Approaches in organismic physiology focus mainly on the functional properties of individual organs (e.g. isolated perfused gills) or oxygen transport systems in marine ectotherms and their regulatory background, for example in acid – base and ion –regulatory systems. We apply several methods to determine the effects of different scenarios of environmental factors (temperature, hypercapnia) on whole animal physiological homeostasis and functional integrity. Various acclimation systems (from experimental chambers to mesocosms) are available to expose model organisms to experimental conditions during short (hours) and long term (months) incubations. Studies in whole organisms and isolated perfused organs are combined with those at cellular and molecular levels for a comprehensive analysis of functional integration
across levels of biological organisation.
Blood oxygen transport and metabolic rates:
Implantable oxygen and pH microsensors allow us to study ventilatory and circulatory oxygen transport. Miniaturized acoustic and laser Doppler systems are being used to quantify blood volume flow and cardiac dynamics, Tucker chambers allow assessment of respiratory protein oxygen saturation in different blood vessels. Several types of respirometers are available to study oxygen transport and metabolic rates at rest and during activity. In vivo NMR techniques enable us to study tissue oxygenation, blood flow and tissue energy status non-invasively (e.g. Frederich & Pörtner 2000, Bock et al. 2002, Mark et al. 2002, Sartoris et al. 2003, Lannig et al. 2004, Melzner et al. 2006, 2007).
Acid-base and ion regulation:
We measure intra- and extracellular pH, HCO3- and pCO2 using methods developed in our laboratory which enable us to determine animal acid – base status in response to applied stressors (e.g. Pörtner 1990, Pörtner et al., 1990, Finke et al. 1996, Mark et al. 2002, Pörtner et al. 2006). Disturbances in extracellular ion composition are being monitored using ion chromatography systems (e.g. Sartoris et al. 1998).