Linked Life Data

9415065

Source:http://linkedlifedata.com/resource/pubmed/id/9415065

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
2
pubmed:dateCreated
1998-2-2
pubmed:abstractText
We have studied why rat pineal N-acetyltransferase (NAT) activity is relatively insensitive to isoproterenol in young rats when compared with adult rats. We report that activation by isoproterenol of pineal cyclic AMP production and NAT activity is higher in adult than in 2-week-old rats. However, the effect of dibutyryl cyclic AMP, which enters the pinealocyte and duplicates the effect of cyclic AMP, on NAT activity was similar at both ages. Moreover, we found that both alpha- and beta-adrenergic receptors are highly specific at both ages, since the binding of the specific radioligands used to their receptors could be displaced only by their corresponding agonists and antagonists. However, we observed differences between pineals from young and adult rats when several families of the alpha subunit of G-proteins were studied in cell membranes. ADP-ribosylation and immunoblot studies have shown clear differences in both 42 and 45 kDa forms of the Gs alpha Both forms exhibit low values in pineals from 2-week-old animals when compared with 6-week-old. We also show that the later appearance of both Gs alpha forms is roughly similar to the potent activation of cyclic AMP production and NAT activity in adult rats when compared with young rats. In conclusion, the results presented suggest that the relative lack of sensitivity of rat pineal gland to beta-adrenergic receptor agonists early in the postnatal development may be explained by the low levels of membrane Gs alpha, rather than postreceptor-mediated mechanisms or changes in the characteristics of the beta-adrenergic receptors on the pinealocyte membrane.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Nov
pubmed:issn
0022-0795
pubmed:author
pubmed:issnType
Print
pubmed:volume
155
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
305-12
pubmed:dateRevised
2009-11-19
pubmed:meshHeading
pubmed-meshheading:9415065-Adrenergic alpha-Agonists, pubmed-meshheading:9415065-Adrenergic beta-Agonists, pubmed-meshheading:9415065-Adrenergic beta-Antagonists, pubmed-meshheading:9415065-Aging, pubmed-meshheading:9415065-Animals, pubmed-meshheading:9415065-Animals, Newborn, pubmed-meshheading:9415065-Arylamine N-Acetyltransferase, pubmed-meshheading:9415065-Binding, Competitive, pubmed-meshheading:9415065-Bucladesine, pubmed-meshheading:9415065-Cyclic AMP, pubmed-meshheading:9415065-Female, pubmed-meshheading:9415065-GTP-Binding Protein alpha Subunits, Gi-Go, pubmed-meshheading:9415065-GTP-Binding Protein alpha Subunits, Gs, pubmed-meshheading:9415065-Isoproterenol, pubmed-meshheading:9415065-Male, pubmed-meshheading:9415065-Methoxamine, pubmed-meshheading:9415065-Organ Culture Techniques, pubmed-meshheading:9415065-Pineal Gland, pubmed-meshheading:9415065-Propranolol, pubmed-meshheading:9415065-Protein Binding, pubmed-meshheading:9415065-Rats, pubmed-meshheading:9415065-Rats, Wistar
pubmed:year
1997
pubmed:articleTitle
Differential adrenergic regulation of rat pineal cyclic AMP production and N-acetyltransferase activity during postnatal development: involvement of G alpha s and G alpha i1-2 proteins.
pubmed:affiliation
Department of Medical Biochemistry and Molecular Biology, University of Seville School of Medicine, Spain.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't