CGS-16949A is a new orally active nonsteroidal aromatase inhibitor which is more than 100-fold more potent than aminoglutethimide. This compound is an imidazole derivative, and therefore, its possible effect on cytochrome P-450-dependent enzyme activities in the adrenal gland was evaluated. In vitro investigations with dispersed normal and hyperplastic human adrenocortical cells showed that CGS-16949A at 10(-7)-10(-6) M is a potent 11 beta-hydroxylase inhibitor, which inhibits ACTH-stimulated cortisol release to a similar extent as an equimolar concentration of metyrapone (IC50 for both compounds, 10(-7)-5 X 10(-7) M). Etomidate was a more potent 11 beta-hydroxylase inhibitor (IC50, approximately 10(-8) M), while 10(-7)-10(-6) M ketoconazole caused (via 17 alpha-hydroxylase inhibition) a similar inhibition of cortisol release as 10(-7) M CGS-16949A (IC50, 10(-7)-5 X 10(-7) M). The 11 beta-hydroxylase inhibition by CGS-16949A was accompanied by a dose-dependent increase in the release of precursor steroids by the adrenocortical cells in vitro, including deoxycortisol, 17-hydroxyprogesterone, and androstenedione. Aldosterone release was suppressed 50% by 10(-9) M CGS-16949A, while the IC50 for cortisol in the same cells was 10(-7) M. Aldosterone release by the dispersed adenoma cells obtained from a patient with primary aldosteronism was also significantly suppressed by CGS-16949A. We concluded that 1) the new nonsteroidal aromatase inhibitor CGS 16949A is an inhibitor of 11 beta-hydroxylase which is equipotent to metyrapone. At present it is unclear whether the compound at the dose that causes complete aromatase inhibition in vivo also affects stress-induced cortisol release in man. 2) CGS-16949A exerts a very potent inhibitory effect on normal aldosterone release (IC50, 10(-9) M) and on tumorous aldosterone secretion. CGS-16949A might, therefore, be a drug that can be used in the treatment of primary hyperaldosteronism.

Suramin, a polyanionic compound which has been used in the treatment of trypanosomiasis and oncocerciasis, has recently been used in treatment of AIDS, while preliminary success has been reported in the treatment of cancer. However, suramin also causes adrenal insufficiency. The present study was undertaken in order to investigate the effect of suramin on ACTH-stimulated steroid production by dispersed rat adrenal cells. It was shown that suramin at concentrations of 10(-4)-10(-3) M inhibits ACTH-stimulated corticosterone release in a dose-dependent manner IC50 (2.10(-4) M). In addition, suramin caused a parallel decrease in ACTH-stimulated pregnenolone, progesterone and corticosterone release, suggesting that suramin does not affect corticosteroidogenesis via an inhibition of its regulatory enzymes. Suramin at 10(-4) M did not inhibit cholera toxin (10 mg/l)-, forskolin (5 microM)- and dbcAMP (5 mM)-stimulated corticosterone release, while cholera toxin completely overcame the inhibitory effects of very high concentrations of suramin (up till 10(-3) M), on ACTH-stimulated corticosterone release. Finally, chromatographic studies with a matrex gel showed that suramin directly interacted with the ACTH molecule. In conclusion, suramin at "therapeutic" concentrations (10(-4) M and higher) prevents ACTH-stimulated corticosterone release probably via a direct interaction with the ACTH molecule.

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Chronic administration of corticosteroids results in a suppression of the hypothalamo-pituitary-adrenocortical (HPA) axis. The time course of the recovery of the HPA axis depends on the dose and duration of corticosteroid administration. We investigated the recovery of the HPA axis after 14 days of prednisolone administration to rats at a dose of 2.0 mg/rat/day via the drinking water (188 µmol/l). The in vitro corticosterone production by dispersed adrenal cells in response to increasing concentrations of ACTH had recovered 3 days after stopping prednisolone administration. In parallel the initially suppressed plasma corticosterone concentrations had recovered after 3 days, while the pituitary ACTH content had recovered after 5 days. We investigated the possibility to enhance the speed of the recovery of the HPA axis by the simultaneous administration of two drugs with known CRF-stimulating activity via the drinking water. Caffeine in a dose of 100 mg/kg body weight enhanced the recovery of the prednisolone-suppressed HPA axis significantly. One day after the end of prednisolone administration a significant increase in the adrenal weight, in the corticosterone production by dispersed adrenal cells, as well as in the plasma corticosterone concentrations, and in the pituitary ACTH content was observed in the caffeine-treated rats. Chlorimipramine (20 mg/kg body weight), on the other hand, did not influence the prednisolone-mediated suppression of the HPA axis. It is concluded that: (1) simultaneous administration of caffeine enhances the speed of the recovery of the HPA axis after prednisolone administration as evidenced by the full recovery or tendency to recovery of all the investigated components of the HPA axis; (2) chlorimipramine, however, did not influence the suppression of the HPA axis, when administered simultaneously with prednisolone.

SummaryKallmann syndrome (KS) is a form of hypogonadotropic hypogonadism in combination with a defect in sense of smell, due to abnormal migration of gonadotropin-releasing hormone-producing neurons. We report a case of a 17-year-old Tunisian male who presented with eunuchoid body proportions, absence of facial, axillary and pubic hair, micropenis and surgically corrected cryptorchidism. Associated findings included anosmia. Karyotype was 46XY and hormonal measurement hypogonadotropic hypogonadism. MRI of the brain showed bilateral agenesis of the olfactory bulbs and 3.5 mm pituitary microadenoma. Hormonal assays showed no evidence of pituitary hypersecretion.Learning points:The main clinical characteristics of KS include hypogonadotropic hypogonadism and anosmia or hyposmia.MRI, as a non-irradiating technique, should be the first radiological step for investigating the pituitary gland as well as abnormalities of the ethmoid, olfactory bulbs and tracts in KS.KS may include anterior pituitary hypoplasia or an empty sella syndrome. The originality of our case is that a microadenoma also may be encountered in KS. Hormonal assessment indicated the microadenoma was non-functioning. This emphasizes the importance of visualizing the pituitary region in KS patients to assess for hypoplastic pituitary malformations or adenomas.