High pressure liquid chromatographic systems capable of resolving at least 28 known and potential metabolites of 17@-hydroxy-4-androsten-3-one (testosterone) and 4-androstene-3,17-dione (androstenedione) were used to quantitatively assess the metabolism of the two steroids in monooxygenase systems reconstituted with five purified rat liver cytochrome P-450 isozymes. Cytochromes P-450a, -b, -c, ...

androstenedione may be similar. Unfortunately, the majority of publications to date that include data on the disposition of androstenedione do not detail changes in the AUCs of either androstenedione or testosterone as a measure of exposure. Assuming there is no large difference in steroid metabolic pathways between genders, then the difference in plasma androstenedione profiles observed may po...

INTRODUCTION Congenital adrenal hyperplasia (CAH) or adrenogenital syndrome is the most common cause of female ambiguous genitalia. Management of such patients involves medical treatment using glucocorticoids such as hydrocortisone, prednisone or dexamethasone. Monitoring is done by measurement of 17-hydroxyprogesterone (17-OHP) or androstenedione in serum, plasma or saliva. The aim of this stu...

Implants ofprogesterone on the day ofdioestrus II in the hamster induced on the following day an increase in circulating levels of progesterone (6\m=.\0\m=+-\0\m=.\7ng/ml, N = 8; sesame oil controls, <0.5 ng/ml, N = 6) and a decline in serum levels of LH (5\m=.\3\m=+-\0\m=.\4ng/ml; controls 12 \m=+-\2 ng/ml) and oestradiol (10 \m=+-\2 pg/ml ; controls 69 \m=+-\5 pg/ml). The production of andros...

Minces of testes from mature and immature guinea pigs were incubated with [(14)C]androstenedione. Other portions of the same testes were simultaneously incubated with [(14)C]testosterone. Under steady-state conditions, the predominant steroid was [(14)C]androstenedione in the presence of tissue from young animals and [(14)C]testosterone in that from mature animals, irrespective of the compound ...

Partial neutralization of bone morphogenetic protein 15 (BMP15) bioactivity by immunization is known to increase ovulation rate in sheep. However, it remains uncertain whether BMP15 vaccination would be a suitable procedure for increasing lambing rate. The aim of this study was to compare the efficacy of a BMP15 vaccination treatment on lamb production to that of commercially-available androste...

The interconversion and extraction of testosterone and androstenedione across and within different tissues or areas have been studied by the constant infusion technique. The results were calculated using the (3)H/(14)C ratios and radioactive concentrations of testosterone and androstenedione obtained from afferent and efferent blood and tissues at equilibrium. In each tissue studied, the interc...

BACKGROUND Secreting interstitial cell (Leydig cell) tumors are rare. In adults, the clinical picture and steroid levels are variable. CASE PRESENTATION This paper presents a case of left testicular tumor, showing azoospermia with normal serum level of total testosterone, collapsed FSH and LH, and high delta4 androstenedione. Histopathological investigation revealed a Leydig cell tumor. TESE ...

The steroid hormone androstenedione profoundly influences the development and expression of sexual and aggressive behavior. The neural basis of these effects are, however, poorly understood. In this study we evaluated androstenedione's ability to maintain vasopressin peptide levels in the gonadal steroid-responsive vasopressin cells of the bed nucleus of the stria terminalis and the centromedia...