Switch to
| Predicate | Object |
|---|---|
| rdf:type | |
| lifeskim:mentions | |
| pubmed:issue |
5 Pt 2
|
| pubmed:dateCreated |
1988-12-14
|
| pubmed:abstractText |
Testis growth is stimulated when short photoperiod-regressed Siberian hamsters are exposed to a lengthening photoperiod, an effect presumably mediated by the pineal gland through a decrease in the peak nocturnal duration of secretion of its hormone melatonin (MEL)(D. S. Carter and B. D. Goldman, Endocrinology 113: 1268-1273, 1983). We examined this stimulatory or "progonadal" effect of MEL in short photoperiod-regressed, adult male Siberian hamsters that were pinealectomized (PINX) and given timed daily subcutaneous 1) injections of MEL (1 or 10 micrograms/day) or saline or 2) infusions of MEL that were "long day-like" (4 h, 10 or 100 ng/day), "short day-like" (10 h, 10 ng/day), or control saline infusions (4 h/day). Photoregressed sham PINX hamsters were transferred to long days at this time. After 5 wk of treatment, 1-microgram MEL-injected hamsters and both groups of 4-h MEL-infused hamsters had stimulatory responses that mimicked those of the long-day-exposed, sham PINX group [i.e., increased testes, body, and epididymal white adipose tissue (EPIWAT) weights, total body fat, EPIWAT lipoprotein lipase activity, and serum prolactin and follicle-stimulating hormone levels]. These effects were not observed in 10-micrograms MEL- or saline-injected and 10-h MEL- or saline-infused hamsters. Thus the peak nocturnal duration of serum MEL is the critical parameter of the MEL secretion profile for stimulating a variety of photoperiodic responses when photoregressed hamsters are exposed to lengthening daylengths.
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| pubmed:grant | |
| pubmed:language |
eng
|
| pubmed:journal | |
| pubmed:citationSubset |
IM
|
| pubmed:chemical | |
| pubmed:status |
MEDLINE
|
| pubmed:month |
Nov
|
| pubmed:issn |
0002-9513
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| pubmed:author | |
| pubmed:issnType |
Print
|
| pubmed:volume |
255
|
| pubmed:owner |
NLM
|
| pubmed:authorsComplete |
Y
|
| pubmed:pagination |
R823-30
|
| pubmed:dateRevised |
2007-11-14
|
| pubmed:meshHeading |
pubmed-meshheading:3142282-Adipose Tissue,
pubmed-meshheading:3142282-Adipose Tissue, Brown,
pubmed-meshheading:3142282-Animals,
pubmed-meshheading:3142282-Body Composition,
pubmed-meshheading:3142282-Body Weight,
pubmed-meshheading:3142282-Circadian Rhythm,
pubmed-meshheading:3142282-Cricetinae,
pubmed-meshheading:3142282-Epididymis,
pubmed-meshheading:3142282-Follicle Stimulating Hormone,
pubmed-meshheading:3142282-Light,
pubmed-meshheading:3142282-Lipoprotein Lipase,
pubmed-meshheading:3142282-Male,
pubmed-meshheading:3142282-Melatonin,
pubmed-meshheading:3142282-Organ Size,
pubmed-meshheading:3142282-Periodicity,
pubmed-meshheading:3142282-Pineal Gland,
pubmed-meshheading:3142282-Prolactin,
pubmed-meshheading:3142282-Reproduction,
pubmed-meshheading:3142282-Testis
|
| pubmed:year |
1988
|
| pubmed:articleTitle |
Effects of melatonin on long-day responses in short-day housed adult Siberian hamsters.
|
| pubmed:affiliation |
Worcester Foundation for Experimental Biology, Shrewsbury, Massachusetts 01545.
|
| pubmed:publicationType |
Journal Article,
Research Support, U.S. Gov't, P.H.S.
|