Leukocyte and cytokine accumulation in the ovine teat and udder during endotoxin-induced inflammation.

摘要

The accumulation of leukocytes, ovine serum albumin and the cytokines interleukin-1beta (IL-1beta), tumour necrosis factor-alpha (TNF-alpha), interleukin-8 (IL-8), granulocyte-macrophage colony-stimulating factor (GM-CSF) and interferon-gamma (IFN-gamma) was studied during endotoxin-induced inflammation in lactating and dry ovine udders, and in the teat cisterns of dry ewes after surgical closure of the passage between the teat and udder cisterns. Three samples from each dose group were taken before infusion and hourly up to 10 h after infusion of 0.1, 1 or 10 鎔 of endotoxin (Escherichia coli serotype O55:B5), or infusion of pyrogen-free saline as a control. Rectal temperatures were also measured. A significant dose- and time-dependent accumulation of leukocytes, mainly neutrophils, was observed in the lactating udders and in the teat cisterns. In the dry udders, the leukocyte accumulation was significant for time- but not for dose-dependence. Peak numbers of cells were reached in 3-4 h after infusion in the dry udders and in the teat cisterns, but not until 10 h after infusion in the lactating udders. The changes in the ovine serum albumin concentrations mostly paralleled changes in leukocyte numbers. A role was indicated for TNF-alpha, IL-8 and GM-CSF, but not for IL-1beta and IFN-gamma, during endotoxin-induced inflammation in the ovine udder. Release of TNF-alpha, IL-8 and GM-CSF was most prominent in lactating udders, peaking at 2 or 3 h after infusion, but was also detected in dry uddersand teat cisterns. Detectable levels of IL-1beta and IFN-gamma were occasionally found in all 3 groups.