[Involvement of 3-dehydroecdysteroids in the ecdysone biosynthetic pathway in Locusta migratoria, in vitro].
Prothoracic glands of the locus, Locusta migratoria, incubated in vitro converted tritiated 3-dehydrocetodiol (22,23,24,25 3H4-14 alpha-hydroxy-5 beta-cholest-7-en-3,6-dione) into ecdysteroids and 3-dehydroecdysteroids as far as the final products of the two series, ecdysone and 3-dehydroecdysone. In the two series, the different compounds are formed in the same quantities, except for 2,22-desoxy-products, the nature of which could not have been determined. Converted 3-dehydroecdysone issued from 3-dehydrocetodiol is transformed into ecdysone after several hours incubation with Locusta last instar larvae hemolymph. Till now is has been impossible to determine if the reduction of 3-dehydroecdysteroids took place into the prothoracic glands or in the incubation medium. In no case is 3-dehydrocetodiol converted into cetodiol. Conversion rates of the different compounds, either issued from cetodiol or from 3-dehydrocetodiol as precursors, are of same importance, so that a weak specificity of the hydroxylation enzymes must be considered.
Roussel
J P
JP
Laboratoire de Biologie Générale, URA CNRS n. 672, Université Louis Pasteur, Strasbourg, France.
D000818:Animals; D004440:Ecdysone / Q000096:biosynthesis*; D026461:Ecdysteroids; D004702:Endocrine Glands / Q000502:physiology*; D006110:Grasshoppers / Q000378:metabolism*; D066298:In Vitro Techniques; D007447:Invertebrate Hormones / Q000502:physiology*
D026461:Ecdysteroids; D007447:Invertebrate Hormones; D004440:Ecdysone