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Published on: December 1, 2015
Involution of the sheep mammary gland
L Tatarczuch1, C Philip, C S Lee
1School of Veterinary Science, University of Melbourne, Parkville, Victoria, Australia.
Journal of Anatomy
|April 1, 1997
Summary
Ovine mammary gland involution occurs through apoptosis, a programmed cell death process. This mechanism removes duct and alveolar epithelial cells while preserving the gland's structure.
Area of Science:
- Reproductive Biology
- Cell Biology
- Histology
Background:
- Mammary gland involution is a complex process involving significant tissue remodeling after lactation.
- Understanding the cellular mechanisms of involution is crucial for reproductive biology and veterinary medicine.
Purpose of the Study:
- To investigate the cellular and ultrastructural changes in the ovine mammary gland during the early stages of involution.
- To identify the specific cell types involved in mammary gland regression and the mechanisms driving this process.
Main Methods:
- Light and electron microscopy were employed to examine mammary gland tissue.
- Immunohistochemistry was used to identify specific cell populations, including macrophages (CD45+, MHC class II+).
Main Results:
- Apoptosis was identified in duct and alveolar epithelial cells, peaking at 4 days post-weaning.
- Macrophages phagocytosed apoptotic epithelial cells, and occasional apoptotic bodies were found in lumina.
- Myoepithelial cells underwent shrinkage but not apoptosis; blood capillary regression also occurred via apoptosis.
- Complete involution was observed by 30 days post-weaning.
Conclusions:
- Mammary gland involution in ewes is primarily mediated by apoptosis.
- Apoptosis facilitates controlled cell deletion, maintaining the epithelial architecture and integrity during involution.
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