Calculating receptor number from binding experiments using same compound as radioligand and competitor

DeBlasi, Antonio; O’Reilly, Kevin; Motulsky, Harvey J.

doi:10.1016/0165-6147(89)90266-6

Cited by 240 publications

(151 citation statements)

References 3 publications

Supporting

Mentioning

147

Contrasting

Order By: Relevance

“…The total number of binding sites (B max ) and maximal velocity (V max ) were determined according to DeBlasi et al (1989). Two-factor ANOVA was used to analyze strain differences in K i and B max values (strain × brain region).…”

Section: Discussionmentioning

confidence: 99%

Inbred Lewis and Fischer 344 rat strains differ not only in novelty- and amphetamine-induced behaviors, but also in dopamine transporter activity in vivo

2007

View full text Add to dashboard Cite

Inbred Lewis (LEW) and Fischer 344 (F344) rats are differentially sensitive to drugs of abuse, making them useful for studying addiction-related neural mechanisms. Here, we investigated whether strain differences in dopamine transporters (DATs) in dorsal striatum (dSTR) and/or nucleus accumbens (NAc) may help to explain their behavioral differences. The behavior of male LEW and F344 rats was assessed in an open-field arena during habituation to novelty and after an i.v. infusion of saline and/or 0.5 mg/kg d-amphetamine (AMPH). In vitro measures of DAT binding, protein and cellsurface expression, as well as in vitro and in vivo measures of function, were used to compare DATs in dSTR and NAc of these two strains. We found that LEW rats exhibited higher novelty-and AMPHinduced locomotion, but F344 rats exhibited greater AMPH-induced rearing and stereotypy. An initial habituation session with i.v. saline minimized the strain differences in AMPH-induced behaviors except that the more frequent AMPH-induced rearing in F344 rats persisted. Strain differences in DAT total protein and basal activity were also observed, with LEW rats having less protein and slower in vivo clearance of locally-applied DA in dSTR and NAc. AMPH inhibited in vivo DA clearance in dSTR and NAc of both strains, but to a greater extent in F344 rats. Taken together, the lower basal DAT function in LEW rats is consistent with their greater novelty-induced locomotor activation, whereas the greater inhibition of DA clearance by AMPH in F344 rats is consistent with their marked AMPH-induced rearing behavior.

show abstract

Section: Discussionmentioning

confidence: 99%

Inbred Lewis and Fischer 344 rat strains differ not only in novelty- and amphetamine-induced behaviors, but also in dopamine transporter activity in vivo

2007

View full text Add to dashboard Cite

show abstract

“…Radioligand binding data were analyzed with nonlinear curve fitting for one-or two-site binding models to obtain IC 50 and K i values (GraphPad Prism, GraphPad Software, Inc., San Diego, CA). B max values were derived using the formula described by DeBlasi et al (1989). Differences in specific binding of [ 3 H]WIN 35,428 were analyzed by two-way ANOVA (group Â drug concentration), while differences in K i and B max were analyzed with Student's t-test.…”

Section: Discussionmentioning

confidence: 99%

Individual Differences in Cocaine-induced Locomotor Activity in Rats: Behavioral Characteristics, Cocaine Pharmacokinetics, and the Dopamine Transporter

Gulley

Hoover

Larson

et al. 2003

Neuropsychopharmacol

View full text Add to dashboard Cite

Outbred male Sprague-Dawley rats can be classified as either low or high cocaine responders (LCRs or HCRs, respectively) based on their locomotor response to acute cocaine. Concomitant measurement of dopamine clearance in these rats revealed that the differential behavioral responses are associated with the magnitude of dopamine transporter (DAT) inhibition by cocaine. Here, we investigated several factors that might contribute to cocaine-induced behavioral variability and its association with differential inhibition of DAT function. In rats classified as LCRs or HCRs after 10 mg/kg cocaine injection, we found no differences in (1) novelty-induced locomotion, (2) cocaine levels in dorsal striatum or nucleus accumbens (NAc), (3) DAT number or affinity in NAc, or (4) DAT affinity for cocaine in NAc. In rats given 20 mg/kg cocaine, behavior was more uniform across individuals, but still warranted separation into LCR/HCR categories. Additionally, we analyzed the stability of the LCR/HCR classification made during the first test with 10 or 20 mg/kg cocaine by retesting rats 7 days later with saline or cocaine (10 or 20 mg/kg). Before injection, HCRs were more active relative to LCRs and to their own behavior on the first test day. Following cocaine, LCRs and HCRs exhibited similar drug-induced changes in locomotion, but there were unique effects that depended on the cocaine dose given on the first and second test days. Our results argue against several likely explanations for individual differences in cocaine-induced behavior and highlight the influence of a single cocaine exposure on subsequent behavioral responses to the drug.

show abstract

“…The total number of binding sites (B max ) was determined using the formula described by DeBlasi et al (1989 …”

Section: Statistical Analysesmentioning

confidence: 99%

Individual Differences in Cocaine- and Amphetamine-Induced Activation of Male Sprague–Dawley Rats: Contribution of the Dopamine Transporter

Briegleb

Gulley

Hoover

et al. 2004

Neuropsychopharmacol

View full text Add to dashboard Cite

Previously we found that outbred male Sprague-Dawley rats can be classified as either low or high cocaine responders (LCRs or HCRs, respectively), based on their open-field locomotor response to acute cocaine (COC; 10 mg/kg, i.p.). Here, we extended this analysis to amphetamine (AMPH; 0.5, 1, and 5 mg/kg, i.p.) and found that the individual differences in behavioral activation were not as pronounced as with COC. This was confirmed with observational analysis of behaviors. Differences in drug-induced activation could involve differential dopamine transporter (DAT) function/trafficking. To address this possibility, we measured [ 3 H]DA uptake into dorsal striatal synaptosomes prepared from rats injected 30 min earlier with saline, COC, or AMPH to determine DAT activity, and radioligand binding to determine the total number of DATs. Striatal [ 3 H]DA uptake in COC-treated HCRs was significantly higher than in LCRs. Furthermore, regardless of LCR/HCR classification, uptake in individual COC-treated rats was significantly correlated with their locomotor behavior in the 30 min after drug administration. In contrast, AMPH-treated rats did not differ in uptake, nor were uptake and locomotor activity correlated. DAT number did not differ between LCRs or HCRs, or between AMPH-treated rats. In addition, when individual differences in COC-induced behavior were no longer detected in LCRs and HCRs 1 week after initial classification, uptake was also similar. Together, these results suggest that a difference in expression of functional DATs on the cell surface contributes to the individual differences observed in COC-induced, but not AMPH-induced, behavioral activation of rats.

show abstract

Calculating receptor number from binding experiments using same compound as radioligand and competitor

Cited by 240 publications

References 3 publications

Inbred Lewis and Fischer 344 rat strains differ not only in novelty- and amphetamine-induced behaviors, but also in dopamine transporter activity in vivo

Inbred Lewis and Fischer 344 rat strains differ not only in novelty- and amphetamine-induced behaviors, but also in dopamine transporter activity in vivo

Individual Differences in Cocaine-induced Locomotor Activity in Rats: Behavioral Characteristics, Cocaine Pharmacokinetics, and the Dopamine Transporter

Individual Differences in Cocaine- and Amphetamine-Induced Activation of Male Sprague–Dawley Rats: Contribution of the Dopamine Transporter

Contact Info

Product

Resources

About