estradiol

luteinizing hormone (LH)

Justification not yet generated — showing supporting facts

• Medical professionals typically conduct symptom assessments and order blood tests, including total testosterone, bioavailable or free testosterone, SHBG, LH, FSH, estradiol, cortisol rhythms, thyroid markers, and basic metabolic panels, to diagnose male hormonal issues.
• To produce the critical concentration of estradiol required to initiate positive feedback for the luteinizing hormone (LH) surge, the dominant follicle is almost always greater than 15mm in diameter as measured by ultrasound.
• The luteinizing hormone (LH) surge is initiated by a dramatic rise in estradiol produced by the preovulatory follicle.
• The secretion of progesterone and estradiol during the luteal phase is episodic and correlates closely with pulses of Luteinizing hormone (LH) secretion.
• The pre-ovulatory fall in estradiol may be caused by luteinizing hormone (LH) downregulation of its own receptor or by direct inhibition of estradiol synthesis by progesterone.
• For the positive feedback effect of Luteinizing hormone (LH) release to occur, estradiol levels must be greater than 200 pg/mL for approximately 50 hours.
• Estradiol levels fall dramatically immediately prior to the luteinizing hormone (LH) peak.
• The menstrual cycle is regulated by the hormones GnRH, FSH, LH, estradiol, and progesterone.
• The secretion of progesterone and estradiol during the luteal phase is episodic and correlates closely with pulses of LH secretion.
• In the presence of estradiol, follicle-stimulating hormone (FSH) stimulates the formation of luteinizing hormone (LH) receptors on granulosa cells, allowing for the secretion of small quantities of progesterone and 17-hydroxyprogesterone (17-OHP), which may exert a positive feedback on the estrogen-primed pituitary to augment LH release.
• For the positive feedback effect of Luteinizing hormone (LH) release to occur, estradiol levels must exceed 200 pg/mL for approximately 50 hours.
• The two-cell, two-gonadotropin hypothesis of regulation of estrogen synthesis in the human ovary states that LH stimulates theca cells to produce androstenedione, which is then transported to granulosa cells where it is aromatized to estrone and converted to estradiol by 17-β-hydroxysteroid dehydrogenase type I.
• Luteinizing hormone (LH) and follicle-stimulating hormone (FSH) promote ovulation and stimulate the ovaries to secrete the sex hormones estradiol (an estrogen) and progesterone.
• Sherman B.M., West J.H., and Korenman S.G. published a 1976 study in the Journal of Clinical Endocrinology and Metabolism analyzing LH, FSH, estradiol, and progesterone concentrations during the menstrual cycles of older women.
• Estradiol levels fall dramatically immediately prior to the luteinizing hormone (LH) peak, potentially due to LH downregulation of its own receptor or direct inhibition of estradiol synthesis by progesterone.

progesterone

Progesterone and estradiol are both primary sex hormones that regulate the menstrual cycle [1] and are secreted by the ovaries under the influence of LH and FSH [2]. Their levels are closely linked throughout the luteal phase {fact:2, fact:10, fact:13}, with progesterone acting to modulate the biologic activity of estradiol on the endometrium [3] and potentially inhibiting its synthesis {fact:5, fact:8}. — 15 supporting facts

estrogen

Estradiol is a specific hormone classified as a member of the estrogen group, as explicitly stated in [1] and [2]. Furthermore, the dominant follicle secretes estrogen primarily in the form of estradiol [3], and both substances share physiological roles in inhibiting GnRH secretion [4] and influencing bone and vascular health [5]. — 8 supporting facts

menstrual cycle

Estradiol is a primary hormone that regulates the menstrual cycle [1], [2], specifically driving the maturation of the egg and uterine lining [3]. Furthermore, fluctuations in estradiol levels are intrinsically linked to the phases of the menstrual cycle [4], [5] and the eventual cessation of the cycle during menopause [6]. — 7 supporting facts

ovulation

The relationship between ovulation and estradiol is established by the fact that a rise in estradiol triggers the LH surge that leads to ovulation [1], [2], and that ovulation subsequently stimulates the ovaries to secrete estradiol [3]. Additionally, peak serum levels of estradiol are observed in the days following ovulation [4], [5], [6]. — 6 supporting facts

luteal phase

The luteal phase is characterized by the episodic secretion of estradiol [1], which exhibits a secondary rise during the mid-luteal phase [2] and is subject to regulation by progesterone [3] and FSH [4]. — 6 supporting facts

testosterone

Testosterone is directly converted to estradiol in the periphery via the enzyme aromatase [1][2], and they are linked in Klinefelter syndrome by a high estradiol:testosterone ratio [3]. Both hormones inhibit GnRH secretion [4], and shared precursors like DHEA and androstenedione can be converted to either [5]. — 5 supporting facts

follicular phase

The follicular phase is characterized by specific fluctuations in estradiol production and serum levels, as evidenced by the daily production rates [1] and the parallel rise of estradiol with follicle growth [2]. Furthermore, rising estradiol levels during the late follicular phase are responsible for physiological changes in cervical mucus [3] and vaginal epithelial cells [4]. — 4 supporting facts