Role of Prostaglandin Production in Spontaneous and Oxytocin-Induced Uterine Contractile Activity in in Vitro Pregnant Rat Uteri*

Endocrinology ◽  
1979 ◽  
Vol 105 (1) ◽  
pp. 47-51 ◽  
Author(s):  
N. H. DUBIN ◽  
R. B. GHODGAONKAR ◽  
T. M. KING
Keyword(s):  
Contractile Activity ◽  
Pregnant Rat ◽  
Prostaglandin Production ◽  
Uterine Contractile

Uterine contractile activity and fetal outcome in rats treated with vitamin C during late gestational variable stress exposure

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Shakiru A. Salami ◽  
Hussein M. Salahdeen ◽  
Abidemi E. Obafemi ◽  
Babatunde A. Murtala
Keyword(s):  
Vitamin C ◽  
Stress Responses ◽  
Contractile Activity ◽  
Exposed Group ◽  
Magnesium Ions ◽  
Uterine Contractility ◽  
Contractile Responses ◽  
Uterine Contractile ◽  
Vitamin C Supplementation

Abstract Objectives Stress responses vary throughout pregnancy and impact of late gestational variable stress (LGVS) with vitamin C supplementation on uterine contractility is barely explored. This study investigates fetal weight outcome and in-vitro uterine contractile responses to pharmacological agents during LGVS exposure. Methods Twenty four nulliparous pregnant rats were divided into four groups of six. During gestation days 10–19, groups 1 & 2 received normal saline and vitamin C (10 mg/kg) respectively. Groups 3 and 4 were exposed to stress (sleep deprivation, predator exposure, immobility, rapid cage changes, noise, and foreign object) with group 4 concurrently supplemented with vitamin C (10 mg/kg). Serum cortisol, oxidative bio-markers, fetal weights and in-vitro contractile responses of excised uterine tissue to acetylcholine (Ach), oxytocin, calcium chloride (CaCl2), potassium chloride (KCl), diclofenac, and magnesium ions were determined. Results Malondialdehyde activity and cortisol were significantly increased in variable stress only exposed group when compared with control and vitamin C supplemented groups. Fetal body weights, superoxide dismutase and catalase activity were significantly reduced in variable stress only exposed group. Significantly impaired contractile responses to Ach, CaCl2 & KCl in variable stress only exposed group were modulated in vitamin C supplemented groups. Impaired contractile response to oxytocin was however not reversed. Relaxation responses to diclofenac and magnesium ions were statistically unaltered across groups. Conclusions Impaired fetal weights and uterine contractile activity to Ach, CaCl2 and KCl during LGVS was modulated by vitamin C supplementation. Impaired oxytocin contractile activity was however unreversed.

Optoelectronic transducer for in vivo recording of oviductal contractile activity

1980 ◽  
Vol 239 (3) ◽  
pp. R326-R331
Author(s):  
S. A. Halbert ◽  
R. J. Bourdage ◽  
J. L. Boling ◽  
J. A. Ringo ◽  
R. J. Blandau
Keyword(s):  
Contractile Activity ◽  
Red Light ◽  
Muscular Activity ◽  
Optical Signal ◽  
In Vivo Experiments ◽  
Optoelectronic Transducer ◽  
Optical Analog

An optoelectronic instrument to record oviductal muscular activity in chronically instrumented animals was evaluated in in vitro and in vivo experiments. The intensity of red light transmitted through the oviduct was modulated by contractions of the oviductal wall producing an optical analog of the mechanical events. Accuracy of the analog was tested by Fourier analysis of signals from mechanical and optoelectronic transducers placed at the same site on the oviduct; the results validated the use of the optical device as a contraction event sensor. Contractions of the tubal mesenteries had less effect on the optical signal than on signals from extraluminal mechanical transducers. Optical and photographic recordings of luminal transport in exposed oviducts showed a correspondence of intraluminal movements to events in the optical contraction signal. This instrument does not alter tubal function, and thus it is an especially useful experimental tool to investigate the role of oviductal muscular activity in fertility.

