Ecdysteroids in relation to the molt cycle of the American lobster, Homarus americanus. I. Hemolymph titers and metabolites.

摘要: Abstract Hemolymph ecdysteroid (Ecd) titers were measured using radioimmunoassay (RIA) during the molt cycle of American lobster, Homarus americanus . Individual animals showed small, transitory rises Ecds which increased in magnitude with onset premolt and culminated a large peak at morphological stages D 2 -D 3 1 Male lobsters had significant postmolt peaks late that remained high until ecdysis. In females, absent reached basal levels before At least seven different Ecd metabolites identified by high-performance liquid chromatography-RIA analyses. High polarity products (HP) most abundant virtually every stage. Titers HP significantly higher males postmolt-early intermolt premolt. Levels 20-hydroxyecdysone (20E) equivalent both sexes correlated changes associated Evidence was also obtained for presence ecdysone, ponasterone A, other as yet unidentified metabolites. The pattern hemolymph supports data indicative 20E major molting hormone. Metabolism is primarily toward more polar compounds, including conjugates.