In vitro secretion of ecdysteroids by Y-organs of the crayfish,Procambarus clarkii

It was demonstrated that excised Y-organs of the crayfish,Procambarus clarkii, synthesize in vitro 3-dehydroecdysone (3-DHE) as the major product, together with small amounts of ecdysone. Both were identified by immunological and spectroscopic methods. The increase of ecdysteroidogenesis in the Y-organs was accompanied by an increase of the major free ecdysteroid, 20-hydroxyecdysone, in the hemolymph. This suggests a physiological role of 3-DHE, the details of which are still to be elucidated.