THE METABOLISM OF PROSTAGLANDIN E2 BY TISSUES FROM THE HUMAN UTERUS AND FOETO-PLACENTAL UNIT

1978 ◽  
Vol 87 (3) ◽  
pp. 632-642 ◽  
Author(s):  
Eve A. Willman ◽  
W. P. Collins

ABSTRACT The biosynthesis and metabolism of prostaglandin E2 was studied in cell-free homogenates of tissues from the uterus and foeto-placental unit using specific in vitro methods. The results show that the synthesis of prostaglandin E2 is greater in endometrial tissue from the secretory phase (53.07 ± 39.05; ng/100 mg wet tissue/h) than from the proliferative phase of the uterine cycle. Furthermore, endometrial tissue forms more of this compound than myometrium (P < 0.005). During early pregnancy, synthesis is decreased (25.10 ± 16.62); at term, myometrium produces more prostaglandin E2 than decidua. During labour, however, decidual tissue accumulates more of this compound (52.73 ± 18.04) than either myometrium (34.71 ± 13.19) or cord (28.63 ± 11.71). The catabolic enzymes are most active in the placenta and chorion, followed by the cord, myometrium, decidua and amnion, but the differences have only a slight effect on the amounts of prostaglandin E2 which remain at the end of the incubation. The results suggest a high turnover of prostaglandin E2 in the decidua, myometrium and cord.

1974 ◽  
Vol 62 (1) ◽  
pp. 109-123 ◽  
Author(s):  
R. G. GABB ◽  
G. M. STONE

SUMMARY Human endometrial and myometrial tissues were incubated in vitro with [3H]oestradiol-17β and [3H]oestrone to study the uptake and interconversion of these two steroids by the tissues. Endometrial tissue displayed a higher capacity for oestrogen interconversion than myometrial tissue and the oxidation of oestradiol-17β to oestrone was favoured, rather than the reverse reaction. A greater degree of oxidation was found in tissue taken from uteri in the secretory phase than in the proliferative phase. A study of the distribution of radiometabolites between 'soluble' and 'particulate' fractions of tissue homogenates showed that a greater proportion of the tissue radioactivity was associated with the 'particulate' fraction in the proliferative phase than in the secretory phase. After incubation of endometrial tissue from the secretory phase with tritiated oestrogens there was evidence of the formation of chloroform-insoluble radiometabolites and some of these were tentatively identified as oestrogen sulphates. In a second experiment, the uptake and metabolism of the same two oestrogens by tissue from leiomyomata uteri (fibroids) and normal myometrial tissue were compared. No significant difference between these tissues was found. The results suggest that the levels of 17β-hydroxysteroid dehydrogenase in the human uterus may be dependent upon the levels of oestrogens in the blood. The lack of a difference in the treatment of oestrogens by fibroid and normal myometrial tissue suggests that these tissues may have a similar mechanism for the uptake and retention of oestrogens.


1975 ◽  
Vol 80 (4) ◽  
pp. 719-731 ◽  
Author(s):  
A. R. Krishnan ◽  
B. K. Bajaj ◽  
V. Hingorani ◽  
K. R. Laumas

ABSTRACT A study of the metabolism of oestradiol in the human endometrium and myometrium of the proliferative and secretory phases of the cycle showed that the conversion of oestradiol to oestrone by endometrium in the proliferative phase was higher than that in the secretory phase. The decreased metabolic activity of the secretory phase endometrium was attributed to the influence of progesterone on the endometrium. The metabolic conversion of oestradiol to oestrone was enhanced when pyridine nucleotides were added to the system. The conversion of oestradiol to oestrone was maximum in the cytoplasmic and nuclear fractions of the endometrium. Furthermore, the conversion of oestradiol was low in all the subcellular fractions of the myometrium as compared with the endometrial subcellular fractions. The presence of co-factors increased the metabolic conversion of oestradiol to oestrone in the subcellular fractions of the endometrium. The presence of 17β-hydroxysteroid oxidoreductase was indicated in all the subcellular fractions. A correlation was found between the amount of oestradiol and oestrone bound to the receptors in the uterus and the rate of metabolism of oestradiol in the uterus. The physiological significance of metabolism of oestradiol and the hormone action are discussed.


