Linked Life Data

8321419

Source:http://linkedlifedata.com/resource/pubmed/id/8321419

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
3
pubmed:dateCreated
1993-7-30
pubmed:abstractText
Glutamate and aspartate have been hypothesized to function as neurotransmitters in the regulation of the gonadotropin-releasing hormone (GnRH) neurosecretory system. We, therefore, determined if hypothalamic stimulation of luteinizing hormone (LH) secretion in the intact prepubertal female lamb could be achieved by intravenous injection of N-methyl-D,L-aspartate (NMA), a glutamate agonist. A pilot study determined a dose of NMA that would induce physiologic pulses of LH (GnRH). Subsequently, we compared the ability of NMA with exogenous GnRH to induce ovulation in the prepubertal lamb when administered chronically. Eighteen prepubertal lambs (21 weeks of age, 34.2 +/- 1.5 kg body weight) were treated intravenously with either NMA (2 mg/kg, n = 6) or GnRH (68 ng/injection or approximately 2 ng/kg, n = 6) for 3 days, every 2 h on day 1 and every 1 h on days 2 and 3, or received no treatment (controls, n = 6). Gonadotropin surges were detected only in GnRH-treated lambs (5/6 lambs, onset = 54.0 +/- 4.5 h from the start of study, mean +/- SE). Compared to 83% of GnRH injections inducing LH pulses, only 47% of NMA injections induced LH pulses. Because each injection of NMA did not induce a pulse of LH, a second experiment was performed in an attempt to optimize the LH response to NMA. Ten prepubertal lambs (25 weeks of age) were injected every 2 h for 24 h with higher doses of NMA, either 4 mg/kg (n = 5) or 16 mg/kg (n = 5).(ABSTRACT TRUNCATED AT 250 WORDS)
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Mar
pubmed:issn
0028-3835
pubmed:author
pubmed:issnType
Print
pubmed:volume
57
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
467-75
pubmed:dateRevised
2007-11-14
pubmed:meshHeading
pubmed:year
1993
pubmed:articleTitle
Hypothalamic versus pituitary stimulation of luteinizing hormone secretion in the prepubertal female lamb.
pubmed:affiliation
Department of Obstetrics and Gynecology, University of Michigan, Ann Arbor 48109-0404.
pubmed:publicationType
Journal Article, Comparative Study, Research Support, U.S. Gov't, P.H.S., Research Support, U.S. Gov't, Non-P.H.S.