Determination of Δ5 3β-hydroxysteroid dehydrogenase activity in intact isolated rat Leydig cells |
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| Authors: | G F Paz J S D Winter F T Reyes C Faiman |
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| Institution: | Departments of Physiology, Paediatrics, Obstetrics &Gynaecology and Medicine, University of Manitoba, Winnipeg, Manitoba R3E OZ3 Canada |
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| Abstract: | A method for the determination of Δ5 3β-hydroxysteroid dehydrogenaseisomerase (3β-HSD) activity in intact isolated Leydig cells was established. This method utilizes the conversion of 7-3H]dehydroepiandrosterone (1.04 μmole) to androstenedione and expresses the activity of the enzyme as μmoles of androstenedione produced/μg DNA/h. The reaction is limited to 0.5-4 μg DNA of Leydig cells/ml (equivalent to 0.1-0.8 million of Levdig cells/ml) and to 1 h of incubation at 34°C. The 3β-HSD activity of 44 suspensions of Leydig cells isolated from adult rats was found to be 1.13 pL 0.03 (SE) μmoles/μg DNA/h. This new method for direct measurement of 3β-HSD activity in intact Leydig cells was found to be rapid, easy to perform and highly reproducible. |
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| Keywords: | isolated Leydig cells 3β-HSD |
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