Follicle Stimulating Hormone (FSH) Glycosylation in Women: Effect of Estradiol
Brief description: This clinical trial is an investigational research study to determine the ratio of glycosylated FSH21/FSH24 in premenopausal women and postmenopausal women as well as determining if estradiol can increase this ratio in postmenopausal women.
Detailed description: Follicle Stimulating Hormone (FSH), is secreted by the pituitary gland at the base of the brain, and is the primary stimulus for growth of the ovarian follicle that contains the egg. Glycosylation, or adding glucose, to FSH is critical for its bioactivity on stimulating the ovarian follicle. The FSH with less glycosylation (FSH21) has a higher affinity for the FSH receptor and activates more pathways than does fully-glycosylated FSH (FSH24). Previous studies showed pituitaries from young women contain a high ratio of FSH21/FSH24 while pituitaries from older and postmenopausal women have a lower ratio of FSH21/FSH24. The investigators hypothesize that the higher FSH21/FSH24 ratio found in young women is responsible for normal follicle growth. This study is intended to provide the first determination of systemic changes in the ratio of FSH21/FSH24 and determine if estradiol increases the FSH21/FSH24 ratio in the first morning urine of women. To take part in this study, the participant must be willing to collect the first morning urine on particular mornings of the menstrual cycle and be available for blood draws on those mornings. Additionally for postmenopausal participants, the participant must be willing to use topical estrogen, EstroGel©, for 14 days and be willing to collect the first morning urine on particular mornings and again be available for blood draws on those mornings. For the postmenopausal participants with an intact uterus, the participants must be willing to take an oral progestin, micronized progesterone, for 12 days following the completion of the study.
Detailed description: Follicle Stimulating Hormone (FSH), is secreted by the pituitary gland at the base of the brain, and is the primary stimulus for growth of the ovarian follicle that contains the egg. Glycosylation, or adding glucose, to FSH is critical for its bioactivity on stimulating the ovarian follicle. The FSH with less glycosylation (FSH21) has a higher affinity for the FSH receptor and activates more pathways than does fully-glycosylated FSH (FSH24). Previous studies showed pituitaries from young women contain a high ratio of FSH21/FSH24 while pituitaries from older and postmenopausal women have a lower ratio of FSH21/FSH24. The investigators hypothesize that the higher FSH21/FSH24 ratio found in young women is responsible for normal follicle growth. This study is intended to provide the first determination of systemic changes in the ratio of FSH21/FSH24 and determine if estradiol increases the FSH21/FSH24 ratio in the first morning urine of women. To take part in this study, the participant must be willing to collect the first morning urine on particular mornings of the menstrual cycle and be available for blood draws on those mornings. Additionally for postmenopausal participants, the participant must be willing to use topical estrogen, EstroGel©, for 14 days and be willing to collect the first morning urine on particular mornings and again be available for blood draws on those mornings. For the postmenopausal participants with an intact uterus, the participants must be willing to take an oral progestin, micronized progesterone, for 12 days following the completion of the study.