Effect of relaxin on facilitation of parturition in dairy heifers

Bagna, B.; Schwabe, Christian; Anderson, L. L.

doi:10.1530/jrf.0.0910605

Cited by 28 publications

(11 citation statements)

References 12 publications

(12 reference statements)

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“…Relaxin is essential for the live delivery of pups in the rat 14,15 and of pigs in the sow 16,17 . Furthermore, relaxin treatment has been reported to improve calving in beef 18,19 and dairy heifers 20 by advancing the dilatation of the cervix and increasing pelvic area, thereby decreasing the incidence of dystocia. Also, there is evidence that the aborting dog exhibits depressed serum relaxin prior to pregnancy loss 21,22 .…”

Section: Introductionmentioning

confidence: 99%

Evaluation of Systemic Relaxin Blood Profiles in Horses as a Means of Assessing Placental Function in High‐Risk Pregnancies and Responsiveness to Therapeutic Strategies

Ryan

Christiansen

Hopper

et al. 2009

Annals of the New York Academy of Sciences

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Placental insufficiency is regarded as the primary factor contributing to late-term abortion and perinatal death of foals. Often when problems associated with late-term pregnancy in the horse are manifest the condition is well-advanced and therapeutic intervention may not be effective in rescuing the pregnancy. If a compromised pregnancy due to placental insufficiency could be identified early, the pregnancy might be sustained through medical intervention. Because the placenta is the sole source of circulating relaxin in the mare, we hypothesized that systemic relaxin may serve as a biomarker of placental function and fetal well-being and a predictor of pregnancy outcome at delivery. To test this hypothesis we monitored plasma relaxin in mares (light breeds) with normal and problematic pregnancies from clinical cases presented to the veterinary hospital and in pregnant mares experimentally inoculated with Streptococcus equi zooepidemicus to induce uterine infection. Upon establishment of placentitis, mares were assigned to different therapeutic strategies and responsiveness was monitored. Blood was collected during the third trimester of pregnancy, and relaxin content was determined using a homologous equine relaxin radioimmunoassay. The results reported here show a positive relationship between low circulating relaxin and poor pregnancy outcome in mares with compromised placental function. While relaxin may have value as a diagnostic assay for identifying mares with high-risk pregnancies associated with placental dysfunction, the variable results obtained from mares undergoing drug treatment for experimentally induced placentitis make it difficult to determine the reliability of relaxin for evaluating therapeutic efficacy.

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Section: Introductionmentioning

confidence: 99%

Evaluation of Systemic Relaxin Blood Profiles in Horses as a Means of Assessing Placental Function in High‐Risk Pregnancies and Responsiveness to Therapeutic Strategies

Ryan

Christiansen

Hopper

et al. 2009

Annals of the New York Academy of Sciences

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“…Substitution of glycine by cysteine at position 5 75 in the human progesterone receptor abrogates binding of RU 486, but not that of an agonist (Benhamou et al, 1992). Relaxin administered to cattle late in pregnancy decreases circulating progesterone and also advances parturition (Musah et al, 1986;Bagna et al, 1991) and it decreases progesterone in cyclic ewes (Akinbami et al, 1990).…”

Section: Introductionmentioning

confidence: 99%

Attenuation of antepartum relaxin surge and induction of parturition by antiprogesterone RU 486 in sheep

Gazal

Li²,

Schwabe³

et al. 1993

Reproduction

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Pregnant ewes were injected with either the antiprogesterone, RU 486 (4 mg kg-1 body weight, i.m.; n = 5), 3000 iu relaxin (i.m.; n = 9), or diluent (n = 8) at 12:00 h on days 144 and 145, to determine its effect on progesterone and relaxin secretion, and on induction of lambing. RU 486 induced earlier lambing (P < 0.01) compared with diluent treatment, but relaxin treatment did not significantly reduce the interval to parturition. Mean injection-lambing intervals were 31 +/- 2, 109 +/- 23 and 121 +/- 27 h for the RU 486, relaxin and diluent groups, respectively. There was no incidence of difficult birth (dystocia); all lambs were vigorous at birth; and placenta delivery was rapid (within 207 min) with RU 486 and relaxin treatments compared with diluent treated controls. Plasma progesterone concentrations averaged 11 ng ml-1 during the pretreatment period for all animals. RU 486 had a biphasic effect on progesterone concentrations, causing an initial increase (P < 0.05) within 2 h, and then an abrupt drop (P < 0.01) to 6 ng ml-1 by 18:00 h on day 145. Progesterone concentrations remained consistently lower (P < 0.05) in relaxin-treated ewes than in diluent-treated controls from days 144 to 147 and then began a steady decrease to 4 ng ml-1 on the day of parturition (days 149 and 150) in both groups.(ABSTRACT TRUNCATED AT 250 WORDS)

