scholarly journals Comparison of [11C]Diprenorphine and [11C]Carfentanil Binding to Opiate Receptors in Humans by Positron Emission Tomography

1990 ◽  
Vol 10 (4) ◽  
pp. 484-492 ◽  
Author(s):  
J. James Frost ◽  
Helen S. Mayberg ◽  
Bernard Sadzot ◽  
Robert F. Dannals ◽  
John R. Lever ◽  
...  
Keyword(s):  
Positron Emission Tomography ◽  
Specific Binding ◽  
Regional Distribution ◽  
Opiate Receptors ◽  
Opiate Receptor ◽  
Total Radioactivity ◽  
Emission Tomography ◽  
Receptor Subtypes ◽  
Positron Emission ◽  
Kinetics Of

The kinetics and regional distribution of [11C]carfentanil, a μ-selective opiate receptor agonist, and [11C]diprenorphine, a nonselective opiate receptor antagonist, were compared using paired positron emission tomography studies in two normal volunteers. Kinetics of total radioactivity (counts/mCi/pixel) was greater for [11C]diprenorphine than [11C]carfentanil in all regions. [11C]Carfentanil binding (expressed as the total/nonspecific ratio) reached near equilibrium at ∼40 min, whereas [11C]diprenorphine showed a linear increase until ∼60 min. Kinetics of specific binding demonstrated significant dissociation of [11C]carfentanil from opiate receptors, whereas little dissociation of [11C]diprenorphine was observed during the 90-min scan session. Regional distributions of [11C]carfentanil and [11C]diprenorphine were qualitatively and quantitatively different: Relative to the thalamus (a region with known predominance of μ-receptors), [11C]diprenorphine displayed greater binding in the striatum and cingulate and frontal cortex compared to [11C]carfentanil, consistent with labeling of additional, non-μ sites by [11C]diprenorphine. We conclude from these studies that [11C]diprenorphine labels other opiate receptor subtypes in addition to the μ sites selectively labeled by [11C]carfentanil. The nonselective nature of diprenorphine potentially limits its usefulness in defining abnormalities of specific opiate receptor subtypes in various diseases. Development of selective tracers for the δ- and κ-opiate receptor sites, or alternatively use of unlabeled inhibitors to differentially displace μ, δ, and κ subtypes, will help offset these limitations.

scholarly journals Noninvasive and Quantitative Monitoring of the Distributions and Kinetics of MicroRNA-Targeting Molecules in Vivo by Positron Emission Tomography

2019 ◽  
Vol 16 (4) ◽  
pp. 1507-1515 ◽  
Author(s):  
Jussi Mäkilä ◽  
Anu Kiviniemi ◽  
Tiina Saanijoki ◽  
Heidi Liljenbäck ◽  
Meeri Käkelä ◽  
...  
Keyword(s):  
Positron Emission Tomography ◽  
Emission Tomography ◽  
Positron Emission ◽  
Quantitative Monitoring ◽  
Kinetics Of

A Double-Injection Technique for in vivo Measurement of Dopamine D2-Receptor Density in Monkeys with 3-(2'-[18F] Fluoroethyl)Spiperone and Dynamic Positron Emission Tomography

1989 ◽  
Vol 9 (6) ◽  
pp. 850-858 ◽  
Author(s):  
Sung-Cheng Huang ◽  
Mark M. Bahn ◽  
Jorge R. Barrio ◽  
John M. Hoffman ◽  
Nagichettiar Satyamurthy ◽  
...  
Keyword(s):  
Positron Emission Tomography ◽  
Receptor Binding ◽  
Dopamine D2 Receptor ◽  
D2 Receptor ◽  
Emission Tomography ◽  
Injection Technique ◽  
Receptor Density ◽  
Dopamine D2 ◽  
Positron Emission ◽  
Kinetics Of

