• The Korean Journal of Physiology
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• v.21 no.1
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• pp.35-46
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• 1987

It has been well known that estrogens stimulate the uterine contractility and progestins inhibit it. Then, one may expect that the uterine contractility and sensitivities to oxytocin (OT) and prostaglandin $F_{2{\alpha}}\;(PGF_{2{\alpha}})$ would be different among the estrus cycle. These hypotheses were tested using the mature female rat. Spontaneous isometric contractions of isolated uterine strips $(1{\times}0.3\;cm)$ from cyclic rats in various stages of the estrus cycle, bilateral ovarectomized rats and hypophysectomized rats were recorded in absence or presence with $estradiol-17{\beta}\;(E_2)$, progesterone $(P_4)$, OT and $PGF_{2{\alpha}}$. The results were summarized as follows: 1) The spontaneous uterine contractile force was the highest in the estrus rat and the lowest in the ovarectomized or the hypophysectomized rat. In the proestrus rat, the contractile frequency was the lowest (2.7 beats/10 min) and the contractile duration was the longest (70 sec). In the other groups, there were no any differencies in frequency (9 beats/10 min) and in duration (30 sec). 2) OT and $PGF_{2{\alpha}}$ stimulated the uterine contractility in all groups tested except in the hypophysectomized rat in which OT failed to stimulate the uterine contraction. $PGF_{2{\alpha}}$ was more effective in stimulating the uterine contraction than OT in all groups tested except in the estrus rat. OT-induced contraction was the highest in the estrus rat and $PGF_{2{\alpha}}-induced$ contraction was the lowest in the hypophysectomized rat. 3) Uterine contractilities were not changed by the in vitro treatments of $E_2$ or $P_4$ under the influence of endogenous steroids, however, $E_2$ and $P_4$ stimulated the uterine contraction in the ovarectomized rat in which endogenous steroids were almost abolished. 4) Increased uterine contraction by the treatment of OT was suppressed by in vitro $E_2$ or $P_4$ in the estrus rat, while it was potentiated by the $P_4$ in the proestrus rat. In other groups, exogenous $E_2$ or $P_4$ did not affect the OT-induced uterine contraction. 5) $PGF_{2{\alpha}}-induced$ uterine contraction was suppressed in the ovarectomized rat by $E_2$ and $P_4$, in the diestrus and proestrus rats by $P_4$ and in the hypophysectomized rat by $E_2$. In other groups, exogenous $E_2$ or $P_4$ was ineffective in altering the $PGF_{2{\alpha}}-induced$ uterine contraction. According to the above results, it may conclude that the mechanisms of the different uterine contractility and the different uterine sensitivity to OT or $PGF_{2{\alpha}}$ according to the estrus cycle are not explicable with only the serum concentrations of steroids, OT and $PGF_{2{\alpha}}$ but also other unknown factors.

• The Korean Journal of Physiology and Pharmacology
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• v.9 no.3
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• pp.165-172
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• 2005

The aim of this study was to determine the roles of ET-1 and NO on uterine blood flow in pregnancy. Uterine arteries were isolated from 17 nonpregnant and 12 pregnant women. Nonpregnant group included patients with median age of $48.6{\pm}2.3$ years who underwent hysterectomy, because of myoma. Pregnant group included patients with median age of $31.3{\pm}1.4$ years undergoing cesarean delivery. ET-1 and ET-2 induced concentration-dependent contraction in isolated nonpregnant and pregnant uterine arteries. The contractile response and maximal contraction were increased in pregnant uterine arteries. In nonpregnant uterine arteries, there was no contraction in response to ET-3, whereas pregnancy induced concentration-dependent contraction by ET-3. Tissue nitrite/nitrate level and immunohistochemical staining of eNOS and iNOS were increased in pregnant uterine arteries, compared with nonpregnant uterine arteries. In addition, the expressions of eNOS and iNOS mRNA were significantly increased in pregnancy. Moreover, contractions by ET isopeptides, including ET-1, were enhanced, and immunohistochemical staining of ET-1 and ET-1 mRNA expression was increased in pregnant uterine arteries. These results suggest that NO production by increased NOS activity, especially eNOS activity, is related to placental and uterine blood flow. Furthermore, ET-1 appears to play a pathophysiological role in pregnant complications such as hypertension.

