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Androgen control of immunocompetence in the male house finch, Carpodacus mexicanus Müller (2005)
| Venue: | Journal of Experimental Biology |
| Citations: | 15 - 1 self |
BibTeX
@ARTICLE{Deviche05androgencontrol,
author = {Pierre Deviche and Luis Cortez},
title = {Androgen control of immunocompetence in the male house finch, Carpodacus mexicanus Müller},
journal = {Journal of Experimental Biology},
year = {2005},
pages = {1287--1295}
}
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Abstract
The immunocompetence handicap (ICH) hypothesis predicts that elevated levels of the gonadal androgen testosterone (T) entail obligatory costs, such as immunosuppression, but evidence supporting this immunosuppressive influence is equivocal. To investigate this question, adult males house finches, Carpodacus mexicanus, were exposed to short days and chronically treated with T-filled (T males; N=10) or empty (C males; N=10) Silastic capsules. Testosterone administration increased plasma T levels and the size of the cloacal protuberance, an androgen-dependent secondary sexual characteristic. To study humoral immunity, finches received injections of sheep red blood cells (SRBC) and we measured circulating concentrations of antibodies to these cells with a hemagglutination test. All males produced antibodies following four SRBC injections at weekly Summary intervals. Antibody titers in T and C males did not differ 5·days after the fourth injection, but were 59 % lower in T than C males 2·weeks later. To study cell-mediated immunity, we measured the local inflammatory response to an injection of phytohemaglutinin (PHA). This response in T and C males was similar 1·day after PHA injection, but was 58 % less in T than C males 2·days following the injection. Thus, T and C males mounted similar humoral and cell-mediated immune responses, but T treatment compromised maintenance of these responses. The results, demonstrating immunosuppressive effects of elevated T, are consistent with the ICH hypothesis. Key words: androgen, cell-mediated immunity, humoral immunity, immunocompetence handicap hypothesis, inflammation.
Keyphrases
androgen control male house finch carpodacus mexicanus ller cell-mediated immunity humoral immunity hemagglutination test sheep red blood cell pha injection weekly summary interval gonadal androgen testosterone ich hypothesis local inflammatory response androgen-dependent secondary sexual characteristic cell-mediated immune response immunocompetence handicap hypothesis obligatory cost carpodacus mexicanus immunosuppressive influence immunosuppressive effect immunocompetence handicap fourth injection srbc injection elevated level antibody titer adult male house finch key word cloacal protuberance short day plasma level silastic capsule
