The effect of temperature on the Donnan potentials in biological polyelectrolyte gels: cornea and striated muscle.

The effect of temperature on the fixed electric charge in biological polyelectrolyte gels was studied between 10 and 35 degrees C using the Donnan microelectrode technique. Two tissues; cornea and striated muscle were used. In cornea, there is a gentle and uniform decrease in fixed charge over the temperature range. In rigor muscle, there is a dramatic step-function decrease in charge at around 28 degrees C. There is a charge decrease in relaxed muscle at around the same temperature, but the step function is less distinct. The significance of these different experimental relationships is discussed in relation to the Saroff model for ion binding to proteins, linked to the possible disordering effects of excess electric charge. The diverse effects in these systems are important for the physiological functions of the different tissues.