[Age-related characteristics of the prostaglandin system in certain organs]

The biosynthesis of PGE2, PGF2, PGI2 alpha from 14C-arachidonic acid and the catabolism of 3H--PGF1 alpha and 3H--PGE2 were studied in kidney, aorta and lung homogenates of young (1.5 months) and adult (3.5 months) Wistar rats. An increased synthesis of PGE2 was found in aorta and kidneys and PGI2 in lungs and heart of young rats. PGE2 alpha synthesis in kidneys and aorta underwent no alteration with age. The 3H--PGE2 catabolism in lungs and kidneys was more intensive in young rats whereas the 3H--PGF1 alpha degradation did not differ in various age groups but somewhat decreased with age in lungs. Close correlation was found between the biosynthetic coefficients PGF/PPE in kidneys and the AP level in young rats. A reciprocal interrelationship was found between the biosynthetic and the catabolic coefficients PGF/PGE in kidney, aorta and lungs of young and adult rats. This results in a balance of synthesis and catabolism of prostaglandins in kidney and lungs which prevents release of great quantities of prostaglandins from the sites of their synthesis into the systemic circulation. In other words, the processes of biosynthesis and catabolism of prostaglandins in the organism maintain a constant level of these biologically active substances in the systemic circulation.