Abstract:

In this project, mitochondrial respiratory states were measured at different temperatures (20, 26, and 30 o‌C) to characterize temperature effects on mitochondria function in heart tissue and red muscle of mahi mahi. Furthermore, the effects of acute temperature changes on mitochondrial respiratory states were examined by changing the temperature from 20 to 30‌o‌C and vice versa.

Suggested Citation:

Lau, G., Cox, G.. 2019. Temperature effects on mitochondrial function in heart and red muscle of mahi-mahi. Distributed by: GRIIDC, Harte Research Institute, Texas A&M University–Corpus Christi. doi:10.7266/n7-wyp8-rc91

Purpose:

​As mahi naturally traverse through wide temperature gradients, the goal of this study was to characterize mitochondrial respiratory states assayed at different temperatures​ that mahi would experience in the wild​ (20, 26, and 30C) and also in response to acute temperature changes (20 to 30C and vice versa).

Data Parameters and Units:

​State II (respiration on endogenous substrates), III (ADP-stimulated respiration rate), IV (oligomycin-induced leak respiration rate), electron transport system capacity (FCCP-uncoupled respiration rate) were assessed when fibres were supplemented with various substrates pyruvate and malate (PM) to donate to mitochondrial complex I, and succinate (S) to donate to mitochondrial complex II. More details can be found here: http://bioblast.at/index.php/MitoPedia:_Respiratory_states. The unit of the numbers (respiratory rates) under the headings of State II (PMG), State III (PMG), State IV0, State III (PMGS) and ETS Capacity and equivalent headings in excel file is (pmol O2/sec/mg protein). Note: State II and State III should be labelled as “State II (PMGS) “ and "State III (PMGS)”.

Methods:

Permeabilized heart and red muscles tissue were used in the experiment. The medium used is MiR05 (0.5mM EGTA, 3mM MgCl2.6H2O, 60mM K-lactobionic acid, 20mM taurine, 10mM KH2PO4, 20mM HEPES, 110mM sucrose, 1g/L BSA, at pH7.1) (Gnaiger et al., 2000). High-resolution respirometry was used to acquire data. There was daily calibration of polarographic oxygen sensors with air saturated and anoxic MiR05 buffer at the assay temperatures (20, 26, and 30‌o‌C).

Instruments:

Oroboros oxygraph (Innsbruck, Austria).

Provenance and Historical References:

Gnaiger, E., Kuznetsov, A. V., Schneeberger, S., Seiler, Rü., Brandacher, G., Steurer, W., & Margreiter, R. (2000). Mitochondria in the Cold. Life in the Cold, 431–442. doi:10.1007/978-3-662-04162-8_45

Individual Files: