Linked Life Data

1532675

Source:http://linkedlifedata.com/resource/pubmed/id/1532675

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
3
pubmed:dateCreated
1992-5-4
pubmed:abstractText
We used the reversibly binding D2 dopamine receptor radioligand [123I]IBZM (iodobenzamide) to test whether the endogenous neurotransmitter dopamine competes in vivo for radiotracer binding measured with single photon emission computed tomography (SPECT). In a series of nonhuman primate experiments (n = 27), the effects of temperature, amphetamine, haloperidol, and reserpine on brain uptake of [123I]IBZM were measured. Specific brain uptake of [123I]IBZM reached a peak by 100 min postinjection of radioligand and demonstrated a gradual, apparent "steady-state" washout over the next 2 hr. Brain uptake was temperature dependent, with rates of washout of specifically bound radioligand greater under normothermic conditions (26%/hr: core body temperature 35-37 degrees C) than under conditions of controlled hypothermia (11%/hr; 32-34 degrees C). Given the greater retention of radioactivity, low-temperature conditions were used in all other experiments. Administration of haloperidol (0.02 mg/kg IV) during the period of apparent steady state resulted in a dramatic increase in washout (60%/hr; p less than 0.0001), consistent with its potent D2 receptor antagonist properties. d-Amphetamine (1.0 mg/kg IV), which has negligible affinity for the D2 receptor but mediates the release of endogenous stores of dopamine, also enhanced washout (34%/hr; p less than 0.0005). Reserpine pretreatment at doses (1.0 mg/kg) sufficient to cause greater than 90% depletion of striatal dopamine levels blocked this amphetamine-enhanced washout (10%/hr; p less than 0.05). Reserpine did not block the increased washout induced by the direct-acting D2 receptor antagonist haloperidol. These results are consistent with the hypothesis that endogenous dopamine may effectively compete for radioligand binding in vivo in neuroreceptor imaging studies using PET and SPECT.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Mar
pubmed:issn
0887-4476
pubmed:author
pubmed:issnType
Print
pubmed:volume
10
pubmed:owner
NLM
pubmed:authorsComplete
N
pubmed:pagination
177-84
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed-meshheading:1532675-Animals, pubmed-meshheading:1532675-Benzamides, pubmed-meshheading:1532675-Binding, Competitive, pubmed-meshheading:1532675-Brain, pubmed-meshheading:1532675-Cerebral Cortex, pubmed-meshheading:1532675-Corpus Striatum, pubmed-meshheading:1532675-Dextroamphetamine, pubmed-meshheading:1532675-Dopamine, pubmed-meshheading:1532675-Female, pubmed-meshheading:1532675-Haloperidol, pubmed-meshheading:1532675-Iodine Radioisotopes, pubmed-meshheading:1532675-Kinetics, pubmed-meshheading:1532675-Macaca mulatta, pubmed-meshheading:1532675-Male, pubmed-meshheading:1532675-Papio, pubmed-meshheading:1532675-Pyrrolidines, pubmed-meshheading:1532675-Receptors, Dopamine, pubmed-meshheading:1532675-Receptors, Dopamine D2, pubmed-meshheading:1532675-Reserpine, pubmed-meshheading:1532675-Tomography, Emission-Computed
pubmed:year
1992
pubmed:articleTitle
Amphetamine-stimulated dopamine release competes in vivo for [123I]IBZM binding to the D2 receptor in nonhuman primates.
pubmed:affiliation
West Haven VA Medical Center, Connecticut.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, Non-P.H.S., Research Support, Non-U.S. Gov't