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Aging in humans is accompanied by a progressive decline in the secretion of the adrenal androgens dehydroepiandrosterone (DHEA) and DHEA sulfate (DS), paralleling that of the GH-insulin-like growth factor-I (GH-IGF-I) axis. Although the functional relationship of the decline of the GH-IGF-I system and catabolism is recognized, the biological role of DHEA in(More)
The physiological role of intraovarian activin (beta/beta) and inhibin (alpha/beta) dimers in humans in unclear. The identification of follistatin as a beta-subunit-specific high affinity binding protein has added complexities for the interpretation of in vitro studies concerning the functionalities of these ovarian peptides. We, therefore, have attempted(More)
1Division of Reproductive Medicine, Department of Obstetrics and Gynecology, Erasmus University Medical Center Rotterdam, Rotterdam, The Netherlands, 2Department of Reproductive Medicine, Dutch speaking Free University Brussels, Brussels, Belgium, 3Department of Reproductive Medicine, Division of Reproductive Endocrinology, University of California, San(More)
OBJECTIVE The biological role of the adrenal sex steroid precursors--DHEA and DHEA sulphate (DS) and their decline with ageing remains undefined. We observed previously that administration of a 50 daily dose of DHEA for 3 months to age-advanced men and women resulted in an elevation (10%) of serum levels of insulin-like growth factor-I (IGF-I) accompanied(More)
The dynamics of ovarian and pituitary hormone changes during the midcycle period were evaluated. Changes in hormone levels were determined at 2-h intervals for 5 consecutive days during the periovulatory phase of the cycle in five women. During the 50 h preceding the onset of the surge, the rates of increments for estradiol (E2), progesterone (P4), and LH(More)
The development of functional hypothalamic amenorrhea (FHA) in weight-stable, nonathletic women has long been thought to be psychogenic in origin. This study was designed to gain insight into the possibility that nutritional deficits and compensatory endocrine-metabolic adaptations contribute to the development and maintenance of FHA of the psychogenic(More)
Growing evidence suggests that menstrual disturbances in female athletes are related to the metabolic cost of high levels of energy expenditure without compensatory increases in dietary intake. However, the linkage(s) between nutritional deficits and reproductive impairments as a result of slowing of LH pulsatility has not been defined. This study was(More)
It has been postulated that dehydroepiandrosterone (DHEA) and its sulfate ester, dehydroepiandrosterone sulfate (DHEAS), the major secretory products of the human adrenal gland, may be discriminators of life expectancy and aging. We examined the relation of base-line circulating DHEAS levels to subsequent 12-year mortality from any cause, from(More)
The brain is a steroidogenic organ that expresses steroidogenic enzymes and produces neurosteroids. Although considerable information is now available regarding the steroidogenic capacity of the brain, little is known regarding the steroidogenic pathway and relative contributions of astrocytes, oligodendrocytes, and neurons to neurosteroidogenesis. In the(More)