Accumulation of Adenosine 3′,5′-Monophosphate and Relaxation in the Rat Uterus In Vitro

1971 ◽  
Vol 49 (11) ◽  
pp. 999-1004 ◽  
Author(s):  
Ivo Polacek ◽  
Jean Bolan ◽  
Edwin E. Daniel
Keyword(s):  
Cyclic Amp ◽  
Contractile Activity ◽  
Phosphodiesterase Activity ◽  
Dibutyryl Camp ◽  
Rat Uterus ◽  
Low Concentrations ◽  
Uterine Contractile ◽  
Camp Levels

Theophylline, diazoxide, and papaverine in low concentrations relaxed the uterus with minimal or no elevation of cyclic AMP (cAMP) levels. In higher concentrations, theophylline relaxed the uterus and increased its cAMP levels, but imidazole reversed the increase in cAMP without causing recontraction. Imidazole and NaF caused uterine contractures but did not detectably decrease cAMP levels until several minutes after the onset of contractures. The uterine relaxations produced by theophylline and/or dibutyryl cAMP in amounts which increased uterine cAMP were not reversed by propranolol. These results eliminate the possibility that propranolol interfered with a relaxant action of cAMP. Along with previous data, these results also show that uterine contractile activity was not determined primarily by the general levels of cAMP and that phosphodiesterase activity in the uterus was insufficient to rapidly affect these cAMP levels. Also, substances like theophylline, diazoxide, and papaverine, postulated to inhibit phosphodiesterase activity, did not bring about their relaxant effects by this mechanism.

Interruption of parturition in rats by morphine: a result of inhibition of oxytocin secretion

1989 ◽  
Vol 121 (3) ◽  
pp. 521-536 ◽  
Author(s):  
J. A. Russell ◽  
R. G. Gosden ◽  
E. M. Humphreys ◽  
R. Cutting ◽  
N. Fitzsimons ◽  
...  
Keyword(s):  
Contractile Activity ◽  
Post Partum ◽  
Maternal Behaviour ◽  
Opiate Antagonist ◽  
Opioid Receptor Agonist ◽  
Μ Opioid Receptor ◽  
Pup Mortality ◽  
Mean Time

ABSTRACT Oxytocin secretion is inhibited by opioids, and oxytocin is important in parturition. The effects on parturition of morphine, a relatively selective μ-opioid receptor agonist, were studied in the rat. Morphine or vehicle with or without the opiate antagonist naloxone were administered immediately after the birth of the second pup and the subsequent course of parturition was recorded in a total of 80 rats. Both s.c. morphine (10 mg/kg) and intracerebroventricular (i.c.v.) morphine (18 μg through a previously implanted cannula) interrupted parturition, delaying the birth of the sixth pup after treatment to 187·3 ± 35·9 (s.e.m.) min and 195·4 ± 19·5 min respectively, compared with 46·4 ± 3·7 and 66·1 ± 17·5 min after vehicle alone. The dose of morphine given i.c.v. had no effect when given s.c. Naloxone given concurrently prevented the effects of morphine. Eventually the rate of parturition in the morphine-treated groups recovered. Perinatal pup mortality rate was not increased when morphine was given to the mothers, but it did inhibit the expression of normal intrapartum maternal behaviour. Pup mortality was increased 48 h post partum by morphine given during parturition, and it reduced the proportion of rats with normal maternal behaviour 24 h post partum. Morphine did not affect spontaneous or oxytocin-stimulated contractile activity of the parturient uterus in vitro. The concentration of oxytocin in trunk blood plasma was decreased 40 min after i.c.v. morphine (24·3 ± 3·9 vs 39·3± 6·5 pmol/l in controls), as was vasopressin (7·2 ± 1·5 vs 19·7 ± 4·5 pmol/l in controls). Intravenous infusion of oxytocin (2–5 mU/min for 144·3 ± 8·2 min; total infused 448·5 ± 61·9 mU) after i.c.v. morphine re-started parturition; all pups were born to these rats (mean time to pup 6, 110·3 ± 12·7 min) before the i.v. vehicle-infused rats given i.c.v. morphine re-started (mean time to pup 6, 406·3±125·2 min). It is concluded that morphine given during parturition acts centrally through opioid receptors to inhibit oxytocin secretion, and impairs the expression of maternal behaviour. Reversal of the effects of morphine on parturition by i.v. oxytocin demonstrates the important role of oxytocin in fetus ejection and expulsion. Journal of Endocrinology (1989) 121, 521–536

scholarly journals Экспериментальные модели сократительной активности миометрия

2020 ◽  
Author(s):  
A.A. Yakovleva ◽  
N.G. Pavlova
Keyword(s):  
In Silico ◽  
Contractile Activity ◽  
Experimental Models ◽  
Pacemaker Activity ◽  
Single View ◽  
Uterine Contractile ◽  
Experimental Approaches

