Factors responsible for the decreased plasma concentration of prealbumin during acute inflammation and fasting in the rat.

The concentration of prealbumin in plasma and the elimination from plasma and whole body of intravenously injected 131I-labelled rat prealbumin were followed in normal rats and rats subjected to fasting or acute inflammation. During fasting and inflammation the concentration of prealbumin decreased to about 50% of the initial value. It was concluded from the radioactive tracer experiments that decreased synthesis was responsible for the decreased intravascular prealbumin mass in the fasting rats. In these rats the plasma volume also decreased. In the rats subjected to inflammation, both a decreased intravascular fraction and a decreased synthetic rate of prealbumin seemed to contribute to the decreased intravascular mass of prealbumin. The total catabolic rate was decreased in these conditions.