Effects of Temperature, Adrenaline and Ryanodine on Power Production in Rainbow Trout Oncorhynchus Mykiss Ventricular Trabeculae

• DOI: 10.1242/jeb.201.19.2701
• Publication Date: 2021-04-23T23:28:31Z
• Authors: H. A. Shiels; E. D. Stevens; A. P. Farrell
• Keywords: Contractility; Sarcolemma; Cardiac muscle

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