Gnaiger 1989 Soc Exp Biol Seminar Series
|Gnaiger E, Shick JM, Widdows J (1989) Metabolic microcalorimetry and respirometry of aquatic animals. In: Techniques in comparative respiratory physiology. An experimental approach. Bridges CR, Butler PJ (eds), Soc Exp Biol Seminar Series, Cambridge Univ Press, London:113-35.|
Abstract: Cellular energy transformations are accompanied by heat changes indicative of physiological and metabolic activities of living organisms. The thermodynamic approach by metabolic (direct) calorimetry reveals the integrated sum of all enthalpy changes occurring within the experimental chamber, that is the living open system and its environment. The term microcalorimetry is loosely defined, indicating that heat flux is measured in the range of 1 to 1000 µW, equivalent to 0.0022 to 2.2 nmol O2 s-1 or 8 to 8000 µmol h-1 for aerobic metabolism. Due to recent technological advancements, metabolic microcalorimetry has become a sensitive, non-invasive method for the study of respiration and complex metabolic process in animals.
The classic method of indirect calorimetry depends on the calculation of heat changes from measured oxygen consumption and theoretical oxycaloric equivalents. This indirect method is extended by including anaerobic metabolite changes in the calculation of theoretical heat changes. Comparison of direct and indirect calorimetry constitutes the thermodynamic energy balance method, the crucial test for a complete biochemical description of net processes under various metabolic states. Thermochemical interpretation of biochemical and calorimetric data is not only required in energy balance studies, it is important for understanding the functional significance of heat flux in physiological energetics. Specifically, calorespirometry - the simultaneous measurement of heat flux and oxygen flux in an open flow or perfusion system - enables the partitioning of total heat flux into aerobic and anaerobic components.
- Dedicated to Kjell Johansen
• Keywords: CaloRespirometry, microcalorimetry, open-flow respirometry, closed-chamber respirometry
• O2k-Network Lab: AT Innsbruck Gnaiger E
Labels: MiParea: Respiration, Instruments;methods, Comparative MiP;environmental MiP, Developmental biology
Organism: Crustaceans, Annelids, Molluscs
Preparation: Intact organism
Regulation: Aerobic glycolysis, Oxygen kinetics Coupling state: ROUTINE