title: Absence of measurable 2-hydroxyestrone in the rat brain: evidence for rapid turnover.
abstract: The free 2-hydroxyestrone content of female rat brains was measured by two independent methods, including a direct radioimmunoassay and enzymatic conversion to stable O-methylated derivatives followed by a specific radioimmunoassay for the latter. The sensitivities of the two procedures were 10 pg and 5 pg respectively and the recoveries were greater than 85%. Neither assay method was able to detect any measurable endogenous 2-hydroxyestrone in the female rat brain at any stage of the ovulatory cycle. It is suggested that a high turnover rate of 2-hydroxyestrogens in the rat brain precludes the accumulation of detectable quantities of these metabolites in central tissues.
mesh_terms: D000818:Animals; D001921:Brain / Q000378:metabolism; D001923:Brain Chemistry; D004970:Estrone / Q000031:analogs & derivatives*; D005260:Female; D006894:Hydroxyestrones / Q000378:metabolism*; D008745:Methylation; D011863:Radioimmunoassay; D051381:Rats
chemical_list: D006894:Hydroxyestrones; D004970:Estrone