caa a22 4500 47707250X CHVBK 20180405111430.0 cr unu---uuuuu 170330e19961101xx s 000 0 eng 10.1007/BF00051000 doi (NATIONALLICENCE)springer-10.1007/BF00051000 Kitada Yoshimi Pharmaceutical Laboratory I, Yokohama Research Center, Mitsubishi Chemical Corporation, Yokohama, Japan aut Contrasting effects of betaxolol and propranolol on Ca2+-activated contractions in skinned fibers from canine coronary arteries and ventricular muscles [Elektronische Daten] [Yoshimi Kitada] Summary: The effects of some beta-adrenoceptor antagonists (atenolol, betaxolol, bunitrolol, labetalol, pindolol, and propranolol) on Ca2+ (pCa 5.8)-activated tension development in chemically skinned fibers from canine coronary artery and right ventricular trabeculae were studied. In skinned coronary arteries, Ca2+-activated tension development was decreased by betaxolol and propranolol at concentrations of more than 10−5 and 10−4 M, respectively. The pCa-tension relationships were shifted to the right and down by betaxolol. In contrast, in skinned cardiac muscle Ca2+-activated tension development was increased by betaxolol and propranolol at the same range of concentrations as in coronary arteries, with no change in maximum tension. The pCa-tension relation was shifted to the left by betaxolol. Other beta-adrenoceptor antagonists (atenolol, bunitrolol, labetalol, and pindolol) had no effect on Ca2+-induced contraction in either muscle type. These results indicate that among beta-adrenoceptor antagonists, only betaxolol and propranolol can directly modulate the Ca2+ sensitivity of myofilaments and have opposite effects on the contractile system in canine cardiac and vascular smooth muscle. Kluwer Academic Publishers, 1996 betaxolol nationallicence propranolol nationallicence Ca2+ sensitivity nationallicence cardiac muscle nationallicence smooth muscle nationallicence skinned fibers nationallicence contractile protein nationallicence Cardiovascular Drugs and Therapy Kluwer Academic Publishers 10/5(1996-11-01), 581-586 0920-3206 10:5<581 1996 10 10557 https://doi.org/10.1007/BF00051000 text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1007/BF00051000 text/html Onlinezugriff via DOI NATIONALLICENCE 100 1- Kitada Yoshimi Pharmaceutical Laboratory I, Yokohama Research Center, Mitsubishi Chemical Corporation, Yokohama, Japan aut NATIONALLICENCE 773 0- Cardiovascular Drugs and Therapy Kluwer Academic Publishers 10/5(1996-11-01), 581-586 0920-3206 10:5<581 1996 10 10557 Metadata rights reserved Springer special CC-BY-NC licence nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-springer