Linked Life Data

6780913

Source:http://linkedlifedata.com/resource/pubmed/id/6780913

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
5796
pubmed:dateCreated
1981-4-21
pubmed:abstractText
Animals inhabiting areas where there are drastic changes in the environment often reproduce only during limited time periods to ensure that young are raised in optimal environmental conditions. The lack of a well defined breeding season in many domesticated animals, presumably because the selective pressures for seasonal breeding have been minimized, suggests that the neuroendocrine events controlling seasonal cyclicity have been bred out of these animals. Little is known about the underlying neuroendocrine changes which may occur during the evolution of a species from a seasonal to a nonseasonal breeder. Whereas the changing photoperiod is the primary environmental cue which initiates and/or terminates the reproductive season in many animals, this is not so in the albino rat Rattus norvegicus, a model nonseasonal breeder. Nevertheless, daylength can influence various reproductive parameters in laboratory rats, suggesting that some of the neuroendocrine components that controlled seasonal breeding previously are still extant in this species. To test this hypothesis, we investigated the effect of daylength on the responsiveness of the neuroendocrine--gonadal axis to the negative-feedback effects of testosterone. This paradigm was chosen because of the important role played by photic-induced changes in steroid feedback sensitivity in the control of seasonal reproduction. We report here that although daylength has very little effect on neuroendocrine--gonadal function in the intact male laboratory rat, it seems that some component(s) of a photoperiodic system involving the pineal gland has been preserved.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Jan
pubmed:issn
0028-0836
pubmed:author
pubmed:issnType
Print
pubmed:day
29
pubmed:volume
289
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
402-4
pubmed:dateRevised
2007-11-14
pubmed:meshHeading
pubmed:year
1981
pubmed:articleTitle
Photoperiodicity in the male albino laboratory rat.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S., Research Support, U.S. Gov't, Non-P.H.S.