2010 ◽  
Vol 22 (1) ◽  
pp. 274
Author(s):  
K. C. Choi ◽  
E. B. Jeung

The endometrium is hostile to embryo implantation except during the window of receptivity. A change in endometrial gene expression is required for the development of receptivity. The uterine calcium balance is crucial for physiological functioning, including smooth muscle contraction and embryo implantation. The location of cytoplasmic calcium-related proteins (CRP) include the calcium transporters 1 (CaT1), calbindin-D9k/-D28k (CaBP- 9k/28k), plasma membrane Ca2+-ATPase 1b (PMCA1b), sodium/calcium exchangers (NCX1), and potassium-dependent Na+/Ca2+ exchanger (NCKX3). The expressions of these CRP and their potential roles in the uterus of human during the menstrual cycle remain to be clarified. Thus, in this current study, the expression patterns of CRP were examined for their roles in the human uterus during the menstrual cycle. Human endometrial tissues were collected by curettage from women undergoing hysteroscopy for investigation of tubal patency or tubal ligation. Approval was given by the Human Ethics Committee at SCH Medical Center, Bucheon, and signed consent was obtained in every case. Human uterus (total n = 51) were divided into 3 groups: menstrual, proliferative, and secretory phase. Reverse-transcription PCR and Western blot analysis were applied to measure the level of CRP mRNA and protein, respectively. During the menstrual cycle of human, the expression levels of CaT1 mRNA and protein were increased 5-fold at proliferative phase (Days 6 to 13) compared with secretory phase in the endometrium of uterus. The expression of CaBP-28k mRNA and protein was less 2-fold during the proliferative phase (Days 6 to 13) than during the secretory phase (Days 16 to 28). However, the expressions of NCX1, NCKX3, and PMCA1b mRNA and protein were not altered during cycle, whereas the expression of CaBP-9k was not observed in the uterus of human. In addition, spatial expression of CRP was detected by immunohistochemistry Uterine CRP was abundantly localized in the cytoplasm of the luminal and glandular epithelial cells during menstrual cycle. Taken together, these results indicate that uterine CRP is abundantly expressed in the uterus, suggesting that uterine expression of CRP might be involved in reproductive function during the menstrual cycle in human.


1973 ◽  
Vol 74 (3) ◽  
pp. 576-591 ◽  
Author(s):  
K. Murugesan ◽  
V. Hingorani ◽  
K. R. Laumas

ABSTRACT The human endometrium and the myometrium have the capacity to convert [6,7-3H]norethynodrel to norethindrone, 17α-ethynyl-3α,17β-dihydroxy-5-(10)-oestrene and two other unidentified metabolites. Under in vitro conditions, 80–90 % of 3H-norethynodrel was converted to its metabolites within 90 min. The metabolites formed were the same for both the endometrium and the myometrium. The amount of norethynodrel converted to its metabolites was more in the proliferative phase than in the secretory phase. Among the subcellular fractions of the myometrium, mitochondrial and microsomal fractions metabolised norethynodrel to norethindrone and two polar metabolites with low chromatographic mobility. In the myometrial 105 000 × g supernatant fraction, 17α-ethynyl-3α,17β-dihydroxy-5(10)-oestrene was formed in addition to norethindrone and the polar metabolites. The significance of the formation of norethindrone – a potent oral progestin as a product of the metabolism of norethynodrel and its possible action at the uterine level in the control of fertility is discussed.


Reproduction ◽  
2012 ◽  
Vol 143 (4) ◽  
pp. 531-538 ◽  
Author(s):  
Huan Yang ◽  
Yuping Zhou ◽  
Benjiamin Edelshain ◽  
Frederick Schatz ◽  
Charles J Lockwood ◽  
...  

FKBP4 (FKBP52) and FKBP5 (FKBP51) are progestin receptor (PR) co-chaperone proteins that enhance and inhibit, respectively, progestin-mediated transcription by PR. Here, we examinedFKBP4andFKBP5expression in the eutopic endometrium of fertile women with endometriosis and effects of FKBP4 and FKBP5 on the decidualization of human endometrial stromal cells (HESCs), and assessed HOXA10 regulation of FKBP4. Expression ofFKBP4mRNA was increased in the late proliferative phase and remained elevated throughout the secretory phase.FKBP5expression was low and remained constant throughout the menstrual cycle. Compared with controls,FKBP4mRNA expression was decreased in the endometrium of women with endometriosis, whereas no significant endometriosis-related change was seen forFKBP5. Cultured HESCs were treated with eitherFKBP4orFKBP5siRNA and then decidualized by incubation with progesterone (P4) and 8-bromoadenosine cAMP. Treatment of HESCs withFKBP4siRNA resulted in 60% lowerIGFBP1expression. In contrast, incubation withFKBP5siRNA did not significantly decreaseIGFBP1expression duringin vitrodecidualization.HOXA10andFKBP4expression increased in parallel duringin vitrodecidualization. In HESCs, overexpressed HOXA10 enhanced FKBP4 mRNA and protein levels, whereas HOXA10 knockdown decreased FKBP4 mRNA and protein levels compared with controls. Similarly, duringin vitrodecidualization,FKBP4expression was decreased in HOXA10-silenced cells. EnhancedHOXA10expression in HESCs elicits a decidualization mediating increase inFKBP4expression. The findings are consistent with the observation that women with endometriosis have diminishedFKBP4expression leading to impaired decidualization and infertility. The P4resistance seen in endometriosis may be mediated through HOXA10-regulatedFKBP4expression.


