Myometrial tissues from pregnant and nonpregnant mature and immature rats were examined for the presence of gap junctions by thin section and freeze-fracture microscopy before and after incubation in vitro. Gap junctions were not present in any tissues fixed in situ or shortly after removal from animals. The junctions were present in tissues incubated for 2 h in vitro, and the number and size of the junctions increased with increasing incubation times up to 48 h. Tissues from immature rats incubated in vitro formed gap junctions in much reduced numbers as compared to tissues from pregnant or nonpregnant mature animals. Injection of immature animals with estrogen with or without progesterone, but not with progesterone alone, increased the number of gap junctions found in tissues when incubated in vitro. In vitro treatment of tissues from immature animals with estrogen also stimulated the formation of gap junctions. Progesterone treatment in vitro had no effect on gap junction formation in any myometrial tissues. However, progesterone added in vitro in the presence of estrogen decreased the number of gap junctions as compared to the numbers formed with addition of estrogen alone in treated tissues from immature or pregnant animals. The addition of indomethacin 5,8,11,14-eicosatetraynoicacid and arachidonic acid partially inhibited the formation of gap junctions in tissues from pregnant animals incubated in vitro. A stable endoperoxide of PGH2 and arachidonic acid, but not PGE1, PGE2, PGF(2α), or thromboxane β2, overcame the inhibition of gap junction formation produced by indomethacin. These results are consistent with the hypothesis that steroid hormones and prostaglandin interact to modulate gap junction formation in the myometrium.
myometrial gap junction formation estrogen progesterone, gap junctions uterine smooth muscle steroid hormones, Garfield RE myometrium gap junctions prostaglandins, estrogen stimulation gap junction formation rat myometrium, progesterone inhibition estrogen-induced gap junctions, prostaglandin endoperoxide gap junction modulation, indomethacin inhibition myometrial gap junctions, cell-to-cell communication myometrium pregnancy labor, freeze fracture microscopy myometrial gap junctions, steroid hormone prostaglandin interaction uterine contractility
PMID 7369350 7369350 DOI 10.1152/ajpcell.1980.238.3.C81 10.1152/ajpcell.1980.238.3.C81 Garfield et al. 1980, Garfield 1980
Cite this article
Garfield, R. E., Kannan, M. S., & Daniel, E. E. (1980). Gap junction formation in myometrium: control by estrogens, progesterone, and prostaglandins. The American journal of physiology, 238(3), C81-C89. https://doi.org/10.1152/ajpcell.1980.238.3.C81
Garfield RE, Kannan MS, Daniel EE. Gap junction formation in myometrium: control by estrogens, progesterone, and prostaglandins. Am J Physiol. 1980;238(3):C81-C89. doi:10.1152/ajpcell.1980.238.3.C81
Garfield, R. E., et al. "Gap junction formation in myometrium: control by estrogens, progesterone, and prostaglandins." The American journal of physiology, vol. 238, no. 3, 1980, pp. C81-C89.
Bouchard TP et al., 2026·Journal of ovarian research·
Open Access
Reproductive hormones of the fertile window are often referenced to women in regular cycles, but this may not be representative of the hormonal profiles of women in different circumstances like polycystic ovarian syndrome, the postpartum period, and the perimenopause transition. This observational cohort study sought to identify the variability in the reproductive hormones in various clinical circumstances and to establish potential thresholds for each category based on hormone measurements with the Mira urinary hormone monitor. A total of 57 women (ages 22-51) in various circumstances (regular cycles, polycystic ovarian syndrome, postpartum and perimenopause) tracked Mira urine hormone measurements (estrone-3-glucuronide, luteinizing hormone, pregnanediol glucuronide), contributing 444 cycles of data. Using additive mixed models, hormone values were stratified by the four different reproductive categories. The perimenopause and polycystic ovarian syndrome groups demonstrated relative hypoestrogenic states, while the perimenopause group showed low luteal pregnanediol glucuronide and the polycystic ovarian syndrome/polyendocrine metabolic ovarian syndrome (PCOS/PMOS) group showed high luteal pregnanediol glucuronide. The perimenopause group had significantly higher luteinizing hormone values throughout the whole cycle. The fertile window hormone thresholds vary depending on a woman's specific reproductive category. Women in different circumstances should not necessarily use the same hormonal thresholds for the fertile window and ovulation. A larger dataset with ultrasound correlation to ovulation is required to delineate the fertile window with more precision. Hormone differences across the menstrual cycle could be used for targeted treatments in polycystic ovarian syndrome and perimenopause women.
Anti-Müllerian hormone (AMH), produced by ovarian granulosa cells, is a key regulator of female reproduction. Traditionally seen as a local follicular brake, emerging evidence calls for a paradigm shift. We propose that AMH acts as a context-dependent signaling hub. It primarily signals via the Smad1/5/8 pathway and interacts with Wnt/β-catenin and MAPK cascades to regulate follicle growth and steroidogenesis. Beyond the ovary, AMH and its receptors are expressed in the hypothalamus, pituitary, uterus, and placenta, modulating the hypothalamic-pituitary-gonadal axis and other reproductive processes. This review provides a comprehensive framework for understanding AMH as a context-dependent signaling hub in female mammals.
