In vivo and in vitro evidence for the biosynthesis of testosterone in the telencephalon of the female frog.

Neurons and glial cells are capable of synthesizing various steroid hormones, but biosynthesis of testosterone in the CNS has never been reported. The aim of the present study was to demonstrate the synthesis of testosterone in the frog brain. The presence of 17beta-hydroxysteroid dehydrogenase (17beta-HSD)-like immunoreactivity was detected in a population of glial cells located in the telencephalon.

Localization of 17beta-hydroxysteroid dehydrogenase and characterization of testosterone in the brain of the male frog.

Several enzymes involved in the formation of steroids of the pregnene and pregnane series have been identified in the brain, but the biosynthesis of testosterone has never been reported in the central nervous system. In the present study, we have investigated the distribution and bioactivity of 17beta-hydroxysteroid dehydrogenase (17beta-HSD) (EC 1.1.

Desorption of ions from locust tissues. III. Study of a metabolite of A-destruxin using fast-atom bombardment linked-scan mass spectrometry.

The process of the detoxification of A-destruxin into a polar linear peptide in vivo in Locusta migratoria has been demonstrated using both high performance liquid chromatography and negative-ion fast-atom bombardment mass spectrometry. The final structure of the metabolite, after synthesis and comparison of retention time with the component in the crude biological mixture, was elucidated by positive-ion fast-atom bombardment linked-scan mass spectrometry. Diagnostic fragment ions produced by collision-induced dissociation are discussed.

Characterization of cyclodepsipeptide-glutathionyl conjugates by negative-ion fast-atom bombardment linked-scan mass spectrometry.

A cyclodepsipeptide-glutathionyl conjugate has been analysed for the first time using negative-ion fast-atom bombardment linked-scan mass spectroscopy. Fragment anions produced by collision-induced dissociation are discussed.