Pharmacological effects of an aldehyde type α/β-adrenoceptor blocking agent with vasodilating properties

Chaw Chi Chiu, Young Tso Lin, Chieh Ho Tsai, Jhy Chong Liang, Lien Chai Chiang, Jiunn Ren Wu, Ing Jun Chen, Jwu Lai Yeh*

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

14 Citations (Scopus)


KMUP 880723 (0.5, 1.0, and 3.0 mg/kg, iv) produced dose-dependent hypotensive and bradycardia responses in pentobarbital-anesthetized Wistar rats. KMUP 880723 (1.0 mg/kg, iv) also markedly inhibited both the tachycardia effects induced by (-)isoproterenol and arterial pressor responses induced by phenylephrine. In the isolated Wistar rat right atria, left atria, and guinea pig tracheal strips, KMUP 880723 competitively antagonized the (-)isoproterenol-induced positive chronotropic effects, inotropic effects, and tracheal relaxation effects in a concentration-dependent manner. The parallel shift to the right of the concentration-response curve of (-)isoproterenol suggested that KMUP 880723 was a β12-adrenoceptor competitive antagonist. The apparent pA2 values were 6.89 ± 0.10 in the right atria, 7.02 ± 0.09 in the left atria, and 6.59 ± 0.11 in the trachea, indicating that KMUP 880723 was a nonselective β-adrenoceptor blocker. In thoracic aorta experiments, KMUP 880723 also produced a competitive antagonism of norepinephrine-induced contraction with a pA2 value of 7.14 ± 0.06. In isolated rat thoracic aorta, KMUP 880723 more potently relaxed the contractions induced by norepinephrine (3 × 10-6 M) than those by high K+ (75 mM). In the radioligand-binding assay, the pKi values of [3H]CGP-12177 binding to rat ventricle and lung membranes were 6.56 and 6.40, respectively, and the value of [3H]prazosin binding to rat brain membranes was 6.66. These results further confirmed the α/β-adrenoceptor blocking activities of KMUP 880723 reported in the functional studies. We conclude that KMUP 880723 is a nonselective β-adrenoceptor antagonist with α-adrenoceptor blocking-associated vasorelaxant activity.

Original languageEnglish
Pages (from-to)391-400
Number of pages10
JournalGeneral Pharmacology: The Vascular System
Issue number6
Publication statusPublished - 2000
Externally publishedYes


  • Intrinsic sympathomimetic activity
  • Radioligand-binding assay
  • Vasorelaxant effect
  • α/β-Adrenoceptor blockade

ASJC Scopus subject areas

  • Pharmacology


Dive into the research topics of 'Pharmacological effects of an aldehyde type α/β-adrenoceptor blocking agent with vasodilating properties'. Together they form a unique fingerprint.

Cite this