1978 ◽  
Vol 77 (3) ◽  
pp. 361-371 ◽  
Author(s):  
J. B. MAATHUIS ◽  
R. W. KELLY

The concentrations of prostaglandins F2α (PGF) and E2 (PGE) were measured by gas chromatography–mass spectrometry in endometrial tissue obtained from 45 normal women at various stages of the menstrual cycle. During the proliferative stages, the concentration of PGF in the endometrium was correlated with the concentration of oestradiol in the plasma. The concentration of PGF during the mid-secretory stage (mean, 2·047, range, 0·549–4·344 μg/g fresh endometrial tissue) was significantly higher than the concentrations during the late proliferative and late secretory stages. The endometrial concentration of PGE did not show a cyclic variation. The concentrations of PGF and PGE in samples of endometrium collected after the administration of clomiphene were significantly lower than the concentrations observed in endometrial tissue obtained from normally menstruating women in the mid-proliferative period. The administration of an oestrogen–progestogen pill resulted in higher endometrial concentrations of PGE than were measured in the mid-secretory phase. The concentrations of PGF and PGE in decidual tissue (conceptual age 3–10 weeks) were lower than those measured at any stage of the normal menstrual cycle. During the human menstrual cycle, high levels of oestradiol and progesterone are related to high endometrial levels of PGF but not PGE. The presence of a conceptus apparently blocks the effect of high concentrations of ovarian steroids on the synthesis or catabolism of prostaglandins.


1975 ◽  
Vol 78 (2) ◽  
pp. 353-363 ◽  
Author(s):  
C. B. Lunan ◽  
B. Greenz

ABSTRACT Specimens of endometrium from the vault, body and lower body regions of the same human uteri were incubated separately for 30 min in vitro in the presence of 1–6 × 10−9m 3H-oestradiol. Uptake into the nuclei was variable but in general the vault region endometrium was least active in nuclear accumulation of the hormone, especially in secretory phase endometrium. This suggests that intra-uterine variations found in oestradiol uptake in vivo are due to regional differences in the state of the tissue itself.


Author(s):  
A. Gonzalez Angulo ◽  
R. Berlioz ◽  
R. Aznar

Recent ultrastructural studies on endometrial tissues from women wearing copper, wire intrauterine devices have disclosed morphological evidence of impaired glycogen degradation and secretion resulting in interference with the viability of blastocysts. Reduced microapocrine secretion observed with the scanning electron microscope supports this (1). In addition, organelle modifications have been observed in the epithelial cells of these women. The changes are seen in biopsies taken in the proliferative phase of the cycle and consist of mitochondrial vacuolation and myelin figure formation. These modifications disappear in the secretory phase and therefore have been regarded as reversible (2).The aim of the present studies was to investigate surface epithelial changes as well as organelle modifications in relation to the site of contact with an IUD that releases greater amounts of copper. Endometrial tissue was obtained from the uterine cavity of four young women wearing TCu-380-A intrauterine contraceptive devices for 4-6 weeks.


1994 ◽  
Vol 111 (3) ◽  
pp. 189-196 ◽  
Author(s):  
C SNYDERMAN ◽  
I KLAPAN ◽  
M MILANOVICH ◽  
D HEO ◽  
R WAGNER ◽  
...  

1967 ◽  
Vol 54 (4) ◽  
pp. 645-662 ◽  
Author(s):  
Å. Hjalmarson ◽  
K. Ahrén

ABSTRACT The effect of growth hormone (GH) in vitro on the rate of intracellular accumulation of the non-utilizable amino acid α-aminoisobutyric acid (AIB) was studied in the intact rat diaphragm preparation. Bovine or ovine GH (25 μg/ml incubation medium) markedly stimulated the accumulation of AIB-14C by diaphragms from hypophysectomized rats, while there was no or only a very slight effect on diaphragms from normal rats. In diaphragms from rats with the pituitary gland autotransplanted to the kidney capsule GH in vitro stimulated the accumulation of AIB-14C significantly more than in diaphragms from normal rats but significantly less than in diaphragms from hypophysectomized rats. Injections of GH intramuscularly for 4 days to hypophysectomized rats made the diaphragms from these rats less sensitive or completely insensitive to GH in vitro. These results indicate strongly that the relative insensitivity to GH in vitro of diaphragms from normal rats is due to the fact that the muscle tissues from these rats has been exposed to the endogenously secreted GH. The results show that GH can influence the accumulation of AIB-14C in the isolated rat diaphragm in two different ways giving an acute or »stimulatory« effect and a late or »inhibitory« effect, and that it seems to be a time-relationship between these two effects of the hormone.


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