Linked Life Data

1795268

Source:http://linkedlifedata.com/resource/pubmed/id/1795268

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:dateCreated
1992-4-7
pubmed:abstractText
Melatonin is thought to play a role in relaying photic information to the central nervous system as part of the seasonal reproductive cycle of the mare. However, the mechanisms by which melatonin may act are unknown. Therefore, this study was designed to determine whether exposure to constant light would, by reducing circulating melatonin concentrations, have any effect on hypothalamic gonadotrophin-releasing hormone (GnRH) content and circulating levels of luteinizing hormone (LH) and follicle-stimulating hormone (FSH). Blood samples were collected for 12 h at 15-min intervals from 8 ovariectomized (OVX) pony mares under ambient light conditions (12 h light, 12 h dark, October 6). Animals were then placed under representative ambient light (12 h light, 12 h dark; control, n = 4) or constant light (24 h light, 0 h dark; treatment, n = 4) in light-controlled rooms. Blood samples were collected daily and on experimental Days 14, 21 and 28 samples were collected at 15-min intervals for 12 h for analysis of circulating LH and melatonin (Bleed 2, 3 and 4, respectively). All animals were killed on Day 28 (following Bleed 4) and the hypothalami were collected. Mares exposed to constant light had significantly higher (P less than 0.05) LH concentrations in daily blood samples and showed significantly (P less than 0.05) higher LH concentrations during frequent sampling periods on Days 14 and 21 (Bleeds 2 and 3) compared with control mares. FSH did not differ significantly among groups in the daily samples. GnRH content was 1.5994 +/- 0.325 and 0.9457 +/- 0.193 pg/mg protein (treatment and control respectively).(ABSTRACT TRUNCATED AT 250 WORDS)
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:issn
0449-3087
pubmed:author
pubmed:issnType
Print
pubmed:volume
44
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
259-66
pubmed:dateRevised
2007-11-14
pubmed:meshHeading
pubmed:year
1991
pubmed:articleTitle
Effect of constant light exposure on circulating gonadotrophin levels and hypothalamic gonadotrophin-releasing hormone (GnRH) content in the ovariectomized pony mare.
pubmed:affiliation
Animal Science Department, University of Florida, Gainesville 32611.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S.