Effects of vitamin E on urokinase-plasminogen activator receptor expression by bovine neutrophils.
OBJECTIVE
To determine the effect of vitamin E supplementation on urokinase-plasminogen activator (u-PA) receptor (u-PAR) expression by neutrophils of dairy cows.


METHODS
16 healthy Holstein dairy cows.


METHODS
16 cows were assigned to 1 of 2 experimental groups: control (no vitamin E supplementation) and vitamin E supplementation. Supplementation of vitamin E started 4 weeks prior to and continued up to 4 weeks after parturition and included oral administration of vitamin E at 3,000 U/cow per day; these cows also received 1 injection of vitamin E (5,000 units), 1 week prior to the expected date of parturition. Blood samples were collected, and neutrophils were isolated weekly throughout the experimental period. The following variables were measured: u-PA (mRNA), total cell-associated u-PA activity, membrane-bound u-PA activity, and free unoccupied u-PA binding sites on the cell membrane of neutrophils.


RESULTS
Stimulated neutrophils isolated from cows that received vitamin E supplementation had significantly higher u-PA mRNA and total cell-associated and membrane-bound u-PA activity at postpartum week 1, compared with those of stimulated neutrophils isolated from control cows. There were no differences between groups throughout the whole experimental period in u-PA binding sites of neutrophils.


CONCLUSIONS
The increased total cell-associated and membrane-bound u-PA activity in neutrophils isolated from cows that received vitamin E may facilitate the ability of neutrophils to extravasate and reach the mammary gland at postpartum week 1. Rapid recruitment of neutrophils is critical for proper defense of the gland.
Politis
I
I
Department of Animal Production, Agricultural University of Athens, Greece.
Hidiroglou
N
N
Cheli
F
F
Baldi
A
A
D000818:Animals; D001665:Binding Sites; D015152:Blotting, Northern; D002417:Cattle / Q000097:blood* / Q000276:immunology; D019587:Dietary Supplements; D005260:Female; D009504:Neutrophils / Q000276:immunology / Q000378:metabolism*; D011247:Pregnancy; D012333:RNA, Messenger / Q000096:biosynthesis / Q000235:genetics; D011956:Receptors, Cell Surface / Q000096:biosynthesis* / Q000097:blood / Q000276:immunology; D055293:Receptors, Urokinase Plasminogen Activator; D014810:Vitamin E / Q000008:administration & dosage / Q000097:blood / Q000494:pharmacology*
D012333:RNA, Messenger; D011956:Receptors, Cell Surface; D055293:Receptors, Urokinase Plasminogen Activator; D014810:Vitamin E