| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
|
|
|
|||||||
|
|||||||||
1 Dairy and Swine Research and Development Centre, Agriculture and Agri-Food Canada, Lennoxville, QC, Canada, J1M 1Z3
2 Department of Animal Science, McGill University, 21111 Lakeshore Road, Ste. Anne de Bellevue, QC, Canada, H9X 3V9
3 Food Research and Development Centre, Agriculture and Agri-Food Canada, St-Hyacinthe, QC, Canada
Corresponding author: Pierre Lacasse; e-mail: lacassep{at}agr.gc.ca.
During and after diapedesis, milk polymorphonu-clear neutrophils (PMN) release many proteases that have the potential of degrading extracellular matrix proteins and milk proteins. However, the kinetics of milk proteolysis during inflammation and the underlying mechanisms are poorly defined. The enzymes involved in bovine mammary tissue destruction were investigated in this study using an endotoxin-induced mastitis model. Using zymography techniques, the proteolytic activity of milk and mammary tissue during mastitis was examined. Mastitic milk produced 6 caseolysis bands, 4 of which differed from the ones produced by plasmin. Peak proteolytic activity, bovine serum albumin contents, and mammary tissue damage occurred between 6 and 12 h postchallenge. Mastitic milk proteases hydrolyzed casein, gelatin, collagen, hemoglobin, mammary gland membrane proteins, and lactoferrin. These results confirm that mastitic milk proteases have a broad spectrum of activity. The hydrolytic activity of mastitic milk was partially inhibited by aprotinin, EDTA, 1,10-phenanthroline, leupeptin, and pefabloc. When cocultured with normal mammary tissue, mastitic milk, but not normal milk, caused mammary tissue degradation. In situ zymography of mammary gland showed increased proteolytic activity in mastitic tissue compared with normal tissue. The similarity of zymograms of mastitic milk, blood PMN, milk somatic cells, and PMN strongly suggests that proteases in mastitic milk mainly originate from milk PMN. These results suggest that proteases released by PMN are actively involved in udder tissue damage during mastitis.
Key Words: endotoxin mastitis • mammary gland • matrix metalloproteinase • protease
Abbreviation key: MMP = matrix metalloproteinase, OD = optical density, PCH = postchallenge hour, PMN = polymorphonuclear neutrophils, ROS = reactive oxygen species, SC = somatic cells.
This article has been cited by other articles:
|
|
 |
|
  G. Tremblay, P. Bernier-Dodier, L. Delbecchi, G. F. Wagner, B. G. Talbot, and P. Lacasse Local control of mammary involution: Is stanniocalcin-1 involved? J Dairy Sci, May 1, 2009; 92(5): 1998 - 2006. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 K. J. Harvatine, J. W. Perfield II, and D. E. Bauman Expression of Enzymes and Key Regulators of Lipid Synthesis Is Upregulated in Adipose Tissue during CLA-Induced Milk Fat Depression in Dairy Cows J. Nutr., May 1, 2009; 139(5): 849 - 854. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 X. Zhao and P. Lacasse Mammary tissue damage during bovine mastitis: Causes and control J Anim Sci, March 1, 2008; 86(13_suppl): 57 - 65. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
A. K. G. Kadegowda, L. S. Piperova, and R. A. Erdman Principal Component and Multivariate Analysis of Milk Long-Chain Fatty Acid Composition During Diet-Induced Milk Fat Depression J Dairy Sci, February 1, 2008; 91(2): 749 - 759. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
D. E. Bauman, J. W. Perfield II, K. J. Harvatine, and L. H. Baumgard Regulation of Fat Synthesis by Conjugated Linoleic Acid: Lactation and the Ruminant Model J. Nutr., February 1, 2008; 138(2): 403 - 409. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
L. T. Cao, J. Q. Wu, F. Xie, S. H. Hu, and Y. Mo Efficacy of Nisin in Treatment of Clinical Mastitis in Lactating Dairy Cows J Dairy Sci, August 1, 2007; 90(8): 3980 - 3985. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
W. P. Weiss and J. S. Hogan Effects of Dietary Vitamin C on Neutrophil Function and Responses to Intramammary Infusion of Lipopolysaccharide in Periparturient Dairy Cows J Dairy Sci, February 1, 2007; 90(2): 731 - 739. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
A. L. Lock, C. Tyburczy, D. A. Dwyer, K. J. Harvatine, F. Destaillats, Z. Mouloungui, L. Candy, and D. E. Bauman Trans-10 Octadecenoic Acid Does Not Reduce Milk Fat Synthesis in Dairy Cows J. Nutr., January 1, 2007; 137(1): 71 - 76. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
K. Lauzon, X. Zhao, and P. Lacasse Deferoxamine reduces tissue damage during endotoxin-induced mastitis in dairy cows. J Dairy Sci, October 1, 2006; 89(10): 3846 - 3857. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
M. H. Weng, C. J. Chang, W. Y. Chen, W. K. Chou, H. C. Peh, M. C. Huang, M. T. Chen, and H. Nagahata Contribution of somatic cell-associated activation of plasminogen to caseinolysis within the goat mammary gland. J Dairy Sci, June 1, 2006; 89(6): 2025 - 2037. [Abstract] [Full Text] [PDF]
|
|
| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
