Abstract. 5α-reductase activity was investigated in scalp hair roots in 5 patients with 5α-reductase deficiency and in 10 normal volunteers (5 men and 5 women) who served as controls. Metabolism of [3H]testosterone and [3H]epitestosterone was measured under standardized conditions in 1–4 growing (anagen) hair roots. When the mean values of the 5α-reduced metabolites from testosterone (androstanedione and dihydrotestosterone) or from epitestosterone (epidihydrotestosterone) were compared in both groups, similar values were observed. However, since most of the hair roots were incubated singly, it could be demonstrated that in two patients 20 respectively 24% of the hair roots showed neither dihydrotestosterone nor epidihydrotestestosterone formation. This did not influence the mean values determined for the whole group perceptibly. Our results support the concept that 5α-reductase deficiency is a genetically heterogenous disorder by demonstrating that the enzyme defect is variously expressed in hair roots of affected individuals.
J. André Schmidt and Hans-Udo Schweikert
Monika Bals-Pratsch, Hans-Udo Schweikert and Eberhard Nieschlag
Three brothers with congenital transposition of the penis, scrotal hypospadias, bifid scrotum, and bilateral undescended testes are described. Further signs of incomplete virilization, but no gynecomastia were seen. LH and FSH were elevated, whereas testosterone levels were reduced or in the normal range. Serum concentrations of 17-hydroxyprogesterone, dehydroepiandrosterone, androstenedione, 5α-dihydrotestosterone and estradiol measured in two affected brothers were in the normal range. Fibroblasts from scrotal skin biopsies performed in two patients showed normal 5α-reductase activity (419 and 214 pmol · (mg protein)−1 · h−1; normal >1), whereas androgen receptors had reduced maximal binding capacity (Bmax 4 and 14 fmol · (mg protein)−1; normal ≥ 18) and an increased equilibrium dissociation constant (0.7 and 1.26 nmol/l; normal 0.2±0.08) indicating a quantitative and qualitative androgen receptor defect. These patients represent a further variant of androgen insensitivity.
Axel Overlack, Miyoko Higuchi, Rainer Kolloch, Hans-Michael Müller, Klaus O. Stumpe and Hans-Udo Schweikert
Abstract. It has been suggested that the renal kallikreinkinin system is dependent on mineralocorticoid activity. This hypothesis was studied in a patient with cyclic Cushing's syndrome combined with cortisol suppressible, dexamethasone non-suppressible ACTH secretion. The 24-h urinary excretions of sodium, potassium, cortisol, active and inactive kallikrein, aldosterone, and prostaglandin E2 (PGE2) were studied during normal and excessive cortisol secretion and after bilateral adrenalectomy. Kallikrein, PGE2 and potassium rose during cortisol overproduction while aldosterone and sodium decreased. Kallikrein, PGE and potassium were positively related to cortisol excretion, whereas urinary aldosterone and sodium showed a negative relationship to cortisol. Kallikrein was inversely related to aldosterone. Excretion of inactive kallikrein followed closely the changes of active kallikrein. During cortisol excess, as in our patient, the mineralocorticoid activity of cortisol will exceed that of aldosterone. This suggests that the alterations in kallikrein, aldosterone and PGE2 during cortisol excess in the present study were due to the mineralocorticoid potency of the steroid.
Hans-Udo Schweikert, Horst Lorenz Fehm, Rudolf Fahlbusch, Rainer Martin, Rainer Kolloch, Miyoko Higuchi and Friedrich Krück
Abstract. A 55 year old woman with an unusual form of Cushing's disease was studied. During several periods (periods lasting up to 84 days) evidence of cortisol hypersecretion with cycles occurring every 6 days was found. Suppression of plasma cortisol through orally administered dexamethasone (up to 32 mg per day) could not be achieved either during periods of cyclic cortisol hypersecretion or during apparent remission with normal cortisol secretion. Marked suppression of plasma ACTH was measured in response to an iv infusion of 50 mg cortisol over a period of 55 min whereas a similar test with 2 mg dexamethasone (iv bolus) did not suppress ACTH secretion. Transsphenoidal exploration of the sella revealed a tumour surrounding the anterior pituitary. Examination of the pituitary showed a few tiny tumour structures embedded in normal tissue which could not be removed, when the tumour was resected selectively under preservation of normal appearing tissue. Post-operatively, clinical and chemical remission (normal response to 1 mg dexamethasone) was observed for about 4 months. Thereafter, cortisol hypersecretion occurred again necessitating bilateral adrenalectomy.
Our results are compatible with the assumption that normal hypothalamic-pituitary-adrenal suppressibility with cortisol, but not with dexamethasone, was caused by the loss of feedback receptors for dexamethasone in the presence of cortisol receptors in the cells which secrete ACTH or CRF.
The combination of cyclic hypercortisolism with dexamethasone non-suppressible Cushing's syndrome has not been reported before and thus represents a new variant of Cushing's syndrome.
Annegret Quade, Michael Rahn, Hans-Udo Schweikert, Frank Bidlingmaier and Dietrich Klingmüller
Urinary GH excretion reflects average plasma levels. Using a highly sensitive sandwich enzyme immunoassay we determined GH concentrations in the 24 h accumulated urine samples of 54 healthy persons (aged 1.5–90 years), 8 acromegalic patients, 4 acromegalic patients after enucleation of a GH-producing adenoma, 8 patients with partial hypopituitarism and in first morning urine and 12 h accumulated daytime urine of 4 healthy children and 3 children with growth failure. GH secretion is age-dependent, with high rates between ages 1 and 20 (ages 0–20 years: 10.4 ng/g creatinine±6.3 vs age > 20–75 years: 3.1 ng/g creatinine±1.6). An age-dependent increase in urinary GH is found in the pubertal age group (10 ng/24 h±6.8 vs prepubertal group: 4.6 ng/24 h±2.95). GH excretion of patients with acromegaly differs significantly from healthy subjects (72 ng/24 h±49 vs 3.9 ng/24 h±2.3). After a successful operation, acromegalic patients do not differ from the collective norm. Six of 8 patients with partial hypopituitarism show lower GH concentrations in urine than healthy subjects (1.2 ng/l±0.2 vs 2.6 ng/l±1.2), but daily GH output does not differ, since significantly more urine is then excreted. At night, healthy children secrete significantly more GH than during the day (night: 0.16 ng·kg−1·(12 h)−1±0.02 vs day: 0.07 ng·kg−1·(12 h)−1±0.03), while output is the same for GH-deficient children. Both groups have similar GH daytime output, but GH-deficient children have significantly less nocturnal output. In conclusion, measuring urinary GH excretion seems to be a suitable means of diagnosing GH hypo- and hypersecretion.