Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
4
pubmed:dateCreated
1985-8-12
pubmed:abstractText
Testicular volumes and serum testosterone concentrations were determined biweekly in 5 adult and 4 yearling woodchucks maintained indoors from December through August. Food and water were provided ad libitum except for 2 mo beginning at the winter solstice when feeding and lighting (12L:12D) supplemental to available natural light were discontinued. Temperatures fluctuated with outdoor temperatures greater than 4 degrees C. No significant hibernation occurred. Testes in adults were small in December (0.3-1.8 cm3), largest in February and March (3.5-5.6 cm3), and smallest in late June (0.1-0.5 cm3). Testosterone was basal in December (less than 0.6 ng/ml), maximal (3.4-6.6 ng/ml) between early January and late March, and minimal from April through August (less than 0.8 ng/ml). In yearlings, maximum testes volumes (1.6 cm3) and serum testosterone (0.9 +/- 0.2 ng/ml) were less, and occurred later, than in adults. Testosterone levels and testis volumes measured in newly captured woodchucks in March and April and again 2-3 mo later were generally similar to those of their laboratory counterparts. Thus, in woodchucks: annual cycles of testosterone production and of testes recrudescence and regression parallel each other with maxima during the short, late-winter breeding season; those cycles are not altered significantly by the absence of hibernation or the present conditions of captivity; and yearling males apparently are not an important part of the breeding population.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
May
pubmed:issn
0006-3363
pubmed:author
pubmed:issnType
Print
pubmed:volume
32
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
804-12
pubmed:dateRevised
2007-11-14
pubmed:meshHeading
pubmed:year
1985
pubmed:articleTitle
Circannual changes in serum testosterone concentrations of adult and yearling woodchucks (Marmota monax).
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S.