Dopamine D2-receptor density in striatum of monkey was measured with 3-(2'-[18F]fluoroethyl)spiperone (FESP) and dynamic positron emission tomography (PET), using a double-injection technique. A first bolus of high specific activity (SA) FESP (5 mCi; ≃ 1 Ci/μmol) was injected i.v.; 90 min later, a second bolus of lower SA FESP (5 mCi; ≃ 0.04 Ci/μmol) was injected. A dynamic PET study was performed to measure the kinetics of FESP in striatum over 180 min, and the metabolite-corrected concentration of FESP in plasma as a function of time was obtained from arterial blood samples. A nonlinear compartmental model that took into account the saturability of the receptor binding was used to describe the kinetics of FESP in striatum. Model parameters were estimated by regression with a constraint based on information about the equilibrium dissociation constant of the ligand–receptor binding. Dopamine D2-receptor density in striatum was estimated to be 25.9 ± 12.7 pmol/g in seven Macaca nemestrina monkeys. The method does not require the use of cerebellum as a reference tissue region and an estimate of dopamine D2-receptor density can be obtained from a single study.

scholarly journals Muscarinic Cholinergic Receptor Measurements with [18F]FP-TZTP: Control and Competition Studies

1998 ◽  
Vol 18 (10) ◽  
pp. 1130-1142 ◽  
Author(s):  
Richard E. Carson ◽  
Dale O. Kiesewetter ◽  
Elaine Jagoda ◽  
Margaret G. Der ◽  
Peter Herscovitch ◽  
...  
Keyword(s):  
Positron Emission Tomography ◽  
Basal Ganglia ◽  
Specific Binding ◽  
Emission Tomography ◽  
Ache Inhibitor ◽  
Parameter Estimates ◽  
Tracer Injection ◽  
Positron Emission ◽  
Muscarinic Cholinergic

[18F]Fluoropropyl-TZTP (FP-TZTP) is a subtype-selective muscarinic cholinergic ligand with potential suitability for studying Alzheimer's disease. Positron emission tomography studies in isofluorane-anesthetized rhesus monkeys were performed to assess the in vivo behavior of this radiotracer. First, control studies (n = 11) were performed to characterize the tracer kinetics and to choose an appropriate model using a metabolite-corrected arterial input function. Second, preblocking studies (n = 4) with unlabeled FP-TZTP were used to measure nonspecific binding. Third, the sensitivity of [18F]FP-TZTP binding to changes in brain acetylcholine (ACh) was assessed by administering physostigmine, an acetylcholinesterase (AChE) inhibitor, by intravenous infusion (100 to 200 μg·kg−1·h−1) beginning 30 minutes before tracer injection (n = 7). Tracer uptake in the brain was rapid with K1 values of 0.4 to 0.6 mL·min−1·mL−1 in gray matter. A model with one tissue compartment was chosen because reliable parameter estimates could not be obtained with a more complex model. Volume of distribution ( V) values, determined from functional images created by pixel-by-pixel fitting, were very similar in cortical regions, basal ganglia, and thalamus, but significantly lower ( P < 0.01) in the cerebellum, consistent with the distribution of M2 cholinergic receptors. Preblocking studies with unlabeled FP-TZTP reduced V by 60% to 70% in cortical and subcortical regions. Physostigmine produced a 35% reduction in cortical specific binding ( P < 0.05), consistent with increased ACh competition. The reduction in basal ganglia (12%) was significantly smaller ( P < 0.05), consistent with its markedly higher AChE activity. These studies indicate that [18F]FP-TZTP should be useful for the in vivo measurement of muscarinic receptors with positron emission tomography.

Kinetics of 11C-Labeled Opiates Studied with Positron Emission Tomography in the Brain of the Rhesus Monkey

1985 ◽  
pp. 97-100
Author(s):  
P. O. Lundberg ◽  
P. Hartvig ◽  
K. Bergström ◽  
B. Lindberg ◽  
H. Lundqvist ◽  
...  
Keyword(s):  
Positron Emission Tomography ◽  
Rhesus Monkey ◽  
Emission Tomography ◽  
Positron Emission ◽  
Kinetics Of ◽  
The Brain

