Localization of aromatase in the brain of the male African catfish, Clarias gariepinus (Burchell), by microdissection and biochemical identification

• Published in: Journal of comparative neurology (1911) Vol. 258; no. 3; p. 368
• Main Authors: Timmers, R J, Lambert, J G, Peute, J, Vullings, H G, van Oordt, P G
• Format: Journal Article
• Language: English
• Published: United States 15.04.1987
• Subjects: Animals; Aromatase - metabolism; Brain - enzymology; Brain - physiology; Catfishes - metabolism; Estrogens - physiology; Species Specificity
• ISSN: 0021-9967
• DOI: 10.1002/cne.902580305

Aromatase activity was determined in small discrete areas of the brain of the African catfish, Clarias gariepinus, by a radiometric assay. The fore- and midbrain were divided into eighteen 500-microns transverse sections. From these sections several punches (0.3 mg of tissue) were taken and incubated with [19-3H]-androstenedione. The aromatase activity, calculated from the release of tritium label during aromatization, is expressed in pmol mg-1 tissue hour-1. The highest activity (3.7 pmol) was detected in the preoptic region. The more caudally located area tuberalis, including the nucleus lateralis tuberis and the nucleus recessus lateralis, also showed a relatively high activity (2.5 pmol). A similar activity was found in the most rostral part of the telencephalon and the dorsal parts of the mesencephalon, i.e., the tectum opticum and torus semicircularis (2.3 pmol). A moderate aromatase activity was observed in remaining parts of the brain, except the cerebellum and hindbrain, in which aromatase activity was hardly detectable (0.1-0.3 pmol). It is concluded that a high aromatase activity is present in regions known to be involved in the regulation of reproduction. Since both the torus semicircularis and the tectum opticum display a high aromatase activity, it is suggested that also these structures are involved in reproductive processes.