• Women's Health Nursing
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• v.8 no.4
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• pp.538-549
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• 2002

This study was designed to test the effects of a full body massage on uterine contraction, length of labor, type of delivery, and drug intervention for primipara during labor. Data were collected using a quasi-experiment method (nonequivalent control group, pre-post test design) from November 1, 2001 to July 31, 2002. The subjects of this experiment consisted of 28 women in the experimental group and 29 in the control group, out of 57 primipara hospitalized at the U OB & GYN hospital in Inchon. The experimental group was given a 20 minute full body massage for each of the three delivery phases (latent, active, and transition). The control group was given conventional delivery care. Three (3) parameters were analyzed in this experiment. (1) The interval, duration, and strength of uterine contraction, using an electric tocodynamometer (2) The elapsed time for stage 1 and stage 2 labor. (3) The types of deliveries and drug interventions, using postpartum medical records The data collected were analyzed using the repeated measures analysis of variance (ANOVA), t-test, and $x^2$ test of the SPSS program. The results of the experiment are as follows: 1) Uterine contraction interval was significantly reduced (F=3.210, p=.050). Duration of uterine contraction showed significant increase only during the transition phase (t=-2.319, p=.023). Strength of uterine contraction showed no significant difference. 2) Total length of labor was significantly shortened (t=-5.245, p=.000). The length of 1st stage labor was significantly shortened (t=-5.164, p=.000), with latent phase showing (t=-4.709, p=.000), active phase (t=-2.973, p=.005), and transition phase (t=-2.031, p=.047). The length of 2nd stage labor showed no significant difference. 3) The number of natural deliveries were significantly increased ($x^2$=13.127, p=.004). 4) The number of drug interventions were significantly fewer ($x^2$= 4.493, p=.034). In conclusion, this study shows that a full body massage has a significantly positive effect on uterine contraction interval, length of labor, type of delivery, and drug intervention. Therefore, this study suggests that a full body massage be used clinically to help primipara during labor.

• The Journal of Korean Obstetrics and Gynecology
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• v.18 no.4
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• pp.72-84
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• 2005

Purpose : This study was carried out to investigate the relaxational response to the water extract of Sobokchukeo-Tang(SCT) in isolated uterine muscle in rats. Methods : Segments of uterine muscle obtained from female rats immediately after delivery were mounted in organ baths superfused on a polygraph. The effects of SCT on the tension of potassium induced contracture were studied in rat uterine smooth muscles. All experiments were performed in Krebs-Henseit solution which was aerated with 100% oxygen and kept at $37^{\circ}C$. Results : KCI did not produce contraction in calcium-free solution, but $CaCl_2$ induced concentration-dependent contraction after depolarizing with KCI. SCT inhibited the tonic contraction of uterine muscle as dose dependent manner. And when SCT was pretreated in calcium-free medium, it showed more powerful relaxational effect. The effect of 10mg/ml concentration of SCT was equal to that of 9nM and 70nM of nifedipine and verapamil and the relaxational effect of SCT on rat uterine muscle can be assumed to be concerned with the action of cyclic AMP. But the action mechanism of relaxation on the rat uterine muscles were concerned with the calcium channel. Conclusion : From this study we could suggest that the relaxtional effect of SCT on uterine muscle be available to preventing and curing dysmenorrhea.

• Korean Journal of Veterinary Service
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• v.18 no.2
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• pp.177-181
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• 1995

The effects of histamine were investigated on the uterine smooth muscle motility in the pig. The results were summarized as fellows : 1. Histamine caused the contraction of the porcine uterine smooth muscle and the contractile responses increased between the concetration of histamine $10^{-8}$ and $10^{-5}$ M with a dose-dependent manner. 2. The contractile response Induced by histamine ($10^{-6}$ M) was completely blocked by pretrevatment with $H_1$-histaminergic receptor blocker, pyrilamine($10^{-6}$ M) 3. The contractile response induced by histamine($10^{-6}$ M) was increased by pretreatment with $H_2$-histaminergic receptor blocker, cimetidine($10^{-6}$ M) From these results, it was concluded that the effects of uterine smooth muscle by histamine were the contraction mediated by $H_1$-histaminergic receptor and the relaxation mediated by $H_2$-histaminergic receptor in pig.

• Women's Health Nursing
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• v.23 no.2
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• pp.109-116
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• 2017

Purpose: The purpose of this study was to test effects of music therapy on stress due to preterm labor and uterine contraction in pregnant women with preterm labor. Methods: An experimental research design was used. Participants were 35 pregnant women with preterm labor who were between 20 to 37 weeks of pregnancy: control group (n=18) received only tocolytic drugs, while experimental group (n=17) received additional music therapy. In the experimental group, Traumerei was applied before Non-Stress Test (NST) from the second day to fifth day after admission as music therapy. Results: There was a statistically significant difference in stress due to preterm labor (z=-3.368, p<.001) between the two groups. Conclusion: The music therapy is an effective method for reducing the stress of pregnant women with preterm labor.

• The Korean Journal of Physiology
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• v.18 no.2
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• pp.125-137
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• 1984

The effects of external $Ca^{2+}$ ana the inhibition of Na-pump on vanadate-induced contraction in isolated human and rat uterine smooth muscle were studied and the following results were observed. 1) Vanadate induced contraction in rat uterine muscle and showed maximal contraction at concentration of $5{\times}10^{-4}$M, and the contractile response to vanadate was more sensitive in human than rat uterine muscle. 2) Vanadate-induced contraction was not completely inhibited by $Ca^{2+}$ removal from PSS and the response to $Ca^{2+}$ removal was more sensitive in human than rat uterine muscle. 3) Vanadate-induced contraction decreased with increasing concentration of verapamil, but even in the presence of $3{\times}10^{-5}M$ verapamil which inhibited 100 K-induced contraction completely. about 40% of maximal contraction remained, and its amplitude was similar to that of contraction in $Ca^{2+}$-free solution. 4) Vanadate-induced contraction was increased by the inhibition of Na-pump and this increase also could be observed in the presence of $3{\times}10^{-5}M$ verapamil. 5) After pretreatment with $Ca^{2+}$-free PSS containing ouabain Vanadate-induced contraction was not increased, but the contractile response of these tissues to the addition of external $Ca^{2+}$ was remarkably increased in the presence of vanadate. 6) $3{\times}10^{-5}$M verapamil inhibited vanadate-induced $Ca^{45}$ influx completely, but after pretreatment with ouabain vanadate could induce remarkable $Ca^{45}$ influx even in the presence of verapmil. 7) With increasing the time of pretreatment with ouabain or $K^+$-free solution, the degree of increase in contraction by vanadate was more remarkable. 8) $10^{-4}M$ papaverine stowed a considerable inhibition of the increase in the vanadate-induced contraction by pretreatment with ouabain. 9) Acetylcholine-induced contraction increased with lengthening the duration of Na-pump inhibition even in the presence of verapamil. Considering above results it seems that the uterine muscle of human is more sensitive to vanadate than that of rat, and both internal and external $Ca^{2+}$ is utilized in vanadate·induced contraction. In the case of Na-pump inhibition several smooth muscle contracting agents seems to induce $Ca^{2+}$ influx which is not inhibited by verapamil. This $Ca^{2+}$ influx seems to be inhibited by papaverine and to be associated with membrane potential, although its precise characteristics is not certain.

• CELLMED
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• v.10 no.1
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• pp.2.1-2.8
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• 2020

Uterotonics have the ability to contract uterus. Such plants might be useful in augmenting or inducing labour, expelling retained afterbirth and for abortifacient purposes. Limitations associated with conventional treatments have made herbal medicines a feasible alternative for the management of these conditions. The aim of this study was to evaluate the contractile effects of Uvariodendron kirkii extracts on isolated uterine strips of female Wistar rats. Isolated strips of Wistar rats' uteri were treated with 20, 40, 80 and 160 mg/ml concentrations of Uvariodendron kirkii aqueous extract. The plant extract was also tested against prostaglandin and oxytocin induced uterine contractions. Uvariodendron kirkii extract concentrations (20, 40, 80 and 160 mg/ml) increased the frequency of uterine contraction (16.53, 25.12, 33.48 and 56.39 percentages respectively) compared to the control. The graded extract concentrations caused a significant increase in amplitude (force) of uterine contractions by 2.87, 9.22, 16.37 and 24.32 percentages respectively. The concentrations significantly increased the frequency of oxytocin induced uterine contractions by 6.92; 28.31; 47.06, 58.78 percentages respectively. The graded extract concentrations also significantly increased the amplitude of oxytocin induced uterine contractions by 6.07; 9.40; 15.19 and 23.56 percentages respectively. Uvariodendron kirkii extract concentrations significantly increased the frequency and amplitude of prostaglandin induced contractions. The percentage increase in frequency was 11.44, 8.92, 20.65 and 35.71 at 20, 40, 80 and 160 mg/ml respectively. The mean amplitude of prostaglandin induced uterine contractions also increased (4.75, 3.89, 8.29 and 15.91% at 20. 40, 80 and 160 mg/ml respectively). The extract caused a dose dependent increase in uterine frequency and amplitude of contraction. The findings of thisstudy are useful in generating a novel uterotonic agent that will be useful in augmenting labour or in expelling retained after birth in cattle. More studies at molecular level will further elucidate the plant mechanism of action.

