Csilla Jakab

Comparative analysis of plasma 17-hydroxyprogesterone and cortisol responses to ACTH in patients with various adrenal tumors before and after unilateral adrenalectomy

Patients with non-hyperfunctioning adrenal adenomas often have an increased plasma 17-hydroxyprogesterone response to ACTH stimulation. The effects of adrenal surgery on this abnormality have rarely been investigated. One hundred and sixty-one patients with unilateral adrenal tumors (non-hyperfunctioning adenomas, 78; cortisol-producing adenomas, 8; aldosteroneproducing adenomas, 37; adrenal cysts, 12; pheochromocytomas, 26) were studied. Patients before and after adrenal surgery as well as 60 healthy subjects underwent an ACTH stimulation test using 2 mg synthetic ACTH1-24 (Cortrosyn Depot, Organon). Basal and ACTH-stimulated plasma 17- hydroxyprogesterone and cortisol concentrations are reported. Before adrenal surgery, the basal plasma 17-hydroxyprogesterone concentrations were normal in patients with all types of tumors. However, the ACTH-stimulated plasma 17-hydroxyprogesterone levels were abnormally increased in 53% and 31% of patients with non-hyperfunctioning adenomas and aldosterone-producing adenomas, respectively. In addition, a few patients with adrenal cysts and pheochromocytomas also showed an increased ACTH-stimulated 17- hydroxyprogesterone response. After unilateral adrenalectomy, this hormonal abnormality disappeared in most, although not all patients with adrenal tumors. In patients with non-hyperfunctioning adrenal tumors, ACTH-stimulated plasma 17-hydroxyprogesterone and cortisol concentrations significantly correlated with the size of the tumors. These results firmly indicate that the tumoral mass itself may be responsible for the increased plasma 17-hydroxyprogesterone and cortisol responses after ACTH stimulation in patients with non-hyperfunctioning and hyperfunctioning adrenal adenomas.

Leptin Inhibits Cortisol and Corticosterone Secretion in Pathologic Human Adrenocortical Cells

Regulation of adrenal corticosteroid secretion by leptin may involve interactions at multiple levels of the hypothalamic-pituitary-adrenal axis. To investigate the possible direct effects of leptin on corticosteroid secretion of human adrenocortical adenomas, cells from adrenocortical adenomas causing primary aldosteronism (n = 1) and Cushings syndrome (n = 1), as well as cells from nonhyperfunctioning adrenocortical adenomas (n = 5) were isolated and incubated for 2 h with human recombinant leptin (1–1000 ng/ml) in the presence and absence of adrenocorticotrop hormone (ACTH), then cortisol, corticosterone and aldosterone concentrations in incubating media were determined using radioimmunoassays. It was found that leptin effectively and dose-dependently inhibited basal and ACTH-stimulated cortisol and corticosterone secretion in the three types of human adrenocortical adenoma cells. The inhibiting effect of basal corticosterone secretion was detectable in the presence of leptin concentration as low as 1 ng/ml, with decreases of corticosterone secretion to 34 ± 4%, 57 ± 11% and 79 ± 9% in Cushings syndrome, primary aldosteronism, and nonhyperfunctioning adrenocortical adenoma cells, respectively. The inhibition of basal cortisol secretion in the presence of low concentration of leptin was less prominent, but 10 ng/ml leptin significantly diminished basal cortisol secretion to 81 <6 9% in adrenocortical adenoma cells from Cushings syndrome, to 68 ± 6% in4 adenoma cells from primary aldosteronism, and to 83 ± 8% in cells from nonhyperfunctioning adenomas. The inhibition of ACTH-stimulated cortisol and corticosterone secretion by leptin was similar to those found in cells without ACTH stimulation. By contrast, leptin even at 1000 ng/ml concentration exerted no clear effect on basal and ACTH-stimulated aldosterone secretion in cells from primary aldosteronism and in those nonhyperfunctioning adenoma cells in which aldosterone secretion was detectable. These results indicate that leptin is a potent inhibitor of cortisol and corticosterone secretion in human adenomatous adrenocortical cells. The inhibition of these corticosteroids by leptin may represent a potentially important interaction that exists between leptin and the hypothalamic-pituitary-adrenal axis.

Rapid re-enlargement of a macroprolactinoma after initial shrinkage in a young woman treated with bromocriptine

We report the case of a macroprolactinoma in a 32-year-old woman, who presented with secondary amenorrhea, galactorrhea, increased plasma prolactin level (3259 ng/ml), headache and bi-temporal visual field defect. Magnetic resonance imaging showed a large pituitary tumor. The patient responded well to bromocriptine (7.5 mg/day) with improvement of clinical symptoms and normalization of plasma prolactin within a few weeks. After 4 months of treatment, tumor size was also reduced markedly. During continued treatment at the same dose of bromocriptine the plasma prolactin level remained normal, but after 8 months of treatment the patient suddenly complained of worsening of her visual fields, and magnetic resonance imaging indicated re-enlargement of the tumor. Bromocriptine was discontinued and transsphenoidal pituitary surgery was performed. After surgery the visual field defect improved, but postoperative plasma prolactin level (1104 ng/ml) and magnetic resonance imaging indicated a residual tumor. Postoperative treatment with quinagolide (0.15 mg/day) resulted in disappearance of all clinical symptoms, normalization of prolactin level and a reduction in size of the residual tumor. This case demonstrates that a dissociation of the inhibitory effect of bromocriptine on tumor size and prolactin level may rarely develop during the course of drug treatment in a patient with macroprolactinoma.