Immune function in cows | Imunska funkcija pri kravah
2009
Woodward, J., Univ. of British Columbia, Vancouver (Canada) | Murdoch, G.K. | Thompson, J.R. | Kaiserlink Von, M. | Field, C.J. | Christopherson, R.J.
There were transient decreases in all categories of lymphocytes (B cells, naive T cells, activated T cells, helper T cells, cytotoxic T cells and gamma-delta T cells) as well as the respiratory activity of neutrophils in blood from cows at and shortly after calving. Lymphocyte numbers recovered by day 7, and neutrophil activity recovered by day 7 to 14 post-calving. Glutamine increased percentages of circulating naive T cells and B cells following calving compared to control cows. Lymphocytes from control animals had significantly higher basal (unstimulated) thymidine uptakes than lymphocytes from glutamine supplemented cows. Results indicate that glutamine treatment may have reduced systemic exposure to bacteria or toxins, reducing activation of immune cells. Ten g/day of rumen protected methionine increased the relative percentages of the CD62L, CD25, and CD8 positive lymphocyte subgroups compared to the control or 20g/day methionine group. Na 239;ve T and B cells carry the CD62L (L-selectin) marker, which is a homing molecule that enables cells to move into tissues such as the lymph node. Once activated, lymphocytes (CD25+) no longer express the CD62L marker, facilitating activated cells to traffic to the affected tissue site. Further studies are needed to clarify the lymphocyte subtype dynamics in response to methionine.
显示更多 [+] 显示较少 [-]