scholarly journals Chronic estrus disrupts uterine gland development and homeostasis

2018 ◽  
Author(s):  
C. Allison Stewart ◽  
M. David Stewart ◽  
Ying Wang ◽  
Rui Liang ◽  
Yu Liu ◽  
...  

AbstractFemale mice homozygous for an engineered Gnrhr E90K mutation have reduced gonadotropin-releasing hormone signaling, leading to infertility. Their ovaries have numerous antral follicles but no corpora lutea, indicating a block to ovulation. These mutants have high levels of circulating estradiol and low progesterone, indicating a state of persistent estrus. This mouse model provided a unique opportunity to examine the lack of cyclic levels of ovarian hormones on uterine gland biology. Although uterine gland development appeared similar to controls during prepubertal development, it was compromised during adolescence in the mutants. By 20 weeks of age, uterine gland development was comparable to controls, but pathologies, including squamous neoplasia, tubal neoplasia, and cribriform glandular structures, were observed. Induction of ovulations by periodic human chorionic gonadotropin treatment did not rescue post-pubertal uterine gland development. Interestingly, progesterone receptor knockout mice, which lack progesterone signaling, also have defects in post-pubertal uterine gland development. However, progesterone treatment did not rescue post-pubertal uterine gland development. These studies indicate that chronically elevated levels of estradiol with low progesterone and therefore an absence of cyclic ovarian hormone secretion disrupts post-pubertal uterine gland development and homeostasis.

2001 ◽  
Vol 13 (3) ◽  
pp. 133 ◽  
Author(s):  
P. M. Bartlewski ◽  
A. P. Beard ◽  
C. L. Chapman ◽  
M. L. Nelson ◽  
B. Palmer ◽  
...  

The relationships between the development of antral follicles (growing from 3 to ≥5 mm diameter), hormone secretion (luteinizing hormone (LH), follicle-stimlating hormone (FSH), oestradiol and progesterone), ovulation and the formation of luteal structures in response to gonadotrophin-releasing hormone (GnRH) were examined in 24 anoestrous Western White Face ewes (May–July). Ewes were monitored by transrectal ovarian ultrasonography for 34 days, commencing 15 days before the administration of GnRH. Following treatment with GnRH, 83% (20/24) of ewes ovulated. Twenty-five per cent of all ewes (6/24) subsequently had normal (full-life span) corpora lutea (CL), 37% (9/24) had inadequate CL, 17% (4/24) had both normal and inadequate CL, 17% (including three of four anovular ewes and one ewe with inadequate CL) formed luteinized follicles and only 4% (1/24) did not ovulate or produce any luteal structure. None of the variables of follicular growth (follicles reaching ≥5 mm diameter) differed between follicles that either ovulated or failed to ovulate and there was no evident correlation between the age or stage of development of ovulatory sized antral follicles and the type of luteal structure formed, except for luteinized unovulated follicles; these follicles all emerged within 3 days of GnRH injection. Mean serum concentrations of FSH and oestradiol before treatment did not differ (P> 0.05) between ewes with different ovarian responses, but peaks of fluctuations in serum concentrations of FSH in daily samples were higher in ewes that produced normal CL compared with ewes with inadequate CL. After GnRH treatment, oestradiol secretion was higher in ewes that formed luteinized unovulated follicles than in all ewes with inadequate CL (P> 0.05). The peak concentration of the GnRH-induced LH surge was higher and the interval from GnRH to peak LH discharge was shorter in ewes with inadequate CL compared with ewes that had normal CL after ovulation (P> 0.05). In conclusion, ovulatory sized antral follicles at a similar stage of their life span can give rise to either normal or inadequate CL and a proportion of these follicles do not ovulate in response to GnRH in seasonally anoestrous ewes. This suggests differences in ovarian follicular responsiveness to gonadotrophic stimuli. Both the amplitude of episodic elevations in daily serum FSH concentrations and the characteristics of the pre-ovulatory LH surge may be important for luteogenesis following ovulation.


Reproduction ◽  
2014 ◽  
Vol 147 (2) ◽  
pp. 189-197 ◽  
Author(s):  
Noriyuki Takahashi ◽  
Wataru Tarumi ◽  
Bunpei Ishizuka

Most of the previous studies on ovarian hyaluronan (HA) have focused on mature antral follicles or corpora lutea, but scarcely on small preantral follicles. Moreover, the origin of follicular HA is unknown. To clarify the localization of HA and its synthases in small growing follicles, involvement of HA in follicle growth, and gonadotropin regulation of HA synthase (Has) gene expression, in this study, perinatal, immature, and adult ovaries of Wistar-Imamichi rats were examined histologically and biochemically and byin vitrofollicle culture. HA was detected in the extracellular matrix of granulosa and theca cell layers of primary follicles and more advanced follicles. Ovarian HA accumulation ontogenetically started in the sex cords of perinatal rats, and its primary site shifted to the intrafollicular region of primary follicles within 5 days of birth. TheHas1–3mRNAs were expressed in the ovaries of perinatal, prepubertal, and adult rats, and the expression levels ofHas1andHas2genes were modulated during the estrous cycle in adult rats and following administration of exogenous gonadotropins in immature acyclic rats. TheHas1andHas2mRNAs were predominantly localized in the theca and granulosa cell layers of growing follicles respectively. Treatments with chemicals known to reduce ovarian HA synthesis induced follicular atresia. More directly, the addition ofStreptomyceshyaluronidase, which specifically degrades HA, induced the arrest of follicle growth in anin vitroculture system. These results indicate that gonadotropin-regulated HA synthesis is involved in normal follicle growth.


