PROGESTERONE IN THE UTERUS

1974 ◽  
Vol 77 (1) ◽  
pp. 160-170 ◽  
Author(s):  
D. Egert ◽  
H. Maass
Keyword(s):  
Extracellular Fluid ◽  
Uterine Tissue ◽  
Rat Uterus ◽  
Pregnant Rats ◽  
Pregnant Rat

ABSTRACT Radio-metabolites of progesterone and progesterone itself were found in the uteri of intact pregnant rats 20 min after injection of [1,2-3H]progesterone. However, after evisceration and removal of the foeto-placental unit, and following injection of the labelled steroid, the progesterone content in the extract from the pregnant rat uterus markedly increased while the metabolite levels correspondingly decreased. An analogous change was observed in the plasma. Thus it appears probable that progesterone is not metabolized in the uterus of pregnant rats, and that metabolites found in this tissue originate predominantly in the foetoplacental system and appear in the plasma and extracellular fluid present in the uterine tissue.

METABOLISM OF 20β-HYDROXY-4-PREGNEN-3-ONE IN UTERINE TISSUE OF NON-PREGNANT RATS IN VITRO

1976 ◽  
Vol 83 (3) ◽  
pp. 604-620 ◽  
Author(s):  
B. P. Lisboa ◽  
M. Holtermann
Keyword(s):  
Biological Activity ◽  
Adult Female ◽  
Female Rats ◽  
Uterine Tissue ◽  
Rat Uterus ◽  
Adult Rats ◽  
Pregnant Rats ◽  
Progesterone Metabolites ◽  
Ovariectomized Adult Rats

ABSTRACT In vitro experiments carried out with uterus preparations of ovariectomized adult rats indicate the presence in this tissue of a 20β-hydroxysteroid-oxidoreductase which catalyzes the conversion of 20β-hydroxy-4-pregnen-3-one to progesterone. Since a hepatic 20β-hydroxysteroid-oxidoreductase is absent in adult female rats, the myometrial enzyme can be responsible for the biological activity of 20β-hydroxy-4-pregnen-3-one in these animals. Besides progesterone five metabolites were isolated and identified after incubation of [4-14C]20β-hydroxy-4-pregnen-3-one with uterine tissue: 20β-hydroxy-5α-pregnan-3-one, 20β-hydroxy-5β-pregnan-3-one, 5α-pregnane-3α,20β-diol, 4-pregnene-3α,20β-diol and 4-pregnene-3β,20β-diol. The conversion of 20β-hydroxy-4-pregnen-3-one to progesterone permits us to regard all five steroids isolated as progesterone metabolites in the rat uterus. 20β-hydroxy-5β-pregnan-3-one is the first C21-metabolite with a 5β(H)-configuration isolated in the rat uterus, which indicates the presence of 5β-reductase in this tissue.

scholarly journals Hyperlipidemia impairs uterine β-adrenergic signaling by reducing cAMP in late pregnant rats

Reproduction ◽  
2020 ◽  
Vol 159 (1) ◽  
pp. 49-58 ◽  
Author(s):  
Sakshi Chauhan ◽  
Subhashree Parida ◽  
E Prakash ◽  
G Srinivasan ◽  
Vivek Srivastava ◽  
...  
Keyword(s):  
High Cholesterol Diet ◽  
High Fat ◽  
Rat Uterus ◽  
Pregnant Rats ◽  
Camp Content ◽  
Pregnant Rat ◽  
Adrenergic Signaling ◽  
Adrenoceptor Agonist ◽  
Gi Protein ◽  
Tension Experiments

