Abstract
1. The effects of CPU-23 (1-(1-[(6-methoxyl)-naphth-2-yl])-propyl-2-(1-piperidine)-acetyl-6 ,7- dimethyoxy-1,2,3,4-tetra-hydroisoquinoline) were studied on mechanical and electrical activities, and intracellular free calcium ([Ca2+]i) of isolated cardiac tissues in order to investigate its spectrum and mechanisms of action in the heart. Its antiarrhythmic and haemodynamic effects in pentobarbitone-anaesthetized rats subjected to coronary artery ligation were also evaluated. 2. CPU-23 at 10(-6)-10(-4) M markedly inhibited slow action potential characteristics in guinea-pig papillary muscles and pace-maker action potential of rabbit sinoatrial node. It affected fast action potential only at 10(-4) M. None of the effects of CPU-23 was reversed by washout for up to 2 h. 3. Like nifedipine and diltiazem, CPU-23 decreased the heart rate of the isolated perfused heart of the rat. However, in contrast to these two classical calcium antagonists which dose-dependently inhibited the force of contraction, CPU-23 inhibited and stimulated the force of contraction at 10(-7)-3 x 10(-6) M and 10(-5) M, respectively. 4. CPU-23 at 10(-6)-10(-5) M inhibited the KCl-induced [Ca2+]i increase in the Ca2+ medium, but did not affect the caffeine-induced [Ca2+]i increase in the Ca(2+)-free medium in isolated ventricular myocytes. 5. CPU-23 at 1-5 mg kg-1 reduced dose-dependently ventricular arrhythmias including ventricular ectopic beats, VT and VF as well as mortality during coronary artery ligation. At 2.5-5 mg kg-1 it even abolished VF, which was accompanied by 100% survival.(ABSTRACT TRUNCATED AT 250 WORDS)
Full text
PDF






Selected References
These references are in PubMed. This may not be the complete list of references from this article.
- Au T. L., Curtis M. J., Walker M. J. Effects of (-), (+/- ), and (+) verapamil on coronary occlusion-induced mortality and infarct size. J Cardiovasc Pharmacol. 1987 Sep;10(3):327–331. doi: 10.1097/00005344-198709000-00012. [DOI] [PubMed] [Google Scholar]
- Clark C., Foreman M. I., Kane K. A., McDonald F. M., Parratt J. R. Coronary artery ligation in anesthetized rats as a method for the production of experimental dysrhythmias and for the determination of infarct size. J Pharmacol Methods. 1980 Jun;3(4):357–368. doi: 10.1016/0160-5402(80)90077-7. [DOI] [PubMed] [Google Scholar]
- Conti C. R., Pepine C. J., Feldman R. L., Hill J. A. Calcium antagonists. Cardiology. 1985;72(5-6):297–321. doi: 10.1159/000173886. [DOI] [PubMed] [Google Scholar]
- Curtis M. J., MacLeod B. A., Walker M. J. Antiarrhythmic actions of verapamil against ischaemic arrhythmias in the rat. Br J Pharmacol. 1984 Oct;83(2):373–385. doi: 10.1111/j.1476-5381.1984.tb16497.x. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Curtis M. J., Walker M. J. The mechanism of action of calcium antagonists on arrhythmias in early myocardial ischaemia: studies with nifedipine and DHM9. Br J Pharmacol. 1988 Aug;94(4):1275–1286. doi: 10.1111/j.1476-5381.1988.tb11648.x. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Curtis M. J., Walker M. J. The mechanism of action of the optical enantiomers of verapamil against ischaemia-induced arrhythmias in the conscious rat. Br J Pharmacol. 1986 Sep;89(1):137–147. doi: 10.1111/j.1476-5381.1986.tb11129.x. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Dong H., Lee C. M., Huang W. L., Peng S. X. Cardiovascular effects of substituted tetrahydroisoquinolines in rats. Br J Pharmacol. 1992 Sep;107(1):262–268. doi: 10.1111/j.1476-5381.1992.tb14496.x. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Fagbemi O., Parratt J. R. Calcium antagonists prevent early post-infarction ventricular fibrillation. Eur J Pharmacol. 1981 Nov 5;75(4):179–185. doi: 10.1016/0014-2999(81)90543-4. [DOI] [PubMed] [Google Scholar]