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“…While the accuracy of porcine RLX (100 ng/ml) was confirmed, since it decreased the contractions of myometrial strips from swine ( Figure 2E). The lack of effect of porcine RLX on bovine myometrium has been surprised, since it had used to study effect on E2, OT and P4 secretion [34,41] and to cause a cervical dilatation [34,42] in beef heifers in vivo, as well as cow RLX preparations gave reactions of identity with the porcine RLX [43]. Therefore, it is suggest that RLX from swine and human is not appropriate to use as a support of in vitro model to study the effect of xenobiotics on myometrial contractions.…”

Section: Results With Discussionmentioning

confidence: 99%

The Preliminary Study About the Involvement of Relaxine in Adverse Effect of Polychlorinated Biphenyls on Bovine Myometrial Contractions

Wróbel¹

2017

J Clin Mol Endocrinol

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Polychlorinated biphenyls (PCBs) are a group of synthetic xenobiotics, which were used in lots of industrial applications. Two individual congers (PCB 153 and PCB 77) belong to the most prominent environmental contaminations among PCBs, but they have opposite type of configuration and therefore they can exert a different way of action. Since PCBs increased the force of myometrial contractions, in this work, their effect on myometrial sensitivity on inhibitor of myometrial contractions (relaxine, RLX) was studied.Bovine myometrial cells and strips, and luteal cell at 4-8 month of pregnancy, were obtained accidentally in commercial abattoir. They were treated by PCB 153 and PCB 77 and mRNA expression of RLX receptor in myometrial cells and contractions of myometrial strips as well as the secretion of progesterone (P4) and oxytocin (OT) from luteal cells, were measured under their effect.Both studied congeners decreased (P<0.05) the mRNA expression of RLX receptor in myometrium. Admittedly, both PCB 77 and 153 increased (P<0.05) the basal force of contractions, while RLX showed any effect on myometrial contractions. Studied PCBs increased also (P<0.05) secretion of P4 and OT from luteal cells.It is suggested that PCBs can decreased the sensitivity of myometrium on RLX but their direct effect on RLX function have to be further investigated. Keywords: Endocrine Disruption; Pregnancy; Uterus IntroductionPolychlorinated biphenyls (PCBs) are a group of synthetic, chlorinated aryl hydrocarbons, which were extensively used in lots of industrial applications, mainly in transformers, capacitors or as hydraulic fluids, heat exchange liquids as well as plasticizers and others [1]. Because of different degree of chlorination, there are possible up to 209 congeners of PCBs. Among them, 3,3 ' ,4,4 ' -tetrachlorobiphenyl (PCB 77) is one of the most abundant PCB congeners in human milk. This congener is a non-ortho chlorine substituted with coplanar configuration and appear to exert its toxic effects via interacting with the cytosolic aryl hydrocarbon receptor (Ahr). Hence is recognized also as dioxin-like PCBs [2]. Since PCB 77 can affect the cell also through estrogen [3] and glucocorticoid receptors [4], it is recognized as a significant environmental pollutant and endocrine disruptor [3] with a wide spectrum of way of action. Admittedly 2,2',4,4', 5,5'-hexachlorobiphenyl PCB 153 is also one of the most prominent environmental contaminants, but oppositely to PCB 77 is classified as di-ortho, non-coplanar, non-dioxin congener of PCBs [5] and is known to have rather estrogenic properties [6]. Even though PCBs production and use were banned in USA and Europe more than three decades ago, they are still measured in environment [7]. Due to their lipophilic nature and resistance for biodegradation, PCBs have been bio-accumulated in animal tissues [8], also in domestic animals [9,10]. Therefore PCBs have been also measured in food samples [11] and they can be mentioned as a serious health risk.Since PCBs accumulation in preg...

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Effect of relaxin on facilitation of parturition in dairy heifers

Cited by 28 publications

References 12 publications

Evaluation of Systemic Relaxin Blood Profiles in Horses as a Means of Assessing Placental Function in High‐Risk Pregnancies and Responsiveness to Therapeutic Strategies

Evaluation of Systemic Relaxin Blood Profiles in Horses as a Means of Assessing Placental Function in High‐Risk Pregnancies and Responsiveness to Therapeutic Strategies

Attenuation of antepartum relaxin surge and induction of parturition by antiprogesterone RU 486 in sheep

The Preliminary Study About the Involvement of Relaxine in Adverse Effect of Polychlorinated Biphenyls on Bovine Myometrial Contractions

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