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| Predicate | Object |
|---|---|
| rdf:type | |
| lifeskim:mentions | |
| pubmed:issue |
1
|
| pubmed:dateCreated |
1986-2-5
|
| pubmed:abstractText |
In fish there are few data on the gonadotropin-releasing hormone (Gn-RH) neurosecretory activity, which could explain long- and short-term variations of the gonadotropin secretion. There is no biological species specificity between mammal and fish Gn-RH; although there is a structural difference, they are, on the contrary, characterized by a high immunological specificity which does not allow measurement of fish Gn-RH using radioimmunoassay for LH-RH. We have synthesized salmon Gn-RH according to the formula recently proposed by Sherwood (N. Sherwood, L. Eiden, M. Brownstein, J. Spies, J. Rivier, and W. Vale, 1983. Proc. Natl. Acad. Sci. USA 80, 2794-2798). Its activity has been tested by its ability to stimulate the gonadotropin hormone (GtH) secretion in vivo in testosterone-implanted juvenile rainbow trout, and for the recognition of synthesized Gn-RH (s-Gn-RH) perykaria by a specific antibody raised against the s-Gn-RH in regions of the brain described as containing LH-RH immunoreactive-like material. A radioimmunoassay has been developed for the salmon Gn-RH, and its specificity to measure trout Gn-RH has been tested. Using this assay, the brain and pituitary Gn-RH contents have been measured throughout the final phases of maturation and ovulation. Brain Gn-RH increases from the end of vitellogenesis (8.9 +/- 0.76 ng/brain) to ovulation (more than 15 ng/brain). Pituitary Gn-RH is lower (1.58 +/- 0.69 ng/pituitary) at the end of vitellogenesis and follows a similar profile as in the brain, except for a significant decrease just prior the beginning of oocyte maturation. The correlations between Gn-RH levels and GtH pituitary and plasma levels show that total brain Gn-RH is never correlated to the GtH, suggesting that the increase in the brain Gn-RH content is related to a Gn-RH system closely related to maturation and ovulation, which remains to be investigated. On the contrary, pituitary Gn-RH levels are well correlated with pituitary and plasma GtH levels, indicating that pituitary Gn-RH levels might represent a good index of the Gn-RH neurosecretory activity in the fish hypothalamohypophysial complex, given the absence of a portal system in teleost.
|
| pubmed:language |
eng
|
| pubmed:journal | |
| pubmed:citationSubset |
IM
|
| pubmed:chemical | |
| pubmed:status |
MEDLINE
|
| pubmed:month |
Jan
|
| pubmed:issn |
0016-6480
|
| pubmed:author | |
| pubmed:issnType |
Print
|
| pubmed:volume |
61
|
| pubmed:owner |
NLM
|
| pubmed:authorsComplete |
Y
|
| pubmed:pagination |
109-19
|
| pubmed:dateRevised |
2006-11-15
|
| pubmed:meshHeading |
pubmed-meshheading:3510150-Animals,
pubmed-meshheading:3510150-Brain Chemistry,
pubmed-meshheading:3510150-Chromatography, High Pressure Liquid,
pubmed-meshheading:3510150-Female,
pubmed-meshheading:3510150-Gonadotropin-Releasing Hormone,
pubmed-meshheading:3510150-Gonadotropins,
pubmed-meshheading:3510150-Ovulation,
pubmed-meshheading:3510150-Pituitary Gland,
pubmed-meshheading:3510150-Radioimmunoassay,
pubmed-meshheading:3510150-Salmonidae,
pubmed-meshheading:3510150-Testosterone,
pubmed-meshheading:3510150-Trout
|
| pubmed:year |
1986
|
| pubmed:articleTitle |
Immunoreactive gonadotropin-releasing hormone-like material in the brain and the pituitary gland during the periovulatory period in the brown trout (Salmo trutta L.): relationships with the plasma and pituitary gonadotropin.
|
| pubmed:publicationType |
Journal Article,
Comparative Study,
Research Support, Non-U.S. Gov't
|