• Korean Journal of Veterinary Service
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• v.18 no.3
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• pp.29-35
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• 1995

The effects of prostaglandin $F_2{\alpha}$ were investigated on the uterine smooth muscle motility in the pig. The results were summarized as follows : 1. Prostaglandin $F_2{\alpha}$ caused the contraction of the porcine uterine smooth muscle and the contractile responses increased between the concentration of prostaglandine $F_2{\alpha}$ $10^{-9}$ M and $5{\times}10^{-8}$ M with a dose-dependent manner. 2. The contractile response induced by prostaglandine $F_2{\alpha}$($10^{-8}$ M) was not blocked by pre-treatment with cholinergic receptor blocker, atropine ($10^{-6}$ M). 3. The contractile response induced by prostaglandine $F_2{\alpha}$(10$^{-8}$ M) was not blocked by pretreament with ${\alpha}$-adrenergic receptor blocker, phentolamine($10^{-6}$ M) and ${\beta}$-adrenergic receptor blocker, propranolol($10^{-6}$ M). From these results, it was concluded that the effects of uterine smooth muscle by prostaglandine $F_2{\alpha}$ were only the contraction mediated by prostaglandine TEX>$F_2{\alpha}$ receptor in pig, and that it may not be related to the cholinergic and adrenergic receptor.

• The Korean Journal of Physiology
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• v.18 no.1
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• pp.37-50
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• 1984

The effects of $Ca^{++}$ and its antagonists (verapamil and $La^{+++}$) upon the spontaneous contraction and the contracture induced by 60 mM K-Tyrode solution were studied in the isolated uterine muscle. Longitudinal muscle strips were prepared from the rat uteri at estrous stage. All experiments were performed in tris-buffered Tyrode solution which was aerated with 100% $O_2$ and kept at 35^{\circ}$. The results obtained were as follows: 1) In the uterine strips contracting spontaneously, both the amplitude of peak tension and the area of contraction curve increased dose-dependently in the range of $0.5${\sim}8$ mM $Ca^{++}$. The frequency of contraction increased as the concentration of $Ca^{++}$ increased up to 2 mM, but above this concentration the frequency decreased. In $Ca^{++}-free$ media, however, contraction did not develop. In the contracture induced by 60 mM K-Tyrode solution, the developed tension increased dose-dependently as the concentration of external $Ca^{++}$ increased to 8 mM. In the absence of external $Ca^{++}$ K-contracture appeared, but it was not sustained. 2) The spontaneous contraction of rat uterus was suppressed by verapamil in proportion to an increase of its concentration and totally abolished at the concentration of $3{\times}10^{-4}\;g/l$, but the spontaneous contraction re-appeared by addition of $Ca^{++}$. The amplitude of peak tension recovered completely but the recovery of frequency was incomplete. K-contracture decreased in a dose-dependent manner after the treatment with verapamil and totally disappeared at its concentration of $3{\times}10^{-4}\;g/l$. Even in this case contracture developed again by extra $Ca^{++}$. 3) The spontaneous contractile activity was inhibited by $La^{+++}$. At the concentration of $10^{-4}$M $La^{+++}$, fibrillation appeared. In the strip inhibited by $10^{-5}M\;La^{+++}$, contractility recovered completely by extra $Ca^{++}$ while in the $10^{-4}M\;La^{+++}$ treated preparation, the rhythmic spontaneous contraction did not develop even at the concentration of 16 mM $Ca^{++}$. After the initial transient depression of contracture tension by $10^{-3}M$ of $La^{+++}$, the strip stowed considerably large size of contracture, hardly influenced by external $Ca^{++}$ or verapamil. The results obtained in this experiment suggest that in the rat uterine muscle there would be some competitive actions between $Ca^{++}$ and its antagonists. It is speculated that $Ca^{++}$ plays an important role in the conduction of excitation, and $La^{+++}$ influences upon cellular $Ca^{++}$ mobilization and re-uptake process as well as transmembrane $Ca^{++}$ transport in a K-depolarized state.