Linked Life Data

2892105

Source:http://linkedlifedata.com/resource/pubmed/id/2892105

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
1
pubmed:dateCreated
1988-2-18
pubmed:abstractText
The effects of new Agmatine (Agm) analogs of human growth hormone-releasing hormone (GH-RH) were compared to GH-RH (1-29)NH2 and to (D-Ala2)GH-RH(1-29)NH2 after intravenous (IV) and subcutaneous (SC) administration to pentobarbital-anesthetised male rats and in vitro using superfused rat pituitary cell system. After IV administration, the analogs: (D-MeAla2,Nle27)GH-RH(1-28)Agm(JG-75), (desamino-Tyr1,D-Ala2,Nle27)GH-RH(1-28)Agm(JG-77), (D-Ala2,Nle27)GH-RH(1-28)Agm(JG-73) and (D-Ala2)GH-RH(1-29)NH2 showed a potency 2.6-3.9 times greater than GH-RH(1-29)NH2 at 5 min and 1.6-2.7 times higher at 15 min. After SC administration these analogs were 30-74 times more potent than GH-RH(1-29)NH2. The ratio between the IV and SC GH-releasing activity of the analogs ranged from 2 to 5, while GH-RH(1-29)NH2 was about 50 times more active IV than SC. This indicates that 20-50% of the analogs can be absorbed from SC tissues, but only 2% of GH-RH(1-29)NH2. The in vitro activity of the agmatine analogs on GH release closely paralleled their IV potency and was 2.8-3.9 times greater than that of GH-RH(1-29)NH2. No significant difference in potency was found between (D-Ala2)GH-RH(1-29)NH2 and JG-75 after IV administration and in vitro, although JG-75 contained only 28 amino acids. We conclude that the reason for the large discrepancies between the previously reported activities of (D-Ala2)GH-RH(1-29)NH2 was simply due to the different ways of administration of this analog, SC vs IV, and not to species specificity. The replacement of Arg29 by Agmatine in (D-Ala2,Nle27)GH-RH(1-29)NH2 causes a 3 fold increase in SC potency, but the replacement of D-Ala2 with D-MeAla2 reduces the SC, but not the IV and in vitro activity in half.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:issn
0024-3205
pubmed:author
pubmed:issnType
Print
pubmed:volume
42
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
27-35
pubmed:dateRevised
2007-11-14
pubmed:meshHeading
pubmed:year
1988
pubmed:articleTitle
An evaluation of intravenous, subcutaneous, and in vitro activity of new agmatine analogs of growth hormone-releasing hormone hGH-RH (1-29)NH2.
pubmed:affiliation
Department of Medicine, Tulane University School of Medicine, New Orleans, Louisiana 70146.
pubmed:publicationType
Journal Article, In Vitro, Research Support, U.S. Gov't, P.H.S., Research Support, U.S. Gov't, Non-P.H.S., Research Support, Non-U.S. Gov't