ISOLATION AND PARTIAL CHARACTERIZATION OF TAMMAR WALLABY LUTEINIZING-HORMONE AND DEVELOPMENT OF A RADIOIMMUNOASSAY

Tammar wallaby (Macropus eugenii) luteinizing hormone (LH) was purifie d from pituitaries collected from wild and captive populations by salt sequential precipitation, ion exchange chromatography and gel filtrat ion. Pituitary tissue (5 g) yielded 1.8 mg of purified wallaby luteini zing hormone (ME-14B), as verified by sodium dodecyl sulfate polyacryl amide gel electrophoresis (SDS-PAGE). A heterologous radioimmunoassay has been developed for measurement of LH in plasma of marsupials using a monoclonal antibody raised against bovine LH (518B7). This assay sy stem was able to measure basal LH concentrations in male and female ta mmars and detected a significant rise in plasma LH in response to oest radiol benzoate in female tammars and luteinizing hormone-releasing ho rmone (LHRH) in males. Parallel dose-response curves were also obtaine d from pituitary extracts from four other species of marsupial (brusht ail possum, Trichosurus vulpecula; brown antechinus, Antechinus stuart ii; kowari, Dasyuroides byrnei; and Eastern pygmy possum, Cercartetus nanus) in this assay, which suggests its usefulness in the measurement of LH in other marsupial species.