Linked Life Data

1326606

Source:http://linkedlifedata.com/resource/pubmed/id/1326606

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
9
pubmed:dateCreated
1992-10-19
pubmed:abstractText
It is generally accepted that the bicuculline-resistant responses to GABA are mediated through the activation of GABAB receptors that mediate a slow IPSP. However, a number of reported observations are difficult to reconcile with this model. Specifically, GABAB antagonists only partially block bicuculline-resistant GABA responses, and both 4-aminopyridine (4-AP) and carbachol have been reported to block responses to the selective GABAB agonist baclofen, but not GABA itself. Thus, it has been argued that baclofen and GABA increase potassium conductance through separate receptor mechanisms. This suggestion is not easily reconcilable with the postulated physiological role of GABAB receptors in mediating the slow IPSP. We have addressed these discrepancies by using the new GABAB antagonists 2-hydroxy-saclofen (2-OH-SAC) and CGP 35348 in the presence of the GABA uptake inhibitor SKF 89976A. The weak antagonism of 2-OH-SAC against the bicuculline-resistant GABA response was improved when the GABA uptake was inhibited with SKF 89976A, allowing for the application of lower GABA concentrations. Under these circumstances, 2-OH-SAC and CGP 35348 strongly antagonized GABA and baclofen responses, but did not have any effect on outward currents evoked by 5-HT. The slow IPSP evoked in the presence of glutamate antagonists was reversibly inhibited by CGP 35348 (IC50 = 14 microM), without affecting the fast IPSP. Carbachol (0.3-20 microM) had no effect on outward currents evoked by either baclofen or GABA. 4-AP (5 microM to 1 mM), despite causing a large increase in cell excitability, did not change baclofen responses. Higher concentrations of 4-AP (5 mM) induced inward current, and reduced both baclofen and GABA outward currents to a similar extent.(ABSTRACT TRUNCATED AT 250 WORDS)
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Sep
pubmed:issn
0270-6474
pubmed:author
pubmed:issnType
Print
pubmed:volume
12
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
3466-72
pubmed:dateRevised
2007-11-14
pubmed:meshHeading
pubmed:year
1992
pubmed:articleTitle
Pharmacological characterization of GABAB-mediated responses in the CA1 region of the rat hippocampal slice.
pubmed:affiliation
Department of Pharmacology, University of California, San Francisco 94143-0450.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S., Research Support, Non-U.S. Gov't