Evaluation of systemic relaxin blood profiles in horses as a means of assessing placental function in high-risk pregnancies and responsiveness to therapeutic strategies

Peter L. Ryan, David L. Christiansen, Richard M. Hopper, Carol Bagnell, Wendy E. Vaala, Michelle M. Leblanc

Research output: Chapter in Book/Report/Conference proceedingConference contribution

11 Citations (Scopus)

Abstract

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.

Original languageEnglish (US)
Title of host publicationRelaxin and Related Peptides Fifth International Conference
PublisherBlackwell Publishing Inc.
Pages169-178
Number of pages10
ISBN (Print)9781573317214
DOIs
StatePublished - Jan 1 2009

Publication series

NameAnnals of the New York Academy of Sciences
Volume1160
ISSN (Print)0077-8923
ISSN (Electronic)1749-6632

Fingerprint

Relaxin
High-Risk Pregnancy
Horses
Blood
Pregnancy
Streptococcus equi
Placental Insufficiency
Therapeutics
Pregnancy Outcome
Animal Hospitals
Drug therapy
Horse
Evaluation
Responsiveness
Third Pregnancy Trimester
Biomarkers
Placenta
Radioimmunoassay
Assays
Plasmas

All Science Journal Classification (ASJC) codes

  • Neuroscience(all)
  • Biochemistry, Genetics and Molecular Biology(all)
  • History and Philosophy of Science

Keywords

  • Equine
  • Problematic pregnancies
  • Relaxin

Cite this

Ryan, P. L., Christiansen, D. L., Hopper, R. M., Bagnell, C., Vaala, W. E., & Leblanc, M. M. (2009). Evaluation of systemic relaxin blood profiles in horses as a means of assessing placental function in high-risk pregnancies and responsiveness to therapeutic strategies. In Relaxin and Related Peptides Fifth International Conference (pp. 169-178). (Annals of the New York Academy of Sciences; Vol. 1160). Blackwell Publishing Inc.. https://doi.org/10.1111/j.1749-6632.2008.03802.x
Ryan, Peter L. ; Christiansen, David L. ; Hopper, Richard M. ; Bagnell, Carol ; Vaala, Wendy E. ; Leblanc, Michelle M. / Evaluation of systemic relaxin blood profiles in horses as a means of assessing placental function in high-risk pregnancies and responsiveness to therapeutic strategies. Relaxin and Related Peptides Fifth International Conference. Blackwell Publishing Inc., 2009. pp. 169-178 (Annals of the New York Academy of Sciences).
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abstract = "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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Ryan, PL, Christiansen, DL, Hopper, RM, Bagnell, C, Vaala, WE & Leblanc, MM 2009, Evaluation of systemic relaxin blood profiles in horses as a means of assessing placental function in high-risk pregnancies and responsiveness to therapeutic strategies. in Relaxin and Related Peptides Fifth International Conference. Annals of the New York Academy of Sciences, vol. 1160, Blackwell Publishing Inc., pp. 169-178. https://doi.org/10.1111/j.1749-6632.2008.03802.x

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, Peter L.; Christiansen, David L.; Hopper, Richard M.; Bagnell, Carol; Vaala, Wendy E.; Leblanc, Michelle M.

Relaxin and Related Peptides Fifth International Conference. Blackwell Publishing Inc., 2009. p. 169-178 (Annals of the New York Academy of Sciences; Vol. 1160).

Research output: Chapter in Book/Report/Conference proceedingConference contribution

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AU - Christiansen, David L.

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AB - 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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Ryan PL, Christiansen DL, Hopper RM, Bagnell C, Vaala WE, Leblanc MM. Evaluation of systemic relaxin blood profiles in horses as a means of assessing placental function in high-risk pregnancies and responsiveness to therapeutic strategies. In Relaxin and Related Peptides Fifth International Conference. Blackwell Publishing Inc. 2009. p. 169-178. (Annals of the New York Academy of Sciences). https://doi.org/10.1111/j.1749-6632.2008.03802.x