f) Blueridge Poster Presentation
1
RESEARCH POSTER PRESENTATION DESIGN © 2012 www.PosterPresentations.com Fescue toxicosis is an ongoing challenge within the USA where in 2011 over 35 million acres were made up of endophyte- infected tall fescue grass and more than 700,000 horses consumed it as their primary forage. The endophyte, a type of fungus, has a symbiotic relationship with a host plant. The fescue grass provides shelter and protection while the endophyte helps the host plant collect a greater amount of nutrients. The host plant and the endophyte can produce toxins such as ergovaline which has been linked to cause symptoms of fescue toxicosis such as agalactia which is characterized by a lack of udder development and milk production in pregnant mares. Ergovaline is a D₂-dopamine receptor agonist which inhibits estrogens from binding to their proper receptors causing the body to produce a greater amount of estrogen. Normally 30-40 days before parturition (birth) progestogen levels should increase and 5-10 days before parturition prolactin levels should increase. Estrogen levels should decrease before prolactin levels increase. In cases of fescue toxicosis, progestogen and prolactin levels are much lower than needed for proper development while estrogen levels are too high. In Japan there has been an ongoing issue with mares developing agalactia. Considering that the common cause for agalactia in the USA is fescue toxicosis, agalactic mares in Japan have been tested to see if fescue toxicosis or something like it may be the cause. If the agalactia is caused by fescue toxicosis, then domperidone treatment may be used to relieve some of the symptoms. Abstract Objectives The Endocrine Disruptive Effects of Ergopeptine Alkaloids on Pregnant Mares Evans, Tim J. © 2011 Mares are treated with bromocriptine •Bromocriptine, a semi-synthetic alkaloid, acts similarly to ergovaline by blocking D₂-dopamine receptors Mares treated with domperidone therapy •Domperidone is a D₂-dopamine receptor antagonist which allows the estrogen to attach to its proper receptors Mares treated with reserpine •Depletes brain levels of dopamine, serotonine, and/or norepinephrine Procedures Bromocriptine Treatment Causes Decrease in PRL & PRG Concentrations Results Conclusion Bromocriptine is used to mimic the effects of ergovaline. The presence of bromocriptine caused a decrease in PRL & PRG concentrations. Domperidone therapy is effective in treatment of fescue toxicosis in typical cases. However, only a low concentration of PRL is recognized within the agalactic mare from Japan. This indicates that something other than ergovaline must be causing agalactia in this particular mare. Since the pathology in which agalactia is caused within the mare is different from the pathology seen within fescue toxicosis, it is less likely that domperidone therapy will be as effective. Currently the cause of agalactia in the case from Japan is unknown. References Evans, T. J. (2011). The Endocrine Disruptive Effects of Ergopeptine Alkaloids on Pregnant Mares. Veterinary Clinics of North America: Equine Practice, 165-173. Herron, C. (2015). Domperidone Therapy in the Fight Against Fescue Toxicosis. Senior Honors Thesis. Korosue, K., et al. (2013). Changes in Serum Concentrations of Prolactin, Progestagens, and Estradiol-17ß and Biochemical Parameters During Peripartum in an Agalactic Mare. Journal of Equine Veterinary Science, 279-286. Neotyphodium coenophialum. (2012, December 21). Retrieved March 23, 2015, from Microbe Wiki: https://microbewiki.kenyon.edu/index.php/Neotyphodium_coenophi alum Nevala, R. (2001). Isoflavones. Effects of genistein and daidzein on arterial tone and blood pressure in rats. Acknowledgements The author thanks Dr. Laura Ong and Dr. Kelly Vaughan for their involvement editing this presentation. The author also thanks the Biology Department at King University for funding this project. This presentation is an extension of Chelsea Herron’s Senior Honors Thesis (2015). •Determine the general pathology of fescue toxicosis •Discover what is effective for treatment of fescue toxicosis •Determine if the agalactic mares in Japan are suffering from fescue toxicosis Presented by: Chelsea Herron Fescue Toxicosis: Disruption of Pregnant Mare Endocrine Systems by Ergopeptine Alkaloids Figure 4 Weekly changes in serum concentrations of progestagens from a period of 10 weeks before parturition to a week after parturition in the agalactic mare, compared with those of the control mares (Korosue, Kenji et al., 2013). Figure 3 Daily changes in serum prolactin concentrations from 10 days before parturition