外积聚的异丙肾上腺素可能会抑制灌注大鼠心脏中的腺苷酸环化酶。