Publication Abstract
- Title
-
Use of a radioimmunoassay which detects C21 steroids with a 17,20b-dihydroxyl configuration to identify and measure steroids involved in final oocyte maturation in female plaice Pleuronectes platessa
- Publication Abstract
-
Use of a radioimmunoassay which detects C21 steroids with a 17,20β-dihydroxyl configuration to identify and measure steroids involved in final oocyte maturation in female plaice Pleuronectes platessa
A.P. Scott, R. Moses Inbaraj and E.L.M. Vermeirssen
A radioimmunoassay (RIA) has been developed to detect a range of C21 (pregnane) steroids with a 17,20β dihydroxyl (17,20β) configuration. In conjunction with reverse-phase high-performance liquid chromatography (HPLC), it identifies and quantifies the metabolites of 17,20β-dihydroxy- 4-pregnen-3-one, the putative "maturation-inducing steroid" in female plaice Pleuronectes platessa. Total levels of 17,20β metabolites which can be extracted from plasma or urine with diethyl ether (i.e., free steroids) are very low (< 3 ng/ml). However, total levels of 17,20β metabolites which can be released by solvolysis (i.e., sulphated steroids) are very high (up to 1 µg/ml in plasma and 10 µg/ml in urine). On HPLC, these sulphated metabolites have been identified (in order of abundance in plasma) as: 5β-pregnane- 3α,17,20β-triol, 5β-pregnane-3β,17,20β-triol, 17,20β-dihydroxy-4-pregnen -3-one, and 17,20β-dihydroxy-5β-pregnan-3-one. These steroids are absent from plasmas of fish which have not yet begun final oocyte maturation. The results support the hypothesis that 17,20β-dihydroxy-4-pregnen-3-one is the maturation-inducing steroid in plaice but that it is rapidly metabolised to render it inactive. The results also show that the '17,20β'-RIA, in combination with an overnight acid solvolysis procedure, is a useful procedure for monitoring the effects of exogenous factors (such as gonadotrophin injections) on final oocyte maturation in female plaice.
Reference:
A.P. Scott, R. Moses Inbaraj and E.L.M. Vermeirssen, 1997. Use of a radioimmunoassay which detects C21 steroids with a 17,20b-dihydroxyl configuration to identify and measure steroids involved in final oocyte maturation in female plaice Pleuronectes platessa. General and Comparative Endocrinology, 105: 62-70.
- Publication Internet Address of the Data
- Publication Authors
-
A.P. Scott*, R. Moses Inbaraj and E.L.M. Vermeirssen*
- Publication Date
- January 1997
- Publication Reference
-
General and Comparative Endocrinology, 105: 62-70
- Publication DOI: https://doi.org/