to the day after parturition in the agalactic mare, compared with those of the control mares (Korosue, Kenji et al., 2013). Figure A shows the underdeveloped udder of an agalactic mare. Figure B shows the normal udder development expected for a pregnant mare 2- 6 weeks before parturition (Korosue, Kenji et al., 2013). Figure C Ergot alkaloid ergovaline from endophyte Neotyphodium coenophialum associated with the effects of fescue toxicosis. A D₂- dopamine receptor agonist (Neotyphodium coenophialum, 2012). Figure D Estradiol-17ß: a hormone that should decrease before the pronounced increase of prolactin 5-10 days before parturition (Nevala, Riikka, 2001). Changes in Serum Concentrations of Prolactin, Progestagens, and Estradiol-17ß and Biochemical Parameters During Peripartum in an Agalactic Mare Korosue, Kenji et al. © 2013 Hormone levels are determined for the normal mares Hormone levels are determined for the agalactic mare •Blood taken and analyzed •Primary hormones: PRL, PRG, 17ß- estradiol Figure 1a prolactin (PRL) concentrations after bromocriptine treatment. Figure 1b progestagen (PRG) concentrations after bromocriptine treatment. Both PRL & PRG are significantly low compared to the control group depicted by asterisk lines (Evans, Tim J., 2011). Figure 2a PRL concentrations after domperidone therapy depicted by asterisk line. PRL concentrations after reserpine therapy depicted by triangles. Figure 2b PRG concentrations after therapy depicted by asterisk line. PRG concentrations after reserpine therapy depicted by triangles (Evans, Tim J., 2011). In both studies prolactin concentrations were considerably lower than normal. The first study showed a significant decrease in progesterone, but the second study had relatively normal levels of progesterone. Agalactia vs. Normal Development Progestagens (ng/ml) Fig. 1a Fig. 1b Fig. 2a Fig. 2b Domperidone Therapy Causes Increase in PRL & PRG Concentrations Low Concentration of PRL in Agalactic Mare Relatively Normal Concentration of PRG in Agalactic Mare Diagram of Ergovaline Diagram of Estradiol-17ß
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Transcript of f) Blueridge Poster Presentation
RESEARCH POSTER PRESENTATION DESIGN © 2012
www.PosterPresentations.com
Fescue toxicosis is an ongoing challenge within the USA where in 2011 over 35 million acres were made up of endophyte-infected tall fescue grass and more than 700,000 horses consumed it as their primary forage. The endophyte, a type of fungus, has a symbiotic relationship with a host plant. The fescue grass provides shelter and protection while the endophyte helps the host plant collect a greater amount of nutrients. The host plant and the endophyte can produce toxins such as ergovaline which has been linked to cause symptoms of fescue toxicosis such as agalactia which is characterized by a lack of udder development and milk production in pregnant mares. Ergovaline is a D₂-dopamine receptor agonist which inhibits estrogens from binding to their proper receptors causing the body to produce a greater amount of estrogen. Normally 30-40 days before parturition (birth) progestogen levels should increase and 5-10 days before parturition prolactin levels should increase. Estrogen levels should decrease before prolactin levels increase. In cases of fescue toxicosis, progestogen and prolactin levels are much lower than needed for proper development while estrogen levels are too high. In Japan there has been an ongoing issue with mares developing agalactia. Considering that the common cause for agalactia in the USA is fescue toxicosis, agalactic mares in Japan have been tested to see if fescue toxicosis or something like it may be the cause. If the agalactia is caused by fescue toxicosis, then domperidone treatment may be used to relieve some of the symptoms.
Abstract
Objectives
The Endocrine Disruptive Effects of Ergopeptine Alkaloids on
Pregnant MaresEvans, Tim J. © 2011
Mares are treated with bromocriptine•Bromocriptine, a semi-synthetic alkaloid, acts
similarly to ergovaline by blocking D₂-dopamine receptors
Mares treated with domperidone therapy•Domperidone is a D₂-dopamine receptor antagonist
which allows the estrogen to attach to its proper receptors
Mares treated with reserpine •Depletes brain levels of dopamine, serotonine,
and/or norepinephrine
Procedures
Bromocriptine Treatment Causes Decrease in PRL & PRG Concentrations
Results
ConclusionBromocriptine is used to mimic the effects of
ergovaline. The presence of bromocriptine caused a decrease in PRL & PRG concentrations. Domperidone therapy is effective in treatment of fescue toxicosis in typical cases.
