Gonadorelin Archives - Revista Brasileira de Ginecologia e Obstetrícia
Summary
Revista Brasileira de Ginecologia e Obstetrícia. 2007;29(1):48-55
DOI 10.1590/S0100-72032007000100008
Changes in the levels of gonadotropins throughout the reproductive life depend on a fine tuned functional development of neural pathways and GnRH-neurones, pituitary gonadotrophs and granulosa-theca cells of the follicular wall. Both, LH and FSH levels change according to the day-time, menstrual cycle phase, and gynecological age. Initiating the puberty, changes in LH pulses are remarkable, showing higher frequency and amplitude at night. Later in puberty, the pulses of LH are also maintained during the day, remaining its levels with very little variation within the 24 hours period. During the menstrual cycle, the FSH levels increase at the end of the luteal phase, decrease during the medium and late follicular phase, increase rapidly in the ovulatory phase and remain at low basal levels until the late luteal phase. The levels of LH remain unaltered during the whole follicular phase, increase in the ovulatory surge, and decrease to the basal levels in the luteal phase. At the forth decade of life, the GnRH secretion changes, with hypothalamic loss of sensitivy to the estradiol positive feedback and decrease in frequency and prolongation of the GnRH pulses. The pituitary response is atenuated due to decrease in the density of GnRH receptors on gonadotroph cells, loss of gonadotroph sensitivity, secretion of more basic FSH and LH molecules, decrease in frequency and increase in amplitude of LH and FSH pulses. These modifications result in monotropic increase of the FSH secretion. Current studies show that the selective increase in the FSH levels in the early follicular phase is gradual, beginning as early as the third decade of life. These alterations in FSH are associated with an accelerated follicular depletion in women after 37-38 years old. On the other side, the LH levels remain almost constant up to the end of reproductive life. The different levels of FSH and LH seen throughout the reproductive years may be due to yet unknown regulatory mechanisms in the hypothalamic-pituitary-ovarian axis.
Summary
Revista Brasileira de Ginecologia e Obstetrícia. 2007;29(1):48-55
DOI 10.1590/S0100-72032007000100008
Changes in the levels of gonadotropins throughout the reproductive life depend on a fine tuned functional development of neural pathways and GnRH-neurones, pituitary gonadotrophs and granulosa-theca cells of the follicular wall. Both, LH and FSH levels change according to the day-time, menstrual cycle phase, and gynecological age. Initiating the puberty, changes in LH pulses are remarkable, showing higher frequency and amplitude at night. Later in puberty, the pulses of LH are also maintained during the day, remaining its levels with very little variation within the 24 hours period. During the menstrual cycle, the FSH levels increase at the end of the luteal phase, decrease during the medium and late follicular phase, increase rapidly in the ovulatory phase and remain at low basal levels until the late luteal phase. The levels of LH remain unaltered during the whole follicular phase, increase in the ovulatory surge, and decrease to the basal levels in the luteal phase. At the forth decade of life, the GnRH secretion changes, with hypothalamic loss of sensitivy to the estradiol positive feedback and decrease in frequency and prolongation of the GnRH pulses. The pituitary response is atenuated due to decrease in the density of GnRH receptors on gonadotroph cells, loss of gonadotroph sensitivity, secretion of more basic FSH and LH molecules, decrease in frequency and increase in amplitude of LH and FSH pulses. These modifications result in monotropic increase of the FSH secretion. Current studies show that the selective increase in the FSH levels in the early follicular phase is gradual, beginning as early as the third decade of life. These alterations in FSH are associated with an accelerated follicular depletion in women after 37-38 years old. On the other side, the LH levels remain almost constant up to the end of reproductive life. The different levels of FSH and LH seen throughout the reproductive years may be due to yet unknown regulatory mechanisms in the hypothalamic-pituitary-ovarian axis.
Summary
Revista Brasileira de Ginecologia e Obstetrícia. 2006;28(7):410-415
DOI 10.1590/S0100-72032006000700006
PURPOSE: to verify, through pelvic ultrasound, the existence of changes in the internal genitalia of girls with central precocious puberty, submitted to treatment with gonadotrophin-releasing hormone (GnRH) analogs. METHODS: pelvic ultrasound was performed in 18 girls with idiopathic central precocious puberty, before and after three months of onset of the treatment with GnRH analogs, to investigate the impact of the therapy on the internal genitalia. Ovarian and uterine volumes, uterine longitudinal length, relation between the longitudinal diameter of the uterine corpus and the uterine cervix, the relation between the anterior-posterior diameter of the uterine corpus and the uterine cervix, and endometrial echogenicity were evaluated. Statistical analysis was performed through Shapiro-Willkis's test, to assess data normality. When normality was present, Student's test t was applied. For data without normality, a non-parametric test (the signal test) was used. RESULTS: after therapy, statistically significant decline of the mean uterine volume (from 5.4 cm³ to 3.0 cm³, p<0.001), of the mean ovarian volume (from 2.2 cm³ to 1.1 cm³, p= 0.004), of the mean uterine longitudinal length (from 4.2cm to 3.4 cm, p=0.001), and of the mean endometrial echogenicity (from 1.8 mm to 0.6 mm, p=0.018) occurred. CONCLUSION: In girls with idiopathic central precocious puberty, pelvic ultrasound is a valid method to assess the efficacy of treatment with GnRH analogs. The main parameters of the therapeutic response were the decrease of uterine and ovarian volume, of uterine longitudinal length, and atrophy or absence of endometrial echogenicity.
Summary
Revista Brasileira de Ginecologia e Obstetrícia. 2006;28(7):410-415
DOI 10.1590/S0100-72032006000700006
PURPOSE: to verify, through pelvic ultrasound, the existence of changes in the internal genitalia of girls with central precocious puberty, submitted to treatment with gonadotrophin-releasing hormone (GnRH) analogs. METHODS: pelvic ultrasound was performed in 18 girls with idiopathic central precocious puberty, before and after three months of onset of the treatment with GnRH analogs, to investigate the impact of the therapy on the internal genitalia. Ovarian and uterine volumes, uterine longitudinal length, relation between the longitudinal diameter of the uterine corpus and the uterine cervix, the relation between the anterior-posterior diameter of the uterine corpus and the uterine cervix, and endometrial echogenicity were evaluated. Statistical analysis was performed through Shapiro-Willkis's test, to assess data normality. When normality was present, Student's test t was applied. For data without normality, a non-parametric test (the signal test) was used. RESULTS: after therapy, statistically significant decline of the mean uterine volume (from 5.4 cm³ to 3.0 cm³, p<0.001), of the mean ovarian volume (from 2.2 cm³ to 1.1 cm³, p= 0.004), of the mean uterine longitudinal length (from 4.2cm to 3.4 cm, p=0.001), and of the mean endometrial echogenicity (from 1.8 mm to 0.6 mm, p=0.018) occurred. CONCLUSION: In girls with idiopathic central precocious puberty, pelvic ultrasound is a valid method to assess the efficacy of treatment with GnRH analogs. The main parameters of the therapeutic response were the decrease of uterine and ovarian volume, of uterine longitudinal length, and atrophy or absence of endometrial echogenicity.