Metabolism of androstenedione in skin and serum levels of gonadotrophins and androgens in prepubertal boys with hypospadias

Prolactin secretion in the empty sella syndrome, in prolactinomas and in acromegaly

Prolactin (PRL) secretion was studied in 47 patients with empty sella syndrome. Hyperprolactinemia (39-123 micrograms/l) was found in six of them. Intermittent increases in PRL were noted in another seven patients. In most subjects with empty sella syndrome and hyperprolactinemia, diurnal PRL variation was altered or impaired whereas the PRL response to TRH and L-dopa was normal. Low doses of bromocriptine (3.75-5 mg/day) normalized PRL. In patients with prolactinoma and acromegaly who had prolactin levels of 30-165 micrograms/l the diurnal PRL variation and PRL response to TRH were impaired. Patients with prolactinoma failed to suppress PRL during L-dopa test. The dose of bromocriptine required to normalize PRL ranged between 7.5 and 15 mg/day. It is concluded that in subjects with sellar changes and intrasellar cisternal herniation ("empty sella"), and with moderate increases in PRL, the responses to TRH and L-dopa and to bromocriptine may help to differentiate between the empty sella syndrome and a coexisting pituitary tumour.

Dysregulation of the Hypothalamic-Pituitary-Gonadal Axis with Menopause and Andropause Promotes Neurodegenerative Senescence

Senescence is characterized neurologically by a decline in cognitive function, which we propose is the result of degenerative processes initiated by the dysregulation of the hypothalamic-pituitary-gonadal (HPG) axis with menopause and andropause. Compelling epidemiologic evidence to support this assertion includes the increased prevalence of Alzheimer disease (AD) in women, the correlation of serum HPG hormones with disease and the decreased incidence, and delay in the onset of AD following hormone replacement therapy. Dysregulation of the axis at this time leads to alterations in the concentrations of all serum HPG hormones (decreased neuronal sex steroid signaling, but increased neuronal gonadotropin releasing hormone, luteinizing hormone, and activin signaling). Hormones of the HPG axis, receptors for which are present in the adult brain, are important regulators of cell proliferation and differentiation during growth and development. Based on this, we propose that dysregulated HPG hormone signaling with menopause/andropause leads to the abortive reentry of differentiated neurons into the cell cycle via a process we term "dyosis." Interestingly, the major biochemical and neuropathologic changes reported for the AD brain also are intimately associated with neuron division: altered AbetaPP metabolism, Abeta deposition, tau phosphorylation, mitochondrial alterations, chromosomal replication, synapse loss, and death of differentiated neurons. Recent evidence supports the premise that AD-related biochemical changes are likely the combined result of increased mitotic signaling by gonadotropins and GnRH, decreased differentiative and neuroprotective signaling via sex steroids, and increased differentiative signaling via activins. This results in a hormonal milieu that is permissive of cell cycle reentry but does not allow completion of metaphase. Partial resetting of the axis following administration of normal endogenous sex steroids delays the onset and decreases the incidence of AD. Ideally, supplementation with HPG hormones should mimic closely the serum concentrations of all HPG hormones in reproductive men and cycling women to prevent dyotic signaling and attempted neuron division.

Androgen receptor levels and 5 alpha-reductase activities in preputial skin and chordee tissue of boys with isolated hypospadias

The cause of hypospadias in the majority of patients is unknown. We examined the hypothesis that hypospadias might be explained by androgen receptor abnormalities in the atretic spongiosal tissue commonly known as chordee. We studied 10 patients with relatively severe hypospadias but with a predominantly male phenotype and no readily ascertained explanation for the defect, including no evidence of an abnormality in testosterone biosynthesis. Eight subjects had midshaft hypospadias and 2 had a penoscrotal meatus. All 10 patients had severe chordee. Serum concentrations of testosterone, and luteinizing and follicle-stimulating hormones were measured before human chorionic gonadotropin stimulation and a serum testosterone level was determined 24 hours after the last dose of a 5-day human chorionic gonadotropin stimulation (3,000 units per M.2 per day). Androgen receptor content and binding affinity were assayed in fibroblasts cultured from preputial skin and chordee tissue of patients and foreskin from normal male neonates. With the endogenous ligand dihydrotestosterone the mean number (maximum binding capacity) of androgen receptors was 1,013 fmol. per mg. deoxyribonucleic acid in preputial skin and 833 fmol. per mg. deoxyribonucleic acid in chordee tissue of patients, and 627 fmol. per mg. deoxyribonucleic acid in the foreskin of controls. With the nonmetabolizable, synthetic androgen methyltrienolone (R1881) the mean maximum binding capacity was 1,004, 722 and 758 fmol. per mg. deoxyribonucleic acid, respectively. Dihydrotestosterone receptor affinity (dissociation constant) was similar in preputial skin (0.20 nM.) and chordee tissue (0.21 nM.) from patients, and foreskin (0.29 nM.) from controls. Androgen receptor binding affinity of R1881 also was similar (0.30, 0.24 and 0.21 nM., respectively). Furthermore, the 5 alpha-reductase activity of preputial skin and chordee tissue of patients with hypospadias was similar to that of foreskin from normal neonates. In conclusion, isolated hypospadias in these subjects was not associated with androgen insensitivity of the spongiosal tissues on the basis of either decreased androgen receptor binding affinity, receptor number or conversion of testosterone to dihydrotestosterone.

