Identification of testosterone and progesterone in hemolymph of larvae of the fleshfly Sarcophaga bullata

Abstract

Testosterone- and progesterone-like substances were detected by radioimmunoassay (RIA) in chromatographed extracts of hemolymph from larvae of Sarcophaga bullata (S.B.). Gas chromatographic (GC) analysis after heptafluorobutyric acid (HFBA) derivation of hemolymph extracts, purified by paper and silica gel column chromatography, showed a peak in the GC recordings with the same retention time as the HFBA derivative of pure testosterone. A testosterone concentration of 92 ng/100 ml hemolymph was found by GC; the concentration of progesterone, calculated on the basis of the RIA, was about two times higher. After preparing the o-pentafluorobenzyloxime (OPFB)-heptafluorobutyryl ester (HFB) derivatives of the hemolymph extracts, negative ion chemical ionization capillary gas chromatography-mass spectrometry ( NCI GC-MS ) proved that hemolymph of larvae of the fleshfly Sarcophaga bullata indeed contains testosterone and progesterone. Several metabolites and precursors of the latter compounds could also be detected during the NCI GC-MS ) analyses. Estrogens could not be traced by any of the methods we used. This is the first time that these steroids have been identified in insect hemolymph. These results add interesting perspectives for comparative endocrinology.