Pituitary steroids in two teleost species: Immunohistological and biochemical studies

• Published in: General and comparative endocrinology Vol. 76; no. 1; pp. 63 - 72
• Main Authors: Peute, J., Schulz, R., Glazenburg, K., Lambert, J.G.D., Blüm, V.
• Format: Journal Article
• Language: English
• Published: San Diego, CA Elsevier Inc 01.10.1989; Elsevier
• Subjects: Androstenedione - analogs & derivatives; Androstenedione - analysis; Androstenedione - immunology; Androstenedione - metabolism; Animals; Antigen-Antibody Reactions; Biological and medical sciences; Catfishes - metabolism; Clarias gariepinus; Estradiol - analysis; Estradiol - immunology; Estradiol - metabolism; Female; Freshwater; Fundamental and applied biological sciences. Psychology; Gas Chromatography-Mass Spectrometry; Gonadotropins, Pituitary - immunology; Gonadotropins, Pituitary - metabolism; Immunohistochemistry; Male; Oncorhynchus mykiss; Pituitary Gland - analysis; Pituitary Gland - cytology; Pituitary Gland - metabolism; Radioimmunoassay; Salmonidae - metabolism; Steroid hormones. Cholecalciferol derivatives; Testosterone - analysis; Testosterone - immunology; Testosterone - metabolism; Trout - metabolism; Vertebrates: endocrinology; Immunohistochemistry; Endocrine gland; Steroid hormone; Interspecific comparison; Clarias gariepinus; Gonadotropin; Blood plasma; Freshwater environment; Gas chromatography; Vertebrata; Castration; Gonadotropic cell; Radioimmunoassay; Pisces; Pituitary gland; Salmo gairdneri; Localization; Mass spectrometry
• ISSN: 0016-6480; 1095-6840
• DOI: 10.1016/0016-6480(89)90033-6

Antisera raised against steroid hormones [estradiol-17β (E 2), testosterone (T), 11β-hydroxyandrostenedione (OHA)] were used to localize immunoreactive material in fixed and paraffin-embedded pituitaries of the African catfish and the rainbow trout. Organic extracts of pituitary homogenates were analyzed for steroid hormones by radioimmunoassay and gas chromatography-mass spectrometry (E 2 in female catfish only). With the exception of an E 2-positive cell type in the catfish neurointermediate lobe, steroid immunoreactivity was found to be restricted to the cytoplasm of adenohypophyseal cells, which were also labeled after incubation with catfish α,β-gonadotropin and salmon gonadotropin antisera, respectively. Steroid levels determined by radioimmunoassay in the catfish ranged between 85 and 628 pg/pituitary, while lower levels (2–8 pg/pituitary) were found in the rainbow trout. E 2 was identified by gas chromatography-mass spectrometry at a level of 84 pg/pituitary. The observation that immunolabeling after steroid antiserum incubation is confined mainly to gonadotrops provides morphological evidence for direct steroid effects on this particular cell type.