Gonadotropin and testosterone response in prepubertal boys with hypospadias

Serum levels of luteinizing hormone and follicle-stimulating hormone before and after luteinizing hormone-releasing hormone stimulation, and levels of testosterone before and after 3 days of treatment with human chorionic gonadotropin were determined by radioimmunoassay in 98 boys with hypospadias (2 to 8 years old). The doses of luteinizing hormone-releasing hormone and human chorionic gonadotropin were calculated for body surface. The basal and peak levels of serum luteinizing hormone, follicle-stimulating hormone and testosterone in patients with hypospadias were compared with 9 endocrinologically normal boys of the same age without hypospadias. Luteinizing hormone response to luteinizing hormone-releasing hormone stimulation was significantly impaired in boys with hypospadias and also simple hypospadias (no associated anomaly). Basal levels of luteinizing hormone in boys with simple hypospadias and levels of follicle-stimulating hormone in patients with hypospadias were significantly low. The maximum testosterone response to human chorionic gonadotropin stimulation was significantly decreased in boys with severe hypospadias in direct proportion to the degree of hypospadias.

A rapid, sensitive assay for analyzing defects in metabolism of steroids in normal and diseased human tissues

In this report, we describe a simple, rapid biopsy-steroid metabolism assay that is applicable to any steroid tissue system. It consists of mincing the sample, tissue culture incubation, extraction of the steroids and their metabolites from the tissue, and fractionation of the metabolites by high-pressure liquid chromatography (HPLC). Radioimmunoassay is used to verify the elution patterns of certain steroids. Studies of the metabolism of [3H]progesterone in the avian oviduct showed the generation of metabolites that eluted from the HPLC system in a pattern similar to androgens, estrogens, and glucocorticoids. Studies of the metabolism of [3H]testosterone in the human foreskin showed the production of metabolites that eluted from the HPLC system similar to 5 alpha-dihydrotestosterone and 5 alpha-androstane-3,17-dione (androstanedione) from the parent [3H]testosterone. In the production of the metabolite that eluted as androstanedione in samples of foreskin from normal subjects, a significant (P less than 0.001) correlation was found with the age of the donor. Preliminary studies of patients with hypospadias showed a significant (P less than 0.005) decrease in the production of "androstanedione" compared with that in normal subjects. Because of the wide range in rates of metabolism of testosterone in the patients with hypospadias, the effect of age does not seem to be the sole determinant of a low rate of metabolism in these patients. Some samples of hypospadias foreskin had a decreased rate of production of a metabolite that eluted as dihydrotestosterone in comparison with normal foreskin, even when the age of the donor was considered. The assay described herein should be applicable to any surgical biopsy specimen and to all steroids.(ABSTRACT TRUNCATED AT 250 WORDS)

Fibroblast androgen receptors in patients with genitourinary anomalies

The etiology of certain disorders of sexual differentiation is unclear. The authors have examined the hypothesis that hypospadias and other disorders compatible with a defect in androgen action, such as cryptorchidism, micropenis, chordee/penile torsion, and ectopic testis, might be explained by androgen receptor abnormalities. Therefore, 25 subjects were studied who were selected only because they had one of these developmental defects, together with a predominantly male phenotype, and no readily ascertainable explanation for the defect. Four of these subjects had mixed gonadal dysgenesis with multiple genito-urinary anomalies. They were included for comparative purposes, since there is no evidence for androgen resistance in this disorder. Patients with testicular regression syndrome (gross testosterone deficiency), impaired testosterone biosynthesis (relative testosterone deficiency), 5 alpha-reductase deficiency (altered T/DHT ratio), and a family history or endocrine profile suggestive of androgen resistance, were all excluded from evaluation. Androgen receptor content (R0) and binding affinity (Kd) were measured in 26 genital or pubic skin fibroblast strains cultured from 25 affected patients using a dispersed, whole cell assay at 22 C. There was no difference in the mean androgen receptor content (approximately 10,000 sites/cell) or binding affinity (approximately 1 nM) between the patients' fibroblasts and those from 26 fibroblast strains established from 26 normal males. Moreover, there were no differences in the nuclear uptake of [3H]dihydro-testosterone into dispersed, intact fibroblasts incubated at 37 C when 11 patient and seven normal male fibroblast strains were compared.(ABSTRACT TRUNCATED AT 250 WORDS)

Social and sexual adjustment of men operated for hypospadias during childhood: a controlled study

In a controlled study 34 men operated on for hypospadias in childhood and 36 control subjects were interviewed concerning their sexual and social adjustment, which at the time of the interviews was shown to be virtually similar in the 2 groups. Most of the hypospadiacs had stable sexual relationships but they had been sexually less active than the controls. The sexual debut of the hypospadiacs was retarded although the age at first ejaculation was the same as for the controls. The hypospadiacs had less qualified professions compared to the controls. The results indicate the possibility of operated hypospadiacs being psychologically different from other men. Fertility seems to be equal in the 2 groups and even patients with severe forms of hypospadias reported fertility. The issue of optimal ambition in surgical repair is discussed in view of the fact that even patients with a less than perfect technical result are able to live a satisfactory sexual life.

A simplified radioimmunoassay for melatonin and its application to biological fluids. Preliminary observations on the half-life of plasma melatonin in man

A simplified and rapid radioimmunoassay (RIA) for melatonin is presented. Melatonin is extracted from seru, plasma or urine and RIA is performed by using [3H]melatonin as the tracer. The standard curve covers the range 0.2--4.3 nmol/l. By increasing the sample volume the range can be extended to 0.06 nmol/l. The intra-assay variability is 7% (relative standard deviation = rsd) and the inter-assay variability is 10% (rsd). The recovery of melatonin added to calf serum is 96%. The long term variability of the assay (43 assays on aliquots of one serum sample during 6 months) is 13.5% (rsd). The serum levels in man after one oral dose of 430 mumol melatonin have been measured. The peak value, 620 nmol/l, was noted after 0.5 h and the melatonin concentration was still above the normal range at 24 h (2.1 nmol/l).