Leap of Faith: Does Serum Luteinizing Hormone Always Accurately Reflect Central Reproductive Neuroendocrine Activity?
The function of the central aspects of the hypothalamic-pituitary-gonadal axis has been assessed in a number of ways including direct measurements of the hypothalamic output and indirect measures using gonadotropin release from the pituitary as a bioassay for reproductive neuroendocrine activity. Here, methods for monitoring these various parameters are briefly reviewed and then examples presented of both concordance and discrepancy between central and peripheral measurements, with a focus on situations in which elevated gonadotropin-releasing hormone neurosecretion is not reflected accurately by pituitary luteinizing hormone release. Implications for the interpretation of gonadotropin data are discussed.
Department of Molecular and Integrative Physiology, Internal Medicine, and Obstetrics and Gynecology, University of Michigan, Ann Arbor, Mich., USA.
Suzanne M
SM
Moenter