This study was conducted to determine the effects of
shipping stress on the immune system in domestic lambs (Ovis
aries) and to determine the potential of the thymic peptide,
thymulin, to reduce those effects of stress on the immune
system. Treatments consisted of no shipping (as unstressed
controls), shipping (as stressed controls) or shipping plus
two doses of thymulin. The shipping procedure was conducted
for two consecutive days. The responses were measured in
three ways. First, the ability of peripheral blood
mononuclear cells (PBMN) to respond to four different doses
of the mitogen, Interleukin-2 (IL-2), was measured. Second,
antibody response to a standard antigen dose over a three
week period following the stress was examined. Third, the
plasma cortisol concentrations in stressed versus unstressed
and in thymulin treated lambs were compared.
There were no differences between any of the four
treatment groups (p>0.44) with respect to the animals'
lymphocyte proliferative ability. Although there were no
detectable differences, caution should be used in
interpreting these results, because of technical
difficulties encountered with a key reagent in the assay.
Antibody titers were measured at weekly intervals for
each of three consecutive weeks following the stressing
procedure. These results also showed no treatment effect
between any of the four groups (p>0.39).
A comparison of cortisol levels in the four groups
revealed that shipping stress increased plasma cortisol
concentrations, and thymulin treatment at either dose and on
both days of shipment inhibited (p<0.0001 and p<0.047,
for day one and two, respectively) that stress-induced
increase in cortisol. Interestingly, these results indicate
that treatment with thymulin was effective in negating the
stress-associated increase in plasma cortisol levels in the
lambs. These in vivo data support a possible
immunomodulatory function of thymulin. / Graduation date: 1997
| Identifer | oai:union.ndltd.org:ORGSU/oai:ir.library.oregonstate.edu:1957/34275 |
| Date | 04 March 1997 |
| Creators | Christian, Richard L., (Richard Leroy), 1971- |
| Contributors | Davis, Steven L. |
| Source Sets | Oregon State University |
| Language | en_US |
| Detected Language | English |
| Type | Thesis/Dissertation |
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