Isolated Rabbit Jejunum Research Articles

THE BIOLOGICAL ACTIVITY OF PROSTAGLANDIN E1, E2 AND E3.

The prostaglandin compounds possessing a cyclopentanone structure and 1 2 and 3 double bonds respectively were tested in the isolated rabbit jejunum the guinea pig ileum and on the rabbits blood pressure. On the rabbit jejunum relative activity was highest for PGE2 and lowest for PGE2. In the rabbit blood pressure PGE1 was more active than PGE2. Activity ratio PGE1:PGE3 was about the same for the two test preparations. That of PGE1:PGE2 differed by a factor of 4 to 10 on the two tests. This difference may be used for calculating approximate proportions of PGE2 in a mixture of the 3 compounds. Comparison with the biological unit used previously revealed that when tested on the rabbit jejunum 1 mcg PGE1 was equivalent to 0.2-0.25 units of a total extract of prostaglandin from human seminal fluid. On the rabbits blood pressure the equivalent was 0.3 to 0.5 units while on the guinea pig ileum the corresponding value was 1.6 units.