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L. E. Evans and W. C. Wagner

ABSTRACT

Plasma samples were collected from jugular, uterine and utero-ovarian veins during glucocorticoid induced parturition. Plasma oestrogens, corticosteroids and progesterone were determined by competitive protein binding methods.

Corticosteroids and progesterone began to decline within 8 to 10 h following DXMS treatment. Corticoids were only temporarily suppressed, while progesterone fell to minimum levels and remained low through calving.

At this stage of gestation (270 days) peripheral plasma progesterone was primarily of ovarian origin. Pre-treatment with HCG appeared to support progesterone production by the CL despite DXMS treatment in 2 of 6 cows. These 2 cows failed to calve within the expected 96 h after DXMS. Plasma oestrogens did not show significant increases until 24 h after DXMS treatment. Cows which responded to DXMS treatment (calved) had significantly higher oestrogen levels than those which did not respond. It was concluded that oestrogens probably play a permissive rather than an initiating role in parturition.

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S Muttukrishna, A Farouk, S Sharma, L Evans, N Groome, W Ledger and M Sathanandan

OBJECTIVE: Inhibin, activin and follistatin are glycoprotein hormones produced by the gonads. Recent studies have shown that inhibin B is the predominant form of inhibin in the circulation in men. The objective of this study was to investigate circulating levels of activin A and follistatin in disorders of spermatogenesis in men and their relationship with FSH and inhibin B. DESIGN AND METHOD: Serum from five different groups of men was prospectively collected and stored at -20 degrees C. The groups were men with: (i) proven fertility (controls) (n=20), (ii) primary testicular failure (n=15), (iii) obstructive azoospermia (n=10), (iv) oligospermia (n=10) and (v) miscellaneous sperm dysfunction (n=40). WHO criteria (1992) were used for semen characterisation. Serum concentrations of 'total' activin A, follistatin, FSH and inhibin B were measured using specific two-site enzyme immunoassays. RESULTS: Activin A levels were significantly lower than in the controls in the obstructive azoospermia group and higher in the miscellaneous sperm dysfunction group. Serum follistatin levels did not significantly vary in any group compared with the controls. Circulating levels of FSH were higher than in the controls in the primary testicular failure and obstructive azoospermic group. Levels of inhibin B were lower than in the controls in all disorders of spermatogenesis studied. CONCLUSION: This study demonstrates that activin A and follistatin are in the circulation in males and activin A levels are significantly lower in obstructive azoospermia and higher in miscellaneous sperm dysfunction than in controls. The mechanism involved in altering the levels of activin A in these conditions is not clear. However, high follistatin:activin A molar ratios (>2.5) in all groups suggests that all activin A in the circulation is bound to follistatin in males.

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William S. Evans, Rick J. Schiebinger, Donald L. Kaiser, Wallace C. Nunley Jr., D. Lynn Loriaux, Robert M. MacLeod and Michael O. Thorner

Abstract.

Conflicting data exist in the literature regarding serum adrenal androgen concentrations in hyperprolactinaemic states and the influence or lack thereof of dopaminergic drugs on the androgens. We carried out a prospective study on 7 hyperprolactinaemic women, none of whom had clinical features commonly associated with elevated androgens. Serum levels of prolactin (Prl), cortisol, androstenedione, dehydroepiandrosterone (DHA) and dehydroepiandrosterone sulphate (DHAS) were measured basally, at 3, 6, and 12 months during chronic bromocriptine therapy, and 2 months following withdrawal of the drug. Prior to bromocriptine therapy, and despite a mean serum Prl of 178 ng/ml, all values of cortisol, androstenedione and DHA were normal as were 6 of 7 DHAS values. During treatment with bromocriptine for 12 months, the mean Prl level dropped into the normal range, but levels of cortisol, androstenedione and DHA remained unchanged. DHAS was significantly lower at 12 months when compared to initial levels but was not significantly different at 3 and 6 months. No significant differences were observed in cortisol or androgens 2 months after termination of the bromocriptine compared to basal levels. A significant correlation was observed between cortisol and both androstenedione (P = 0.0042) and DHA (P = 0.0002) but not with DHAS. A significant correlation was found to exist between Prl and DHAS (P < 0.0001) but not with androstenedione or DHA. Thus, we found normal levels of serum adrenal androgens in 6 of 7 hyperprolactinaemic women, none of whom demonstrated clinical features of the polycystic ovary syndrome. These data suggest: 1) increased basal adrenal androgens in hyperprolactinaemia may not be as common as previously reported; 2) androstenedione and DHA do not correlate with Prl; 3) DHAS is correlated with Prl. Although it appears that DHAS and prolactin concentrations are related, the mechanism underlying this relationship remains uncertain.