Switch to
Predicate | Object |
---|---|
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-meshheading:4005348-Animals,
pubmed-meshheading:4005348-Biological Clocks,
pubmed-meshheading:4005348-Female,
pubmed-meshheading:4005348-Male,
pubmed-meshheading:4005348-Marmota,
pubmed-meshheading:4005348-Reproduction,
pubmed-meshheading:4005348-Sciuridae,
pubmed-meshheading:4005348-Seasons,
pubmed-meshheading:4005348-Testis,
pubmed-meshheading:4005348-Testosterone
|
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.
|