- Fleckenstein A. Specific pharmacology of calcium in myocardium, cardiac pacemakers, and vascular smooth muscle. Annu Rev Pharmacol Toxicol. 1977;17:149–166. doi: 10.1146/annurev.pa.17.040177.001053. [DOI] [PubMed] [Google Scholar]
- Freedman D. D., Waters D. D. 'Second generation' dihydropyridine calcium antagonists. Greater vascular selectivity and some unique applications. Drugs. 1987 Nov;34(5):578–598. doi: 10.2165/00003495-198734050-00005. [DOI] [PubMed] [Google Scholar]
- Grynkiewicz G., Poenie M., Tsien R. Y. A new generation of Ca2+ indicators with greatly improved fluorescence properties. J Biol Chem. 1985 Mar 25;260(6):3440–3450. [PubMed] [Google Scholar]
- Huang W. L., Song X. Q., Peng S. X., Huang Z. Y. [The synthesis and biological activity of substituted tetrahydroisoquinoline compounds]. Yao Xue Xue Bao. 1990;25(11):815–823. [PubMed] [Google Scholar]
- Huang X. D., Wong T. M. Morphine and (D-Ala2, NMe-Phe4, Gly-ol)-enkephalin increase the intracellular free calcium in isolated rat myocytes--effect of naloxone or pretreatment with morphine. Life Sci. 1991;48(11):1101–1107. doi: 10.1016/0024-3205(91)90512-a. [DOI] [PubMed] [Google Scholar]
- Ledda F., Mantelli L., Mugelli A. Blockade by burimamide of the restorative effect of histamine in tetrodotoxin-treated heart preparations. Br J Pharmacol. 1976 Jun;57(2):247–249. doi: 10.1111/j.1476-5381.1976.tb07474.x. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Ledda F., Mantelli L., Mugelli A. alpha-Sympathomimetic amines and calcium-mediated action potentials in guinea-pig ventricular muscle. Br J Pharmacol. 1980 Aug;69(4):565–571. doi: 10.1111/j.1476-5381.1980.tb07905.x. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Malécot C. O., Trautwein W. On the relationship between V max of slow responses and Ca-current availability in whole-cell clamped guinea pig heart cells. Pflugers Arch. 1987 Sep;410(1-2):15–22. doi: 10.1007/BF00581890. [DOI] [PubMed] [Google Scholar]
- Merillat J. C., Lakatta E. G., Hano O., Guarnieri T. Role of calcium and the calcium channel in the initiation and maintenance of ventricular fibrillation. Circ Res. 1990 Nov;67(5):1115–1123. doi: 10.1161/01.res.67.5.1115. [DOI] [PubMed] [Google Scholar]
- Mugelli A., Amerini S., De Bonfioli Cavalcabo P., Cerbai E., Visentin S. Electrophysiological effects mediated by the stimulation of cardiac beta 2-adrenoceptors with tulobuterol. Cardiovasc Drugs Ther. 1987;1(1):101–107. doi: 10.1007/BF02125839. [DOI] [PubMed] [Google Scholar]
- Ohtsuka M., Yokota M., Kodama I., Yamada K., Shibata S. New generation dihydropyridine calcium entry blockers: in search of greater selectivity for one tissue subtype. Gen Pharmacol. 1989;20(5):539–556. doi: 10.1016/0306-3623(89)90084-0. [DOI] [PubMed] [Google Scholar]
- Opthof T., de Jonge B., Mackaay A. J., Bleeker W. K., Masson-Pevet M., Jongsma H. J., Bouman L. N. Functional and morphological organization of the guinea-pig sinoatrial node compared with the rabbit sinoatrial node. J Mol Cell Cardiol. 1985 Jun;17(6):549–564. doi: 10.1016/s0022-2828(85)80024-9. [DOI] [PubMed] [Google Scholar]
- SELYE H., BAJUSZ E., GRASSO S., MENDELL P. Simple techniques for the surgical occlusion of coronary vessels in the rat. Angiology. 1960 Oct;11:398–407. doi: 10.1177/000331976001100505. [DOI] [PubMed] [Google Scholar]
- Smith H. J., Singh B. N., Nisbet H. D., Norris R. M. Effects of verapamil on infarct size following experimental coronary occlusion. Cardiovasc Res. 1975 Jul;9(4):569–578. doi: 10.1093/cvr/9.4.569. [DOI] [PubMed] [Google Scholar]
