Peter J Illingworth

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This report describes the development of a specific and sensitive assay for inhibin B and its application to the measurement of inhibin B concentrations in plasma during the human menstrual cycle. A monoclonal antibody raised against a synthetic peptide from the betaB-subunit was combined with an antibody to an inhibin alpha-subunit sequence in a double(More)
We used a recently developed ELISA format to test the hypothesis that inhibin B is the physiologically active form of inhibin in men. We measured and compared inhibin A, inhibin B, and pro-alpha-C-related immunoreactive peptides (pro-alpha-C-RI) in normal men before and after perturbations of their gonadotropin levels and baseline values in normal men and(More)
UNLABELLED This study sought to compare circulating and follicular fluid (FF) concentrations of dimeric inhibin A and B utilizing specific two-site ELISAs for these hormones in normal older and younger ovulatory women. METHODS. Normally ovulating women age 40-45 (n = 10) and 20-25 (n = 13) were studied throughout the follicular phase with daily blood(More)
Inhibin is a glycoprotein hormone that is defined on the basis of inhibition of pituitary FSH production, However, previous data have not shown any correlation between RIA measurements of inhibin and FSH in men. New enzyme-linked immunosorbent assays, specific for inhibin A, inhibin B, and inhibin pro-alphaC-related immunoreactivity, were applied to the(More)
OBJECTIVE We have developed and validated a two-site immunoassay for the measurement of dimeric inhibin in plasma and subsequently measured dimeric inhibin levels in plasma through the normal female menstrual cycle. DESIGN Recombinant inhibin added to plasma samples was quantitatively recovered in both follicular and luteal phase, and serial dilutions of(More)
Luteal progesterone production is dependent on luteinizing hormone (LH) from the pituitary gland. Despite continuing LH secretion, the human corpus luteum undergoes functional luteolysis unless it is 'rescued' by human chorionic gonadotrophin (HCG), produced by the implanting blastocyst. As LH and HCG act through a common receptor, this study sought to(More)
Effects of inhibin (recombinant human inhibin-A) on ovarian androgen synthesis were tested in vitro using serum-free monolayer cultures of human thecal cells. Treatment for 4 days with inhibin alone at doses between 10 and 100 ng/ml caused modest (approximately 2-fold) increases in production of androgen (androstenedione and dehydroepiandrosterone): similar(More)
Luteolysis is associated with tissue remodeling probably involving the matrix metalloproteinases (MMPs) and their specific tissue inhibitors (TIMPs). This study investigated the expression and localization of the major MMPs and TIMPs in the human corpus luteum throughout the luteal phase and after luteal rescue with hCG. Corpora lutea (n = 9) were collected(More)
Precursor forms of the alpha-subunit of inhibin are abundant in human follicular fluid and possibly plasma, although their function is uncertain. We now describe the development of a new enzyme-linked immunosorbent assay to measure inhibin forms containing both the pro and alpha C regions of the alpha-subunit. The assay has a detection limit for purified(More)
The effect of activin-A on ovarian androgen synthesis was tested in vitro using serum-free monolayer cultures of human thecal cells. Maximal rates of androgen (androstenedione and dehydroepiandrosterone) production were induced by treating the cells for 4 days with LH (10 ng/mL) in the presence of insulin-like growth factor-I (greater than or equal to 30(More)