Apoptosis and oxidative stress of infiltrated neutrophils obtained from mammary glands of goats during various stages of lactation.
OBJECTIVE
To examine apoptosis in infiltrated neutrophils during involution of mammary glands and compare them with those obtained during late and peak lactation, and to measure oxidative stress and activities of antioxidant enzymes and determine involvement of free radicals in apoptosis of infiltrated neutrophils.


METHODS
Neutrophils from mammary gland secretions of 8 goats at 4 stages (late and peak lactation and 1 and 2 weeks after end of lactation).


METHODS
DNA fragmentation was evaluated to characterize apoptosis. Concentration of thiobarbituric acid reactive substances (TBARS) was used to evaluate oxidative stress. Activities of superoxide dismutase and glutathione peroxidase were determined.


RESULTS
Neutrophils from secretions obtained after end of lactation of all goats and from late-lactation milk of some goats underwent prominent apoptosis, whereas neutrophils from peak lactation secretions did not. Higher lipid peroxidation and lower antioxidant enzyme activities in neutrophils during involution were observed, compared with those during late and peak lactation. A significant negative correlation existed between TBARS concentrations and antioxidant enzyme activities during the nonlactating period.


CONCLUSIONS
Apoptosis is a feature of infiltrated neutrophils during involution of mammary glands in goats. This feature may allow prompt resorption and clearance of infiltrated neutrophils without damaging surrounding tissues. Increased oxidative stress in infiltrated neutrophils from secretions obtained after end of lactation is probably related to a deficiency in antioxidant enzyme activities. Understanding the relationship between apoptosis and oxidative stress will lead to new strategies for manipulating involution and reducing tissue damage.
Su
Wen Jeng
WJ
Department of Animal Science, National Chung Hsing University, Taichung, Taiwan.
Chang
Chai Ju
CJ
Peh
Huo Cheng
HC
Lee
Shuang Lin
SL
Huang
Mu Chiou
MC
Zhao
Xin
X
D000818:Animals; D017209:Apoptosis; D053938:DNA Fragmentation; D004587:Electrophoresis, Agar Gel; D005260:Female; D005979:Glutathione Peroxidase / Q000378:metabolism; D006041:Goats / Q000502:physiology*; D007774:Lactation / Q000502:physiology*; D015227:Lipid Peroxidation; D008321:Mammary Glands, Animal / Q000166:cytology*; D009504:Neutrophils / Q000166:cytology*; D018384:Oxidative Stress; D013482:Superoxide Dismutase / Q000378:metabolism; D017392:Thiobarbituric Acid Reactive Substances / Q000032:analysis
D017392:Thiobarbituric Acid Reactive Substances; D005979:Glutathione Peroxidase; D013482:Superoxide Dismutase