Effects of intramammary infusions of interleukin-8 on milk protein composition and induction of acute-phase protein in cows during mammary involution.
The effects of interleukin-8 (IL-8) on bovine mammary functions such as milk protein secretion and the blood-milk barrier during mammary involution were evaluated. Following the final milking, recombinant bovine (rb) IL-8 (5 or 25 microg) and a saline placebo were individually infused into the left- and right-front teat cisterns of 6 cows, respectively. Three cows without treatment at the final milking were also used as controls. Mammary secretions and blood were collected at -24, 0, 10, 24, 72, 168, 336, and 720 h after infusion. In the mammary glands infused with 25 microg of rbIL-8, the increases in somatic cell counts and in the concentrations of serum albumin, IgG1 and IgG2, and the decreases in the concentrations of alpha- and beta-casein and beta-lactoglobulin were greater than in the control glands. In the mammary glands infused with 5 microg of rbIL-8, compared to the glands infused with 25 microg of rbIL-8, these changes were moderate. These results indicate that rbIL-8 impairs the integrity of the blood-milk barrier and suppresses milk-specific protein secretions. In the cows infused with 25 microg of rbIL-8, the rectal temperature and serum haptoglobin level were transiently elevated after the infusion, showing that intramammary infusion of rbIL-8 could elicit systemic inflammation.
Watanabe
Atsushi
A
Hokkaido Research Station, National Institute of Animal Health, Sapporo 062-0045, Japan. awata@affrc.go.jp
Yagi
Yukio
Y
Shiono
Hiroki
H
Yokomizo
Yuichi
Y
Inumaru
Shigeki
S
D000209:Acute-Phase Proteins / Q000187:drug effects*; D000818:Animals; D002417:Cattle / Q000378:metabolism* / Q000502:physiology; D002452:Cell Count / Q000662:veterinary; D005260:Female; D006242:Haptoglobins / Q000737:chemistry / Q000187:drug effects; D007263:Infusions, Parenteral / Q000662:veterinary; D016209:Interleukin-8 / Q000276:immunology / Q000494:pharmacology*; D007774:Lactation / Q000187:drug effects / Q000378:metabolism; D008321:Mammary Glands, Animal / Q000187:drug effects* / Q000378:metabolism; D008414:Mastitis, Bovine / Q000378:metabolism; D008892:Milk / Q000737:chemistry / Q000166:cytology / Q000378:metabolism; D008894:Milk Proteins / Q000737:chemistry / Q000187:drug effects*; D011897:Random Allocation; D011994:Recombinant Proteins / Q000494:pharmacology; D013997:Time Factors
D000209:Acute-Phase Proteins; D006242:Haptoglobins; D016209:Interleukin-8; D008894:Milk Proteins; D011994:Recombinant Proteins