The aim of the present study was to reveal the effect of hyperlipidemia on β2- and β3-adrenergic signaling in late pregnant rat uterus. Hyperlipidemia was induced in female Wistar rats by feeding a high-fat high-cholesterol diet for 8 weeks before and after mating upto the 21st day of gestation. The effect of hyperlipidemia on β-adrenergic signaling was studied with the help of tension experiments, real-time PCR and cAMP ELISA in 21-day pregnant rat uterus. In tension experiments, hyperlipidemia neither altered the spontaneous contractility nor the oxytocin-induced contractions. However, it decreased the −logEC50 values of β2-adrenoceptor agonist, salbutamol and β3-adrenoceptor agonist, BRL37344. It also decreased the efficacy of adenylyl cyclase activator, forskolin. Further, there was a significant decrease in salbutamol and BRL37344-stimulated cAMP content in uterine tissues. However, there was no alteration in mRNA expressions of β2-adrenoceptor (Adrb2), β3-adrenoceptor (Adrb3) and Gs protein (Gnas) though there was a significant increase in the mRNA expression of Gi protein (Gnai). In conclusion, reduced cAMP content after beta-adrenergic receptor stimulation, which correlates with an increase in Gnai mRNA, may explain the mechanism of the impairment of uterine β-adrenergic signaling in hyperlipidemic pregnant rats. The clinical implication of the present study may relate to reduced myometrial relaxant response to β-adrenergic agonists in high fat-induced uterine dysfunction.

Salt saving in the pregnant rat

1961 ◽  
Vol 201 (5) ◽  
pp. 765-768 ◽  
Author(s):  
I. J. Lichton
Keyword(s):  
Saline Solution ◽  
Isotonic Saline ◽  
Extracellular Fluid ◽  
Sodium Content ◽  
Sodium Balance ◽  
Sodium Retention ◽  
Pregnant Rats ◽  
Pregnant Rat ◽  
Near Term ◽  
Total Sodium

Pregnant rats of two strains showed average net accumulation of approximately 83 mEq of sodium/kg of weight gain throughout gestation. Of the total sodium retention, 15, 23, and 62% occurred in each successive third of gestation. Analysis of postpartum sodium balance and of fetal sodium content at term indicated that there was no net accumulation of sodium in the tissues of the dams. Near term, rats given isotonic saline solution showed diminished ability to excrete the administered water in the urine, but showed no impairment in sodium excretion. Serum sodium concentrations were slightly decreased and serum osmolalities were significantly decreased in comparison to values for nonpregnant rats. At term the pregnant rats had greater extracellular fluid volumes than did nonpregnant controls.

scholarly journals Incorporation of [3H] uridine into the ribonucleic acid of rat uterus during pseudopregnancy and in the presence of I.C.I. 46474 [trans-1-(p-β-dimethylaminoethoxyphenyl)-1,2-diphenylbut-1 -ene]

1970 ◽  
Vol 119 (4) ◽  
pp. 609-613 ◽  
Author(s):  
J. E. O'Grady ◽  
P. J. Heald ◽  
Anne O'Hare
Keyword(s):  
Ribonucleic Acid ◽  
Untreated Control ◽  
Rna Synthesis ◽  
Uterine Tissue ◽  
Rat Uterus ◽  
Pregnant Rat ◽  
Uridine Incorporation ◽  
Important Requirement ◽  
Dose Concentration ◽  
Different Doses

1. The incorporation of [3H]uridine into RNA of rat uterine tissue has been measured during pseudopregnancy and in rats receiving different doses of an anti-implantation compound [trans-1-(p-β-dimethylaminoethoxyphenyl)-1,2-diphenylbut- 1-ene, I.C.I. 46474]. 2. In the uterus of the pseudopregnant rat uridine incorporation into RNA increased markedly on day 3 of pseudopregnancy, remained high until day 5 and decreased sharply by day 6, rising again by day 9. 3. This pattern of change was similar to, but not identical with, that previously found in the pregnant rat. 4. Rats receiving I.C.I. 46474 at a dose concentration below that preventing implantation showed a pattern of RNA synthesis similar to that found in untreated control rats. 5. Rats treated with doses of I.C.I. 46474 sufficient to inhibit implantation revealed a totally different pattern of incorporation of [3H]uridine into uterine RNA. 6. The results are discussed in terms of previous findings with the normally pregnant rat. It is concluded that the increasing uterine RNA synthesis found on day 3 in the pregnant rat is an important requirement for the occurrence of the subsequent implantation.

