HNS-32, an azulene-1-carboxamidine derivative, is an originally synthesized antiarrhythmic compound. Its cardiovascular effects after oral administration (1-10 mg/kg) were assessed using the pentobarbital-anesthetized in vivo rat model in comparison with those of verapamil (3 mg/kg, p.o.). Verapamil decreased the heart rate and mean blood pressure and prolonged the PR interval without changing the QRS width (n = 6). Similar results were observed for HNS-32 except that the QRS width was prolonged by the highest dose and the effects occurred slowly and lasted longer. These results suggest that HNS-32 is an orally active slowly-acting calcium plus sodium channel blocker.

2002-01-01·Pharmacology4区 · 医学

Effects of HNS-32, a Novel Antiarrhythmic Agent, on Guinea-Pig Myocardium

4区 · 医学

Article

作者: Tanaka, Hikaru ; Saitoh, Mariko ; Shigenobu, Koki ; Noguchi, Kazuo ; Saitoh, Masaki ; Tanaka, Yoshio ; Masumiya, Haruko ; Nakazawa, Tomoo ; Kase, Junya ; Hashimoto, Keitaro

The electrophysiological and mechanical effects of HNS-32, a novel azulene-1-carboxamidine derivative with antiarrhythmic activity, were studied in isolated guinea-pig myocardial preparations. HNS-32 (10–6–10–4 mol/l) concentration-dependently decreased the maximum rate of rise (Vmax) of action potential in isolated papillary muscle; the potency was the same or slightly higher than that of disopyramide. At 10–4 mol/l, HNS-32 also shortened the action potential duration (APD) and depolarized the resting membrane potential; these effects were similar to those of 10–5 mol/l verapamil. HNS-32 (10–7–10–4 mol/l), as well as verapamil (10–8–10–5 mol/l) and disopyramide (10–6–10–3 mol/l), had concentration-dependent negative chronotropic and negative inotropic effects on isolated right atrial and right ventricular papillary muscle preparations, respectively. The concentration-response relationship for the positive chronotropic effect of isoproterenol was not affected by HNS-32 (10–5 mol/l). In isolated ventricular myocytes, HNS-32 (10–6–10–4 mol/l) concentration-dependently inhibited the peak amplitude of the L-type Ca2+ current. These results suggest that NHS-32 has Vmax reducing activity on myocardial tissue, which may be responsible for antiarrhythmic effect. The drug may also have additional effect on the Ca2+ channel at higher concentrations.

2001-02-14·Naunyn-Schmiedeberg's Archives of Pharmacology4区 · 医学

HNS-32, a novel azulene-1-carboxamidine derivative, inhibits nifedipine-sensitive and -insensitive contraction of the isolated rabbit aorta

4区 · 医学

Article

作者: Keitaro Hashimoto ; Fumiko Yamaki ; Akiko Mitani ; Toshiyasu Imai ; Tomoo Nakazawa ; Kazuo Noguchi ; Koki Shigenobu ; Shinnosuke Someya ; Yoshio Tanaka ; Masaki Saitoh ; Kazuoki Otsuka ; Tomomi Igarashi ; Hikaru Tanaka

The vasorelaxant profile of a novel azulene-1-carboxamidine derivative, HNS-32 [N1,N1-dimethyl-N2-(2-pyridylmethyl)-5-isopropyl-3,8-dimethyl-azulene-1-carboxamidine, CAS 186086-10-2], was investigated in the isolated rabbit aorta precontracted with high KCl, noradrenaline (NA) or phorbol 12, 13-dibutyrate (PDBu) and compared with those of nifedipine and nitroglycerin. In preparations without endothelium, HNS-32 elicited concentration-dependent, full inhibition of contractions elicited by high KCI (80 mM), NA (3x10(-6) M) or PDBu (10(-6) M). In contrast, nifedipine inhibited only the contraction elicited by membrane depolarization with high KCl. Nitroglycerin also attenuated high-KCl-, NA- and PDBu-elicited contractions effectively, although full suppression was obtained only for NA-elicited contraction. Whilst the relaxant effect of HNS-32 was not affected by the presence of endothelium, the relaxant response to acetylcholine was endothelium dependent. Addition of excess Ca2+ restored both the HNS-32-reduced tension in muscle precontracted with high KCI and the nifedipine-mediated tension decrease. Relaxation elicited by HNS-32 was not affected by the adenylate cyclase inhibitor, 9-(tetrahydro-2'-furyl)adenine (SQ 22,536, 10(-4) M), the soluble guanylate cyclase inhibitor, 1H-(1,2,4)-oxadiazolo-(4,3-a)-quinoxalin-1-one (ODQ, 10(-5) M) or a cocktail of K+ channel blockers (glybenclamide 10(-6) M, tetraethylammonium 2x10(-3) M, apamin 10(-7) M, 4-aminopyridine 10(-4) M and Ba2+ 10(-5) M). These findings indicate that HNS-32 inhibits both L-type Ca2+ channel-dependent and -independent vascular contraction. Blockade of Ca2+ entry through L-type Ca2+ channels may be involved in the inhibitory effect of HNS-32 on the contraction due to membrane depolarization with high KCl. On the other hand, HNS-32 seems to inhibit Ca2+ channel-independent contraction via mechanism(s) other than elevation of cyclic nucleotides (cAMP and cGMP) and opening of K+ channels.

100 项与 HNS-32 相关的药物交易

登录后查看更多信息