Linked Life Data

15777807

Source:http://linkedlifedata.com/resource/pubmed/id/15777807

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
4
pubmed:dateCreated
2005-3-21
pubmed:abstractText
Individuals that display elaborate sexually selected characters often show reduced immune function. According to the immunocompetence handicap hypothesis, testosterone (T) is responsible for this result as it drives the development and maintenance of sexual characters and causes immunosuppression. But glucocorticoids also have strong influences on immune function and may also be elevated in reproductively active males. Here, we compared immune activity using the phytohemagglutinin (PHA) skin test in three discrete groups of male marine iguanas (Amblyrhynchus cristatus): territorials, satellites, and bachelors. Males of these three reproductive phenotypes had indistinguishable T concentrations during the height of the breeding season, but their corticosterone (cort) concentrations, body condition and hematocrit were significantly different. Territorial males, the animals with the most elaborate sexual ornaments and behaviors, had lower immune responses and body condition but higher cort concentrations and hematocrit than satellites or bachelors. To test directly cort's immunosuppressive role, we elevated cort by either restraining animals or additionally injecting cort and compared their PHA swelling response with the response of free-roaming animals. Such experimental elevation of cort significantly decreased immune activity in both restrained and cort-injected animals. Our data show that cort can induce immunosuppression, but they do not support the immunocompetence handicap hypothesis in its narrow sense because T concentrations were not related to immunosuppression.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Apr
pubmed:issn
0018-506X
pubmed:author
pubmed:issnType
Print
pubmed:volume
47
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
419-29
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed:year
2005
pubmed:articleTitle
Corticosterone suppresses immune activity in territorial Galápagos marine iguanas during reproduction.
pubmed:affiliation
Department of Experimental Ecology, University of Ulm, Albert-Einstein-Allee 11, 89069 Ulm, Germany. silke.berger@biologie.uni-ulm.de
pubmed:publicationType
Journal Article, Comparative Study, Research Support, U.S. Gov't, Non-P.H.S., Research Support, Non-U.S. Gov't