However, only a low concentration of PRL is recognized within the agalactic mare from Japan. This indicates that something other than ergovaline must be causing agalactia in this particular mare. Since the pathology in which agalactia is caused within the mare is different from the pathology seen within fescue toxicosis, it is less likely that domperidone therapy will be as effective. Currently the cause of agalactia in the case from Japan is unknown.
ReferencesEvans, T. J. (2011). The Endocrine Disruptive Effects of Ergopeptine Alkaloids on
Pregnant Mares. Veterinary Clinics of North America: Equine Practice, 165-173.
Herron, C. (2015). Domperidone Therapy in the Fight Against Fescue Toxicosis. Senior Honors Thesis.
Korosue, K., et al. (2013). Changes in Serum Concentrations of Prolactin, Progestagens, and Estradiol-17ß and Biochemical Parameters During Peripartum in an Agalactic Mare. Journal of Equine Veterinary Science, 279-286.
Neotyphodium coenophialum. (2012, December 21). Retrieved March 23, 2015, from Microbe Wiki: https://microbewiki.kenyon.edu/index.php/Neotyphodium_coenophialum
Nevala, R. (2001). Isoflavones. Effects of genistein and daidzein on arterial tone and blood pressure in rats.
AcknowledgementsThe author thanks Dr. Laura Ong and Dr. Kelly Vaughan for their
involvement editing this presentation. The author also thanks the Biology Department at King University for funding this project. This presentation is an extension of Chelsea Herron’s Senior Honors Thesis (2015).
•Determine the general pathology of fescue toxicosis•Discover what is effective for treatment of
fescue toxicosis•Determine if the agalactic mares in Japan are
suffering from fescue toxicosis
Presented by: Chelsea Herron
Fescue Toxicosis:
Disruption of Pregnant Mare Endocrine Systems by Ergopeptine Alkaloids
Figure 4 Weekly changes in serum concentrations of progestagens from a period of 10 weeks before parturition to a week after parturition in the agalactic mare, compared with those of the control mares (Korosue, Kenji et al., 2013).
Figure 3 Daily changes in serum prolactin concentrations from 10 days before parturition to the day after parturition in the agalactic mare, compared with those of the control mares (Korosue, Kenji et al., 2013).
Figure A shows the underdeveloped udder of an agalactic mare. Figure B shows the normal udder development expected for a pregnant mare 2-6 weeks before parturition (Korosue, Kenji et al., 2013).
Figure C Ergot alkaloid ergovaline from endophyte Neotyphodium coenophialum associated with the effects of fescue toxicosis. A D₂-dopamine receptor agonist (Neotyphodium coenophialum, 2012).
Figure D Estradiol-17ß: a hormone that should decrease before the pronounced increase of prolactin 5-10 days before parturition (Nevala, Riikka, 2001).
Changes in Serum Concentrations of Prolactin, Progestagens,
and Estradiol-17ß and Biochemical Parameters During Peripartum in an Agalactic Mare
Korosue, Kenji et al. © 2013
Hormone levels are determined for the normal maresHormone levels are determined for the agalactic mare
•Blood taken and analyzed•Primary hormones: PRL, PRG, 17ß-estradiol
Figure 1a prolactin (PRL) concentrations after bromocriptine treatment. Figure 1b progestagen (PRG) concentrations after bromocriptine treatment. Both PRL & PRG are significantly low compared to the control group depicted by asterisk lines (Evans, Tim J., 2011).
Figure 2a PRL concentrations after domperidone therapy depicted by asterisk line. PRL concentrations after reserpine therapy depicted by triangles. Figure 2b PRG concentrations after therapy depicted by asterisk line. PRG concentrations after reserpine therapy depicted by triangles (Evans, Tim J., 2011).
In both studies prolactin concentrations were considerably lower than normal. The first study showed a significant decrease in progesterone, but the second study had relatively normal levels of progesterone.
Agalactia vs. Normal Development
Prog
esta
gens
(ng/
ml)
Fig. 1a Fig. 1b
Fig. 2a Fig. 2b
Domperidone Therapy Causes Increase in PRL & PRG Concentrations
Low Concentration of PRL in Agalactic Mare
Relatively Normal Concentration of PRG in Agalactic Mare
Diagram of Ergovaline
Diagram of Estradiol-17ß
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