Abstract
1. 1. The effects of the physiological levels of corticotropin-releasing factor (CRF) on isolated guinea-pig ventricular myocardium were studied using a force transducer and standard microelectrode techniques. 2. 2. CRF increased the contractile force of muscles concentration-dependently in normal Tyrode and a high-K + (27 mM) solution. The positive inotropic effect of CRF was associated with a significant enhancement of the slow action potentials of partially depolarized muscles in high-K + solution. CRF potentiated the effect of increasing Ca 2+ concentration of Tyrode solution. 3. 3. The inotropic effect of CRF was reduced in the presence of diltiazem, and suppressed by phentolamine, metoclopramide, and cimetidine, but was not affected by propranolol and cold condition. 4. 4. It is suggested that an increase in the slow inward Ca 2+ current induced by CRF plays an important role in its positive inotropic effect and that its effect differs from that of cardiotonic steroids.
Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