Сократительная деятельность матки до настоящего времени остается актуальным вопросом фундаментальных исследований, поскольку отсутствуют единые представления о биомеханике маточного сокращения, необходимые для профилактики родового и акушерского травматизма. Цель работы - оценка ограничений и возможностей экспериментальных моделей, предназначенных для изучения сократительной активности миометрия. Методика. Основными экспериментальными подходами к изучению сократительной активности матки являлись исследования in vitro, in situ, in vivo, in silico, а также их сочетание. Результаты. В статье рассмотрены исследования, в которых использованы различные сочетания экспериментальных подходов, обсуждаются результаты, полученные при моделировании в экспериментах, обсуждаются результаты изучения синхронизации сокращения отделов матки на различных моделях, а также результаты исследования пейсмейкерной активности миометрия и возможность экстраполяции полученных данных на человека. В связи с активным развитием компьютерных технологий в статье поднимается вопрос об их использовании в моделировании сократительной активности матки человека. Заключение. Делается заключение, что комплексный подход, включающий электромиографические, биохимические и морфологические исследования в хроническом эксперименте, является наиболее адекватным для изучения сократительной активности миометрия и функционального состояния нормально развитых и отставших в развитии плодов, что позволит разработать комплексные методы профилактики родового и акушерского травматизма.Uterine contractile activity remains an important issue of fundamental research as there is no single view of the biomechanics of uterine contraction necessary for the prevention of parturition and obstetric trauma until now. The aim of the review was to assess advantages and limitations of experimental models described in the literature for study uterine contractile activity. At the present time main experimental approaches for study myometrium contractile activity are research in vitro, in situ, in vivo, in silico and the their combinations. The literature presents experimental approaches, different models of uterine contractions synchronization and study of myometrium pacemaker activity. Due to active development of computer technologies there is a need to model human uterine contractile activity with a simplified anatomy. The authors propose that combination of electromyographic, biochemical and morphological methods in chronic experiment is the most correct and appropriate direction for the assessment of the myometrium contractile activity and functional state of normally developed and growth restricted fetuses.

scholarly journals Role of biologically active molecules in uterine contractile activity

2019 ◽  
Vol 68 (1) ◽  
pp. 21-27
Author(s):  
Tatyana U. Kuzminykh ◽  
Vera Yu. Borisova ◽  
Igor P. Nikolayenkov ◽  
Georgy R. Kozonov ◽  
Gulrukhsor Kh. Tolibova
Keyword(s):  
Nitric Oxide ◽  
Nitric Oxide Synthase ◽  
Adhesion Molecules ◽  
Connexin 43 ◽  
Contractile Activity ◽  
Active Phase ◽  
Uterine Contractile ◽  
Uterine Inertia ◽  
Oxide Synthase

Hypothesis/aims of study. Myometrial relaxation and contraction require synchronous cellular interactions. At present, it has been established that the coordination of myometrial contractile activity is carried out by a conduction system constructed from gap junctions with intercellular channels. There are no clinical data on inhibiting (nitric oxide synthase) and activating (connexin-43) factors of uterine contractile activity in the myometrium during pregnancy and parturition in the published literature. This study was undertaken to measure the expression levels of nitric oxide synthase, adhesion molecules CD51, CD61, and connexin-43 in the myometrium during pregnancy and parturition; and to assess the role of inhibitory and activating factors in the development of uterine contractile activity. Study design, materials and methods. An immunohistochemical study of myometrial biopsy specimens obtained from the lower uterus segment during cesarean section was performed in eight women with a full-term physiological pregnancy, in another eight individuals in the active phase of uncomplicated parturition, and in eight patients with uterine inertia. Integrins (CD51 and CD61 proteins) were used as markers of cell adhesion. Localization and the number of intercellular contacts were assessed by measuring the expression level of connexin-43, with the intensity of oxidative processes assessed by nitric oxide synthase activity. Results. In the myometrium, in the active phase of physiological parturition, a three-fold increase in the expression of activating (CD51, CD61, and connexin-43) factors of uterine contractile activity and a five-fold decrease in that of inhibitory (nitric oxide synthase) ones occur compared to those in full-term physiological pregnancy. Conclusion. In the pathogenesis of uterine inertia and resistance to labor induction, an important role is played by the decreased expression of adhesion molecules (CD51, CD61) and connexin-43 and the increased expression of nitric oxide synthase in the myometrium.

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