Cell death during natural and induced luteal regression in mares.
Abstract: In mares, little information is available on the type of cell death that occurs during natural and induced luteal regression. Corpora lutea were collected from mares in the early luteal phase, days 3-4 (n = 4); mid-luteal phase, day 10 (n = 5); early regression, day 14 (n = 4); late regression, day 17 (n = 4); and 12 and 36 h (n = 3 per group) after PGF2alpha administration on day 10. Histological and ultrastructural sections were examined and TUNEL was used to detect DNA fragmentation. In early luteal regression, there were more pyknotic luteal cells and extracellular round dense bodies compared with the mid-luteal phase. By late regression, there was a significant decline (P < 0.01) in the number of round dense body clusters and a marked accumulation of lipid. Twelve and 36 h after PGF2alpha administration, changes were similar to those seen in natural regression, but there was also a marked infiltration of neutrophils. Accumulation of lipid was not apparent until 36 h after PGF2alpha administration. Ultrastructural examination revealed rarefaction and distortion of the mitochondrial cristae in most of the luteal cells by the mid-luteal phase. Luteal cells showed shrinkage, accumulation of lipid with foamy appearance, and disruption in both smooth endoplasmic reticulum and mitochondria during natural and induced regression. Some luteal cells showed fragmented or pyknotic chromatin characteristic of apoptosis. Other luteal cells showed crenation of the nuclear membrane and shrinkage of the nucleus, features not characteristic of apoptotic cell death. In late regression, capillaries were obstructed by swollen endothelial cells and round dense bodies. These results show that structural regression may be initiated as early as the mid-luteal phase, and is clearly visible by day 14 in natural regression and 12 h after induced regression. Apoptosis did appear to be involved in luteolysis in the equine corpus luteum, but non-apoptotic changes were also observed in some luteal cells during regression. Accumulation of lipid was a late feature of luteal regression.
Publication Date: 2002-03-01 PubMed ID: 11869188
The Equine Research Bank provides access to a large database of publicly available scientific literature. Inclusion in the Research Bank does not imply endorsement of study methods or findings by Mad Barn.
- Journal Article
- Research Support
- Non-U.S. Gov't
Summary
This research summary has been generated with artificial intelligence and may contain errors and omissions. Refer to the original study to confirm details provided. Submit correction.
This research article focuses on the type of cell death observed during the natural and induced regression of the corpus luteum in mares. The study observed structural changes, including apoptosis and non-apoptotic alterations, during different stages of luteal regression, and identified lipid accumulation as a later characteristic of the process.
Study Design
- The researchers obtained corpora lutea from mares during different stages of the luteal phase – early luteal phase, mid-luteal phase, early regression, late regression, and at two time points (12 and 36 hours) after administration of PGF2alpha on day 10.
- The study employed histological and ultrastructural examination techniques along with TUNEL, a method used to detect DNA fragmentation, to study cell death during luteal regression.
Results and Observations
- In the initial stages of luteal regression, the researchers found an increased number of pyknotic (shrinking and condensing) luteal cells and extracellular round dense bodies compared to the mid-luteal phase.
- In the late regression phase, the team noticed a significant decrease in the quantity of round dense body clusters, indicating the progression of luteal regression. Notably, there was a visible accumulation of lipid at this stage.
- Changes seen 12 and 36 hours post PGF2alpha administration mirrored those observed in natural regression, including an increased infiltration of neutrophils. Lipid accumulation was not observed until 36 hours after PGF2alpha administration.
- Ultrastructural examination revealed other changes such as rarefaction and distortion of the mitochondrial cristae in most of the luteal cells by the mid-luteal phase along with shrinkage of luteal cells, smooth endoplasmic reticulum and mitochondria, and appearance of accumulated lipid with a foamy appearance during both natural and induced regression.
Conclusion
- The study concluded that the structural regression of the corpus luteum could start as early as the mid-luteal phase and becomes prominently visible by day 14 in natural regression and 12 hours after induced regression.
- While apoptosis was identified as a factor in luteolysis in the equine corpus luteum, the authors also found evidence of non-apoptotic changes in some luteal cells during regression.
- Lipid accumulation was identified as a significant later characteristic of luteal regression.
Cite This Article
APA
Al-Zi'abi MO, Fraser HM, Watson ED.
(2002).
Cell death during natural and induced luteal regression in mares.
Reproduction, 123(1), 67-77.
Publication
Researcher Affiliations
- Department of Veterinary Clinical Studies, University of Edinburgh, Easter Bush, Midlothian EH25 9RG, UK.
MeSH Terms
- Analysis of Variance
- Animals
- Apoptosis / drug effects
- Corpus Luteum / drug effects
- Corpus Luteum / ultrastructure
- Dinoprostone / pharmacology
- Female
- Horses / physiology
- In Situ Nick-End Labeling
- Inclusion Bodies / ultrastructure
- Lipids / analysis
- Luteolysis / physiology
- Microscopy, Electron
- Mitochondria / ultrastructure
- Neutrophils / cytology
- Progesterone / blood
Citations
This article has been cited 6 times.- Kozai K, Hojo T, Tokuyama S, Szóstek AZ, Takahashi M, Sakatani M, Nambo Y, Skarzynski DJ, Okuda K. Expression of aldo-keto reductase 1C23 in the equine corpus luteum in different luteal phases.. J Reprod Dev 2014 Apr 24;60(2):150-4.
- Galvão AM, Ferreira-Dias G, Skarzynski DJ. Cytokines and angiogenesis in the corpus luteum.. Mediators Inflamm 2013;2013:420186.
- Beigi Boroujeni M, Beigi Boroujeni N, Salehnia M, Marandi E, Beigi Boroujeni M. Ultrastructural changes of corpus luteum after ovarian stimulation at implantation period.. Iran Biomed J 2012;16(1):33-7.
- Shirasuna K, Jiemtaweeboon S, Raddatz S, Nitta A, Schuberth HJ, Bollwein H, Shimizu T, Miyamoto A. Rapid accumulation of polymorphonuclear neutrophils in the Corpus luteum during prostaglandin F(2α)-induced luteolysis in the cow.. PLoS One 2012;7(1):e29054.
- Jiemtaweeboon S, Shirasuna K, Nitta A, Kobayashi A, Schuberth HJ, Shimizu T, Miyamoto A. Evidence that polymorphonuclear neutrophils infiltrate into the developing corpus luteum and promote angiogenesis with interleukin-8 in the cow.. Reprod Biol Endocrinol 2011 Jun 8;9:79.
- Davis JS, Rueda BR, Spanel-Borowski K. Microvascular endothelial cells of the corpus luteum.. Reprod Biol Endocrinol 2003 Nov 10;1:89.
Use Nutrition Calculator
Check if your horse's diet meets their nutrition requirements with our easy-to-use tool Check your horse's diet with our easy-to-use tool
Talk to a Nutritionist
Discuss your horse's feeding plan with our experts over a free phone consultation Discuss your horse's diet over a phone consultation
Submit Diet Evaluation
Get a customized feeding plan for your horse formulated by our equine nutritionists Get a custom feeding plan formulated by our nutritionists
