Hypogonadism — Investigating the Regulation of Reproductive Hormones in Adult Men
Citation(s)
Bagatell CJ, Dahl KD, Bremner WJ The direct pituitary effect of testosterone to inhibit gonadotropin secretion in men is partially mediated by aromatization to estradiol. J Androl. 1994 Jan-Feb;15(1):15-21.
Culler MD, Negro-Vilar A Passive immunoneutralization of endogenous inhibin: sex-related differences in the role of inhibin during development. Mol Cell Endocrinol. 1988 Aug;58(2-3):263-73.
Finkelstein JS, O'Dea LS, Whitcomb RW, Crowley WF Jr Sex steroid control of gonadotropin secretion in the human male. II. Effects of estradiol administration in normal and gonadotropin-releasing hormone-deficient men. J Clin Endocrinol Metab. 1991 Sep;73(3):621-8.
Hayes FJ, Hall JE, Boepple PA, Crowley WF Jr Clinical review 96: Differential control of gonadotropin secretion in the human: endocrine role of inhibin. J Clin Endocrinol Metab. 1998 Jun;83(6):1835-41. Review.
Santen RJ Is aromatization of testosterone to estradiol required for inhibition of luteinizing hormone secretion in men? J Clin Invest. 1975 Dec;56(6):1555-63.
Sonino N The use of ketoconazole as an inhibitor of steroid production. N Engl J Med. 1987 Sep 24;317(13):812-8. Review.
Van Tyle JH Ketoconazole. Mechanism of action, spectrum of activity, pharmacokinetics, drug interactions, adverse reactions and therapeutic use. Pharmacotherapy. 1984 Nov-Dec;4(6):343-73. Review.
Veldhuis JD, Johnson ML Cluster analysis: a simple, versatile, and robust algorithm for endocrine pulse detection. Am J Physiol. 1986 Apr;250(4 Pt 1):E486-93.
Winters SJ, Janick JJ, Loriaux DL, Sherins RJ Studies on the role of sex steroids in the feedback control of gonadotropin concentrations in men. II. Use of the estrogen antagonist, clomiphene citrate. J Clin Endocrinol Metab. 1979 Feb;48(2):222-7.
Ying SY Inhibins, activins, and follistatins: gonadal proteins modulating the secretion of follicle-stimulating hormone. Endocr Rev. 1988 May;9(2):267-93. Review.
Feedback Control of FSH Secretion in the Human Male
Interventional studies are often prospective and are specifically tailored to evaluate direct impacts of treatment or preventive measures on disease.
Observational studies are often retrospective and are used to assess potential causation in exposure-outcome relationships and therefore influence preventive methods.
Expanded access is a means by which manufacturers make investigational new drugs available, under certain circumstances, to treat a patient(s) with a serious disease or condition who cannot participate in a controlled clinical trial.
Clinical trials are conducted in a series of steps, called phases - each phase is designed to answer a separate research question.
Phase 1: Researchers test a new drug or treatment in a small group of people for the first time to evaluate its safety, determine a safe dosage range, and identify side effects.
Phase 2: The drug or treatment is given to a larger group of people to see if it is effective and to further evaluate its safety.
Phase 3: The drug or treatment is given to large groups of people to confirm its effectiveness, monitor side effects, compare it to commonly used treatments, and collect information that will allow the drug or treatment to be used safely.
Phase 4: Studies are done after the drug or treatment has been marketed to gather information on the drug's effect in various populations and any side effects associated with long-term use.