A rapid method for the measurement of the oxoreductase activity of 11beta-hydroxysteroid dehydrogenase in granulosa-lutein cells from patients undergoing in-vitro fertilization.

摘要: The presence of 11beta-hydroxysteroid dehydrogenase (11beta-HSD; EC1.1.1.146), the enzyme responsible for interconversion cortisol and cortisone, in granulosa-lutein (GL) cells is associated with a poor outcome in-vitro fertilization (IVF). We have developed simple method assessing reductase component 11beta-HSD these which sufficiently rapid to provide data on enzyme's activity prior embryo replacement. Cells were pooled from follicular aspirates challenged cortisone within 2 h aspiration. Cortisol secretion was then measured by radioimmunoassay. Conversion linear up 3 completely inhibited glycyrrhetinic acid, specific inhibitor. Initial velocity rates determined eight concentrations (range 0.1-8 micromol/l), apparent Km calculated (1.6 +/- 0.4 micromol/l). There no evidence substrate/product inhibition conversion <2% all experiments. In subsequent work, (6 micromol/l) h. immediately following purification produced varying amounts 25-150 nmol/pooled follicles each patient, n = 10 patients), while basal outputs <6 nmol/l. Enzyme also examined per follicle basis individual patients found vary considerably (e.g. 19, 53 36 nmol/l cortisol/1000 cells, three follicles). Having established 11beta-reductase GL we performed small prospective study series 20 examining 110 follicles. 11Beta-reductase varied greatly patient ranging <0.024-0.57 nmol cortisol/microg DNA but at present low numbers preclude meaningful correlation between pregnancy rate. summary, simple, (<8 h) assay detecting isolated or This procedure quick aid choice