Linked Life Data

6352246

Source:http://linkedlifedata.com/resource/pubmed/id/6352246

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
4
pubmed:dateCreated
1983-11-23
pubmed:abstractText
Results from previous investigations have suggested an important role for central epinephrine (EPI) systems in mediating the stimulatory effects of ovarian hormones on LH release in ovariectomized female rats. The purpose of these experiments was 1) to test whether selective inhibition of EPI synthesis blocks the sequential accumulation and decline of LHRH concentrations in the median eminence that precedes the ovarian hormone-induced LH surge and 2) to test whether the stimulatory ovarian hormone regimen enhances the activity of EPI systems in the hypothalamus. Ovariectomized rats were treated with estradiol, followed 2 days later by progesterone. Animals were treated before progesterone administration with saline, one of the EPI synthesis inhibitors [SK&F 64139 (2,3-dichloro-tetrahydroisoquinoline HCl) or LY 78335 (dichloro-alpha-methylbenzylamine)], or the dopamine-beta-hydroxylase inhibitor FLA-63 (bis-4-methyl-1-homopiperazinyl thiocarbonyl disulfide), which inhibits NE and EPI synthesis. The catecholamine synthesis inhibitors blocked or delayed the afternoon LH surge. FLA-63 completely prevented the accumulation of LHRH in the median eminence that preceded the rise in LH release. However, selective EPI synthesis inhibition with SK&F 64139 only partially prevented this increase in LHRH. A second EPI synthesis inhibitor, LY 78335, delayed both the LH surge and the rise in LHRH. In a second experiment, the administration of estradiol and progesterone to ovariectomized rats increased the alpha-methyltyrosine-induced depletion of hypothalamic EPI, suggesting increased activity in this system during the LH surge. Further experiments localized this effect to the medial basal hypothalamus. The depletion of both NE and EPI after synthesis inhibition was also enhanced during an earlier period, approximating the time of LHRH accumulation. These results suggest that the ovarian hormones activate both NE and EPI systems to stimulate the early afternoon rise of LHRH in the median eminence and to induce the subsequent LH surge.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
AIM
pubmed:chemical
http://linkedlifedata.com/resource/pubmed/chemical/2,3-dichloro-alpha-methylbenzylamine, http://linkedlifedata.com/resource/pubmed/chemical/7,8-dichloro-1,2,3,4-tetrahydroisoqu..., http://linkedlifedata.com/resource/pubmed/chemical/Benzylamines, http://linkedlifedata.com/resource/pubmed/chemical/Bis(4-Methyl-1-Homopiperazinylthioca..., http://linkedlifedata.com/resource/pubmed/chemical/Dopamine beta-Hydroxylase, http://linkedlifedata.com/resource/pubmed/chemical/Epinephrine, http://linkedlifedata.com/resource/pubmed/chemical/Estradiol, http://linkedlifedata.com/resource/pubmed/chemical/Gonadotropin-Releasing Hormone, http://linkedlifedata.com/resource/pubmed/chemical/Isoquinolines, http://linkedlifedata.com/resource/pubmed/chemical/Luteinizing Hormone, http://linkedlifedata.com/resource/pubmed/chemical/Norepinephrine, http://linkedlifedata.com/resource/pubmed/chemical/Phenylethanolamine..., http://linkedlifedata.com/resource/pubmed/chemical/Progesterone, http://linkedlifedata.com/resource/pubmed/chemical/Tetrahydroisoquinolines
pubmed:status
MEDLINE
pubmed:month
Oct
pubmed:issn
0013-7227
pubmed:author
pubmed:issnType
Print
pubmed:volume
113
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
1431-8
pubmed:dateRevised
2007-11-14
pubmed:meshHeading
pubmed:year
1983
pubmed:articleTitle
Evidence that norepinephrine and epinephrine systems mediate the stimulatory effects of ovarian hormones on luteinizing hormone and luteinizing hormone-releasing hormone.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S.