Linked Life Data

7888511

Source:http://linkedlifedata.com/resource/pubmed/id/7888511

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
6
pubmed:dateCreated
1995-4-20
pubmed:abstractText
Reproductive activity in the Djungarian hamster is controlled by seasonal variations in day length. Exposure to long days stimulates testis development, while exposure to short days induces testis regression. We recently found that testis regression after gonadotropin deprivation in rats is associated with increases in apoptosis. Here we sought to determine whether or not apoptosis is associated with the testis regression and/or recrudescence that occurs naturally in seasonally breeding mammals. Newborn male hamsters were maintained on long days (16L:8D) until 3 wk of age before being transferred to short days (8L:16D). Following decreases in serum FSH within 3 days of exposure to short days, testis weight decreased by 52% at Day 10, reaching a 70% decrease after 21 days. Analysis of testis cell DNA fragmentation showed a 4.9-fold increase of low-molecular-weight DNA as early as 5 days after transfer to short days; this was followed by a time-dependent decrease. The observed increases in testis cell apoptosis were correlated with decreases in serum testosterone, but decreases in Leydig cell LH receptor content were delayed. In a second study, 6-wk-old hamsters with regressed testes due to a 3-wk exposure to short days were transferred back to long days. After increases in serum FSH within 3 days of photostimulation, a 2-fold elevation in testis weight was found at Day 5. The increase in testis weight was associated with a 65% decrease of testis apoptosis within 5 days of photostimulation. Also, increases in serum testosterone and LH receptor content were observed after 5 and 10 days of exposure to long days, respectively.(ABSTRACT TRUNCATED AT 250 WORDS)
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Dec
pubmed:issn
0006-3363
pubmed:author
pubmed:issnType
Print
pubmed:volume
51
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
1315-21
pubmed:dateRevised
2007-11-14
pubmed:meshHeading
pubmed:year
1994
pubmed:articleTitle
Photoperiod regulates testis cell apoptosis in Djungarian hamsters.
pubmed:affiliation
Department of Gynecology/Obstetrics, Stanford University Medical School, California 94305-5317.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S.