Linked Life Data

6707931

Source:http://linkedlifedata.com/resource/pubmed/id/6707931

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
1
pubmed:dateCreated
1984-5-23
pubmed:abstractText
Propranolol is accumulated at several adrenergic neuroeffector junctions after chronic oral administration in the dog, and is released subsequently during sympathetic nerve stimulation. In the present study, the accumulation, subcellular localization and release of propranolol was examined in rat cortical synaptosomes. Synaptosomal propranolol accumulation was rapid and attained equilibrium within 1 min. Propranolol uptake increased in a nonlinear manner with increasing drug concentration in the medium, but could not be fully saturated over the concentration range studied (10(-7) - 10(-3) M). Uptake was unaffected by cocaine or ouabain and showed no stereoselectivity. Subsynaptosomal fractionation of propranolol-loaded synaptosomes revealed that the drug was concentrated principally in fractions enriched in synaptic plasma membranes and synaptic storage vesicles. Exposure of propranolol-loaded synaptosomes to elevated potassium evoked a concentration-dependent increase in propranolol overflow, which was not seen in mitochondrial fractions, myelin fractions or in freeze-thawed synaptosomal preparations. Veratridine was also effective in promoting propranolol overflow in a concentration-dependent manner. The increase in propranolol overflow induced by elevated potassium was significantly reduced, but not completely inhibited, in a calcium-free, ethylene glycol bis(beta-aminoethyl ether)-N,N'-tetraacetic acid-supplemented medium. These results indicate that propranolol may be accumulated by neuronal tissue and stored at sites from which release may occur in response to depolarizing stimuli. The data further suggest that propranolol release in the synaptosome preparation may occur by both calcium-dependent and calcium-independent processes.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Apr
pubmed:issn
0022-3565
pubmed:author
pubmed:issnType
Print
pubmed:volume
229
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
154-61
pubmed:dateRevised
2008-11-21
pubmed:meshHeading
pubmed:year
1984
pubmed:articleTitle
Accumulation, subcellular localization and release of propranolol from synaptosomes of rat cerebral cortex.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S., Research Support, Non-U.S. Gov't