Richard at work in the lab
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Richard at work in the lab |
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Richard
Blalock
Department of Biology Mentor: Terry Derting Title of Presentation: The effects of testosterone
on the immune system in white-footed mice (Peromyscus leucopus).
Presented at: Kentucky Academy of Science Annual
Meeting. First Place Award for Oral presentation in Zoology and Biochemistry.
Dick also presented his research at the MSU Undergraduate Research Symposium
in 2003, at which he won the The research was supported by: Howard Hughes
Medical Institute
ABSTRACT Testosterone is believed to be immunosuppressive
in mammals. Recent research suggests, however, that testosterone may cause
redistribution of leukocytes rather an actual reduction in leukocyte numbers.
One hormone known to induce immunoredistribution is corticosterone. To
investigate the effects of testosterone on immunity, we tested the null
hypotheses that: 1) testosterone has no effect on the distribution of
leukocytes and 2) testosterone has no effect on corticosterone level.
We established four groups of adult male white-footed mice (Peromsycus
leucopus): 1) control, 2) testosterone-treated, 3) immunochallenged, and
4) testosterone-treated and immunochallenged. Testosterone injections
were given to mice for 10 days. The immunochallenged mice were treated
with sheep red blood cells (SRBC) and phytohemagglutinin (PHA). To determine
if immunoredistribution occurred blood samples were taken from the heart
and the retro-orbital sinus. There was no significant redistribution of
leukocytes in any group of mice; however, the reaction to PHA was much
greater in the control mice than the testosterone treated mice. Total
white blood cell counts revealed no significant differences between the
control group and testosterone treated group. Corticosterone levels were
lowered by the testosterone injections so redistribution could not have
occurred due to corticosterone. We concluded that testosterone does not
raise corticosterone levels and is not related to immunoredistribution.
Testosterone did however, suppress the humoral immune response. Date Modified July, 2003
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