Albumins stabilize prostaglandin I2.

We monitored the chemical stability of prostaglandin I2 in the presence of different plasma proteins. PGI2 hydrolyzes by first order reaction kinetics, dependent on the albumin concentration in aqueous buffers. Chemical analysis shows that vertebrate albumins prolong the half-life of prostaglandin I2. The degree of stabilization varies quantitatively among different species. The results indicate that prostaglandin I2 may persist in its active form longer than previously supposed in some experimental conditions.