caa a22 4500 477120210 CHVBK 20180405111634.0 cr unu---uuuuu 170330e19960401xx s 000 0 eng 10.1007/BF00227894 doi (NATIONALLICENCE)springer-10.1007/BF00227894 Comparison of calcium-current in isolated atrial myocytes from failing and nonfailing human hearts [Elektronische Daten] [Tzu-Hurng Cheng, Fan-Yen Lee, Jeng Wei, Cheng-I Lin] To identify possible alterations of the L-type calcium currents (ICa,L) in cardiomyopathy, ICa,L were recorded in atrial myocytes dissociated from the nonfailing heart (NF) of patients undergoing corrective open-heart surgery and explanted failing heart (FH) of patients with dilated cardiomyopathy undergoing heart transplantation. The patch-clamp technique was applied in the single-electrode whole-cell mode. The electrophysiological properties of ICa,L, including cell capacitance and current density, were similar in atrial myocytes from both groups of patients. Further to identify possible alterations of the myocardial beta-adrenergic pathway in cardiomyopathy, we examined the effects of isoproterenol, forskolin, 8-Br-cAMP and IBMX on ICa,L in both groups of atrial myocytes. Perfusion of isoproterenol (1 μM) significantly increased the peak ICa,L by 515 ± 44% in 6 atrial myocytes from NF but increased only by 135 ± 25% in 27 atrial myocytes from FH. However, forskolin (1 μM) or 8-Br-cAMP (0.1 mM) increased the peak ICa,L to a similar extent in atrial myocytes from NF and FH. IBMX (20 μM) also induced a comparable increase in the peak ICa,L by 213 ± 31% (n=5) and 207 ± 59% (n=4) in atrial myocytes from NF and FH, respectively. The above findings suggest that in atrial myocytes obtained from FH the beta-adrenoceptor numbers might be decreased but no impairment of the signal transduction cascade occurred beyond the GTP binding proteins level. Kluwer Academic Publishers, 1996 human atrial myocytes nationallicence cardiomyopathy nationallicence calcium currents nationallicence β-adrenoceptors nationallicence whole cell clamp nationallicence Cheng Tzu-Hurng Graduate Institute of Life Sciences ,National Defense Medical Center, Taipei, Taiwan, Republic of China aut Lee Fan-Yen Department of Surgery, National Defense Medical Center, Taipei, Taiwan, Republic of China aut Wei Jeng Department of Surgery, National Defense Medical Center, Taipei, Taiwan, Republic of China aut Lin Cheng-I Department of Pharmacology, National Defense Medical Center, Taipei, Taiwan, Republic of China aut Molecular and Cellular Biochemistry Kluwer Academic Publishers 157/1-2(1996-04-01), 157-162 0300-8177 157:1-2<157 1996 157 11010 https://doi.org/10.1007/BF00227894 text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1007/BF00227894 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Cheng Tzu-Hurng Graduate Institute of Life Sciences ,National Defense Medical Center, Taipei, Taiwan, Republic of China aut NATIONALLICENCE 700 1- Lee Fan-Yen Department of Surgery, National Defense Medical Center, Taipei, Taiwan, Republic of China aut NATIONALLICENCE 700 1- Wei Jeng Department of Surgery, National Defense Medical Center, Taipei, Taiwan, Republic of China aut NATIONALLICENCE 700 1- Lin Cheng-I Department of Pharmacology, National Defense Medical Center, Taipei, Taiwan, Republic of China aut NATIONALLICENCE 773 0- Molecular and Cellular Biochemistry Kluwer Academic Publishers 157/1-2(1996-04-01), 157-162 0300-8177 157:1-2<157 1996 157 11010 Metadata rights reserved Springer special CC-BY-NC licence nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-springer