Immunohistochemical Localization of Cyclooxygenase-2 in Pregnant Rat Uterus by Sp-6 Acupuncture

2003 ◽  
Vol 31 (03) ◽  
pp. 481-488 ◽  
Author(s):  
Jeong-Sang Kim ◽  
Chang Su Na ◽  
Woo Jun Hwang ◽  
Byung Chul Lee ◽  
Ki Hyoung Shin ◽  
...  
Keyword(s):  
Acupuncture Treatment ◽  
Immunohistochemical Localization ◽  
Cyclooxygenase 2 ◽  
Uterine Contractility ◽  
Rat Uterus ◽  
Pregnant Rats ◽  
Pregnant Rat ◽  
Complementary Method ◽  
Key Factor ◽  
Cox 2

As pregnancy advances, prostaglandins (PG) increase in the uterus, leading to elevated uterine contractility. Therefore, regulating the concentration of PG in the uterus can be a key factor for controlling the duration of labor. Since the synthesis of PGs in the uterus is catalyzed by cyclooxygenase-2 (COX-2), devising a tool to regulate the expression of COX-2 could provide a method for treating complicated labor. In this study, Sp-6 acupuncture treatment was evaluated for its potential in controlling uterine motility. Immunohistochemical methods showed the COX-2 enzyme was primarily found in the endometrium and myometrium of rat uterus. COX-2 expression in these two locations were intensified by pregnancy, but reduced by acupuncture at the Sp-6 acupoint. Uterine motility monitored during Sp-6 acupuncture was reduced by 28.15% (p < 0.05) and 19.88% (p < 0.05) in pregnant rats and non-pregnant rats, respectively. The significant reduction of uterine motility in pregnant rat suggests a role for Sp-6 acupuncture in regulating the expression of COX-2 during pregnancy. These results suggest that Sp-6 acupuncture could be used as a complementary method for controlling labor in human pregnancy.

scholarly journals PEPTIDOGLYCAN OF STAPHYLOCOCCUS AUREUS ALTERS THE MYOMETRIAL CONTRACTILITY OF NON-PREGNANT RATS TROUGH INCREASING INTRACELLULAR CALCIUM LEVELS

2020 ◽  
Vol 66 (6) ◽  
pp. 56-65
Author(s):  
L.S. Nasibian ◽  
◽  
H.V. Sotkis ◽  
O.M. Tzugorko ◽  
I.B. Philippov ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Calcium Ions ◽  
Rat Uterus ◽  
Pregnant Rats ◽  
Pregnant Rat ◽  
Relaxation Phase ◽  
Intracellular Content ◽  
Long Time ◽  
Myometrial Contractility ◽  
Spontaneous Contractions

The work is devoted to the study of the effect of Staphylococcus aureus peptidoglycan on the main parameters of myometrial contractions and the mechanism of this influence. The research was carried out by tensometry and calcimetry methods. The results of the experiments demonstrated that peptidoglycan modulates all the main parameters of contractions of the non-pregnant rat uterus, including increasing their amplitude and duration by 10 and 30%, respectively, mainly by prolonging the relaxation phase (56.7 ± 1.6%): myometrial band relative to quickly shrunk and relaxed for a long time. Application of peptidoglycan on freshly isolated uterine myocytes for 5 min led to a periodic increase in their intracellular content of calcium ions. Peptidoglycan enhanced myometrial contractions caused by hyperpotassium solution at a concentration of 60 mmol. Administration of 1 μmol of nifedipine, a blocker of potential-directed L-type calcium channels, suppressed spontaneous contractions enhanced by peptidoglycan. These changes in myometrium contractility of on the background of peptidoglycan action occur not only due to increased transmembrane calcium intake, but also its mobilization from the sarcoplasmic reticulum.