Sajjad MU et al., 2026·Archives of gynecology and obstetrics
The human placenta consumes, on average, one third of the glucose from maternal blood. However, the role of placental glucose consumption in the production of estradiol and progesterone remains unclear. We hypothesized that placental glucose consumption in humans is associated with steroid production via a non-glycolytic pathway. We included 41 healthy pregnancies at term. Blood samples were obtained from the maternal radial artery, uterine vein, and from the umbilical artery and vein during scheduled cesarean delivery. Blood flow in the uterine artery and umbilical vein was measured using Doppler ultrasound. Plasma concentrations of estradiol, progesterone, glucose, insulin, lactate, and ketones were analyzed. We calculated uteroplacental uptake and consumption of maternal glucose and ketones, and the loss of uteroplacental lactate in 6-carbon units as well as the release of steroid hormones into maternal circulation. Our data revealed a net placental release of estradiol and progesterone into maternal circulation [24.1 (5.34, 49.8) and 560.3 (61.2, 798.2) nmol/min, respectively]. The release of estradiol was positively associated with uteroplacental glucose uptake (ρ = 0.59, p < 0.001) and consumption (ρ = 0.43, p = 0.005), while progesterone exhibited similar associations (ρ = 0.61, p < 0.001; ρ = 0.43, p = 0.005). Notably, both hormones correlated positively with lactate-adjusted uteroplacental glucose consumption but not with acetate-equivalent uteroplacental ketone consumption. Placental release of estradiol and progesterone correlates with uteroplacental consumption of glucose that primarily occurs via non-glycolytic pathways in the third trimester placenta.
Valenti M et al., 2026·Am J Obstet Gynecol·
Open Access
Endometriosis is a chronic, gynecologic condition in which tissue similar to the lining of the uterus implants throughout the body. Women with endometriosis have a higher prevalence of infertility and a greater risk of early natural menopause compared to those without endometriosis. This study aimed to evaluate preoperative serum AMH levels among women with and without incident endometriosis and to assess whether levels differ by surgical staging and typology. The ENDO (Endometriosis: Natural History, Diagnosis, and Outcomes) study was conducted between 2007 and 2009. The ENDO study consisted of an operative and population cohort (n=600). Only those in the ENDO operative cohort from the Utah site were used for this analysis, and included women aged 18 to 44 years who were scheduled for gynecologic surgery, irrespective of clinical indication (n=476). AMH levels were measured from stored serum collected before surgery using a quantitative enzyme-linked immunosorbent assay. After excluding participants with missing outcome data (n=51), unilateral oophorectomy (n=8), or those within the population cohort (n=69), 348 participants remained for the analysis. Surgically confirmed endometriosis diagnosis, staging (American Society for Reproductive Medicine I-IV), and typology (superficial, deep, ovarian) were ascertained by the operative report. Outliers for AMH (>14.0 ng/mL) were excluded from the analyses and AMH values were log-transformed. Multivariable linear regression models adjusted for age (squared and continuous), body mass index, serum cotinine levels, and exogenous hormonal contraceptive use were conducted. Percentage differences in AMH were calculated as (exp[β]-1)×100, and 95% confidence intervals were reported. Compared with no endometriosis, incident endometriosis diagnosis was associated with lower AMH levels (-19.8%; 95% confidence interval, -37.0 to 1.0); however, this association was not statistically significant. Stage III to IV disease was associated with 40.1% lower AMH levels (95% confidence interval, -58.9 to -12.7). Ovarian endometriomas were most strongly associated with lower AMH levels (-54.3%; 95% confidence interval, -69.4 to -31.8), with a more pronounced association among those with infertility (-72.6%; 95% confidence interval, -85.4 to -48.5). Deep (-24.1%; 95% confidence interval, -48.2 to 11.0) and superficial (-15.5%; 95% confidence interval, -34.6 to 9.3) endometriosis also showed a trend toward lower AMH levels, but these findings were not statistically significant. Compared with a postoperative diagnosis of a normal pelvis, incident endometriosis was associated with 26.8% lower AMH levels (95% confidence interval, -44.6 to -3.4). Stage III to IV disease was associated with 47.8% lower AMH levels (95% confidence interval, -65.8 to -23.2), and all subtypes of endometriosis were statistically significantly associated with lower levels of AMH compared with a postoperative diagnosis of a normal pelvis (ovarian: -60.8%; 95% confidence interval, -74.4 to -39.9; deep: -34.3%; 95% confidence interval, -56.2 to -1.4; superficial: -24.8%; 95% confidence interval, -43.9 to -0.8). Ovarian and moderate to severe (stage III-IV) endometriosis were associated with markedly lower AMH levels compared with no endometriosis. Compared with a postoperative diagnosis of a normal pelvis, incident endometriosis and moderate to severe stages (stage III-IV) were associated with statistically significantly lower AMH levels. Additionally, typology (deep, ovarian, or superficial) was associated with statistically significantly lower AMH levels. However, this association was likely driven by the presence of ovarian endometriomas across all subtypes. These findings are consistent with previous studies and demonstrate that endometriosis lesions themselves, independent of surgical intervention, influence AMH levels.