Effects of temperature, adrenaline and ryanodine on power production in rainbow trout Oncorhynchus mykiss ventricular trabeculae

H. A. Shiels, E. D. Stevens, A. P. Farrell

    Research output: Contribution to journalArticlepeer-review


    This study is the first to examine the contractility of teleost ventricular muscle in an oscillating muscle preparation. The experiments were designed to test the relative importance of Ca2+ released from the sarcoplasmic reticulum (SR) and Ca2+ influx across the sarcolemma (SL) to cardiac performance in rainbow trout Oncorhynchus mykiss. Adrenaline and ryanodine were used to modulate Ca2+ flux through the SL and SR, respectively. Experiments were conducted at two temperatures (12 °C and 22 °C) (1) to investigate the effect of an acute temperature change (from 12 °C to 22 °C) on power production, and (2) to test the effects of acute temperature change on the relative contributions of the SR and SL Ca2+ flux to power production. Concordant with isometric studies, the results showed that trans-sarcolemmal influx was the major source of Ca2+ (approximately 90%) for cardiac power production at all temperatures. This SL Ca2+ influx was increased with adrenergic stimulation. The power curves generated in this study suggest an optimum frequency for power production of approximately 1.0 Hz at 12 °C, which corresponds well to typical in vivo heart rates for rainbow trout at that temperature. Further, this study indicated that temperature-induced changes in power output cannot be predicted from temperature-induced changes in isometric tension because the temperature-sensitivity of work and power proved to be greater than that of isometric tension. This finding is important because many previous studies have assessed cardiac contractility using only isometric tension.
    Original languageEnglish
    Pages (from-to)2701-2710
    Number of pages9
    JournalJournal of Experimental Biology
    Issue number19
    Publication statusPublished - Oct 1998


    • Adrenaline
    • Isometric tension
    • Oncorhynchus mykiss
    • Power
    • Rainbow trout
    • Ryanodine
    • Temperature
    • Ventricle
    • Work
    • Work loop


    Dive into the research topics of 'Effects of temperature, adrenaline and ryanodine on power production in rainbow trout Oncorhynchus mykiss ventricular trabeculae'. Together they form a unique fingerprint.

    Cite this