Prolonged stretching in the late-late pregnant rat uterus inhibits contractions through potassium channel TREK-1

2020 ◽  
Author(s):  
Zongzhi Yin ◽  
Yun Li ◽  
Dan Li ◽  
Jingjing Su ◽  
Bing Shen ◽  
...  
Keyword(s):  
Arachidonic Acid ◽  
Potassium Channel ◽  
Isometric Contraction ◽  
Late Pregnancy ◽  
Rat Uterus ◽  
Pregnant Rats ◽  
Pregnant Rat ◽  
Pregnant Uterus ◽  
Myometrial Contractility

Abstract Background Prolonged stretching can inhibit myometrial contractions in the nonpregnant and the mid- and late-term pregnant uteri of rats and humans through potassium channel TREK-1. What happens in the pregnant uterus close to parturition remains unknown. Methods Uterine tissues from late-late pregnant rats (day 20–21 of pregnancy) were isolated, and myometrial strips were prepared for isometric contraction measurements. We compared the oxytocin-induced contractions of myometrial strips treated with different stretch times and doses. Then, we used the potassium channel TREK-1 inhibitor L-methionine and TREK-1 agonist arachidonic acid to determine whether the changes caused by prolonged stretching involved changes in TREK-1 activity. Results Prolonged stretching caused relaxation of the myometrial strips that were close to parturition. Additionally, TREK-1 inhibition partly reversed the myometrial relaxation caused by prolonged stretching of the late-late pregnant rat uterus, while TREK-1 activation resulted in a dramatic myometrial contraction change. Conclusions Prolonged stretching can inhibit myometrial contractility and induce myometrial relaxation in late-late pregnancy. This contractile inhibition is partly due to functional upregulation of potassium channel TREK-1.

PLASMA PROLACTIN AND PROGESTERONE RESPONSES TO MATING ARE ALTERED IN AGED RATS

1981 ◽  
Vol 90 (2) ◽  
pp. 179-191 ◽  
Author(s):  
S. HENDRICKS ◽  
C. A. BLAKE
Keyword(s):  
Plasma Concentrations ◽  
External Jugular Vein ◽  
Female Rats ◽  
Plasma Prolactin ◽  
Aged Rats ◽  
Pregnant Rats ◽  
Pregnant Rat ◽  
Plasma Progesterone ◽  
The One ◽  
The Right

The effects of varying amounts of copulatory stimulation on patterns of plasma concentrations of prolactin and progesterone were evaluated in 3- and 12-month-old female rats. The 12-month-old group included rats which still exhibited oestrous cycles and rats in persistent vaginal oestrus (PVO). The extent of copulatory stimulation was defined by the number of intromissions received during mating: ≤5,15 or > 50. Blood samples were drawn over the 8 days after mating through a cannula inserted into the right external jugular vein. Plasma from the samples was assayed for prolactin and progesterone. In aged but still cyclic rats, pregnancy rates were positively correlated with the number of intromissions received during mating. Only one rat in PVO became pregnant. All animals which became pregnant and rats in PVO which, after mating, exhibited a disruption of the pattern of PVO, showed the nocturnal surge of plasma prolactin characteristic of pregnant and pseudopregnant rats. While these surges persisted until day 8 after mating in pregnant animals, they were absent by this time in the rats in PVO. Prolactin surges were present in some but not all of the aged rats which did not become pregnant. Progesterone concentrations were raised in all pregnant animals except the one pregnant rat in PVO and, while not related to the number of intromissions, concentrations were higher 8 days after mating in young compared with those in aged pregnant rats. Plasma progesterone was low in rats in PVO regardless of disruption of the pattern of PVO. We have concluded that the failure of limited copulatory stimulation to induce pregnancy in older rats results, at least in part, from its failure to initiate nocturnal prolactin surges. Nevertheless, our data suggest that matings which are not experimentally limited should provide ample stimulation to establish such surges. Although reduced plasma concentrations of prolactin and progesterone at pro-oestrus and reduced plasma progesterone through part of gestation may contribute to decreasing fertility in aged rats, other unidentified factors appear to be involved in mediating the capacity of extensive copulatory stimulation to induce pregnancy in these animals.

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