2020 ◽  
Vol 73 (5) ◽  
pp. 868-872
Author(s):  
Iryna M. Nikitina ◽  
Volodymyr I. Boiko ◽  
Svitlana A. Smiian ◽  
Tetiana V. Babar ◽  
Natalia V. Kalashnyk ◽  
...  

The aim: The aim of the study was to improve the results of treatment of patients with endometriosis by using a combination method of therapy. Materials and methods: For two years, 136 women of reproductive age who underwent laparoscopic surgeries for ovarian endometriosis were monitored: Group I (n = 24) did not receive any hormonal treatment in the perioperative period; Group II (n = 32) – received gonadotropin-releasing hormone agonists within 3 months after surgery; Group III (n = 80) prior to laparoscopic removal of the ovarian cyst used gonadotropin-releasing hormone agonists – Triptorelin 3.75 mg intramuscularly for 2 months, as well as three months after surgery. The control group consisted of 30 healthy women of reproductive age with regular menstrual periods. All patients underwent transvaginal ultrasound, counting the number of antral follicles before and after treatment. Serum hormone levels (FSH, prolactin, thyrotropic hormone, anti-Mullerian hormone, inhibin B) were determined by enzyme-linked immunosorbent assay on Cobas e-411 analyzer (Roche Diagnostics, Switzerland) on day 2-3 of the menstrual cycle and on day 2–3 of the first menstrual period after the end of treatment. Laparoscopic removal of the cyst was performed with exfoliation of the cyst, hemostasis on the wound surface of the bed of the cyst was performed with a bipolar electrocoagulator. Bipolar coagulation and resection of the ovarian tissue with no potential was used during surgical treatment of the ovaries, which made it possible to preserve the intact portion of the ovary as much as possible. Results: Analysis of ovarian reserve indices, namely number of antral foliculs, number of antral follicles, AMG, and inhibin B levels in all examined patients with ovarian endometriomas were significantly lower than those of the control group before the start of treatment: in the ovarian endometrial group group 1.26 times (p <0.01), inhibin B – 1.5 times (p <0.01), the number of antral follicles – 1.2 times (p <0.01), due to the development dystrophic changes of the follicular apparatus due to prolonged compression, hypoxia, fibrosis in the ovaries. Patients who planned pregnancy were advised to have an active sexual life before menstruation was restored. In 23 (46.9%) of 49 patients who had reproductive plans, pregnancy occurred without first menstruation after a course of gonadotropin-releasing hormone agonists, 12 (24.5%) women became pregnant during the first three menstrual cycles. Extracorporeal fertilization was recommended for women who did not have pregnancy within 6 months of surgery. For two years in women who did not plan pregnancy, recurrence of endometriosis was not observed. Conclusions: The combination of laparoscopic treatment with gonadotropin-releasing hormone agonists in patients with endometriosis with infertility allowed to restore reproductive function in 71.4% of women, which indicates the effectiveness of the treatment method used. In addition, it helps to achieve lasting remission and addresses the socio-social problems of women’s health and maternity.


2018 ◽  
Vol 50 (5S) ◽  
pp. 350
Author(s):  
Akemi Sawai ◽  
Risa Mitsuhashi ◽  
Yuki Warashina ◽  
Alexander Zaboronok ◽  
Ryota Sone ◽  
...  

1995 ◽  
Vol 132 (3) ◽  
pp. 357-362 ◽  
Author(s):  
M Tena-Sempere ◽  
L Pinilla ◽  
E Aguilar

Tena-Sempere M, Pinilla L, Aguilar E. Orchidectomy selectively increases follicle-stimulating hormone secretion in gonadotropin-releasing hormone agonist-treated male rats. Eur J Endocrinol 1995;132: 357–62. ISSN 0804–4643 The pituitary component of the feedback mechanisms exerted by testicular factors on gonadotropin secretion was analyzed in adult male rats treated with a potent gonadotropin-releasing hormone (GnRH) antagonist. In order to discriminate between androgens and testicular peptides, groups of males were orchidectomized (to eliminate androgens and non-androgenic testicular factors) or injected with ethylene dimethane sulfonate (EDS), a selective toxin for Leydig cells (to eliminate selectively androgens) and treated for 15 days with vehicle or the GnRH antagonist Ac-d-pClPhe-d-pClPhe-d-TrpSer-Tyr-d-Arg-Leu-Arg-Pro-d-Ala-NH2CH3COOH (Org.30276, 5 mg/kg/72 hours). Serum concentrations of luteinizing hormone (LH) and follicle-stimulating hormone (FSH) were measured 7 and 14 days after the beginning of treatment. We found that: in males treated with GnRH antagonist, orchidectomy or EDS treatment did not induce any increase in LH secretion; and orchidectomy, but not EDS treatment, increased FSH secretion in GnRH-treated males. The present results show that negative feedback of testicular factors on LH secretion is mediated completely through changes in GnRH actions. In contrast, a part of the inhibitory action of the testis on FSH secretion is exerted directly at the pituitary level. It can be hypothesized that non-Leydig cell testicular factor(s) inputs at different levels of the hypothalamic–pituitary axis in controlling LH and FSH secretion. Manuel Tena-Sempere, Department of Physiology, Faculty of Medicine, University of Córdoba, 14004 Córdoba, Spain


Sign in / Sign up

Export Citation Format

Share Document