Regional lung water and hematocrit determined by positron emission tomography

1985 ◽  
Vol 59 (3) ◽  
pp. 860-868 ◽  
Author(s):  
D. P. Schuster ◽  
M. A. Mintun ◽  
M. A. Green ◽  
M. M. Ter-Pogossian
Keyword(s):  
Positron Emission Tomography ◽  
Regional Distribution ◽  
Vertical Gradient ◽  
Emission Tomography ◽  
Lung Water ◽  
Average Value ◽  
Positron Emission ◽  
Significant Difference ◽  
Regional Basis ◽  
The Difference

We have measured with positron emission tomography (PET) the regional distribution of extravascular lung water (EVLW) and hematocrit (HctL) in normal supine dogs. H2(15)O and C15O were used as total lung water (TLW) and intravascular water (IVW) compartment labels, respectively. An additional plasma volume label (68Ga-transferrin) was used to determine regional HctL. EVLW was calculated as the difference between TLW and IVW. In 13 dogs, EVLW was relatively constant along a gravity-dependent vertical gradient, although values in the most anterior regions were statistically less (P less than 0.05) than those in more posterior ones. The average value for EVLW (13 dogs) was 14.4 +/- 2.5 ml H2O/100 ml lung. When EVLW was compared with IVW on a regional basis, the EVLW/IVW ratio decreased significantly in a gravity-dependent direction from 1.95 +/- 0.28 to 0.88 +/- 0.18. In 7 dogs, no significant difference between HctL and systemic hematocrit (average ratio 1.01 +/- 0.08) was found nor was any significant variation of HctL within the lung detected. Thus, in contrast to gravimetric techniques, a hematocrit correction does not appear to be necessary when regional EVLW is studied by PET.

scholarly journals Positron Emission Tomography Study of Brain Benzodiazepine Receptors in Friedreich's Ataxia

1990 ◽  
Vol 17 (4) ◽  
pp. 404-409 ◽  
Author(s):  
C. Chavoix ◽  
Y. Samson ◽  
S. Pappata ◽  
C. Prenant ◽  
M. Mazière ◽  
...  
Keyword(s):  
Positron Emission Tomography ◽  
Benzodiazepine Receptors ◽  
Friedreich’S Ataxia ◽  
Friedreich's Ataxia ◽  
Emission Tomography ◽  
Tracer Injection ◽  
Central Type ◽  
Positron Emission ◽  
Specific Antagonist ◽  
Kinetics Of

ABSTRACT:Central type benzodiazepine receptors were studied in 9 patients with Friedreich's ataxia and 12 healthy subjects using positron emission tomography (PET) and [11C]Ro 15-1788, a specific antagonist of the central type benzodiazepine receptors, as radioligand. A standard PET procedure was used in 5 patients and 8 controls to obtain brain kinetics of the total binding of the radioligand. The remaining subjects were intravenously injected with a saturating dose of unlabeled Ro 15-1788, 30 minutes after the tracer injection, to determine the nondisplaceable binding of [11C]Ro 15-1788. A semi-quantitative method was used to quantify the [11C]Ro 15-1788 data. None of the quantification indices in the cerebellar hemispheres, or in the other brain areas investigated, was significantly modified in patients with Friedreich's ataxia. These findings suggest that brain benzodiazepine receptors are unaffected in Friedreich's ataxia.

scholarly journals Quantitation of Translocator Protein Binding in Human Brain with the Novel Radioligand [18F]-FEPPA and Positron Emission Tomography

2011 ◽  
Vol 31 (8) ◽  
pp. 1807-1816 ◽  
Author(s):  
Pablo M Rusjan ◽  
Alan A Wilson ◽  
Peter M Bloomfield ◽  
Irina Vitcu ◽  
Jeffrey H Meyer ◽  
...  
Keyword(s):  
Positron Emission Tomography ◽  
Human Brain ◽  
Specific Binding ◽  
Compartment Model ◽  
Distribution Volume ◽  
Translocator Protein ◽  
Emission Tomography ◽  
Binding Potential ◽  
Specific Distribution ◽  
Positron Emission

This article describes the kinetic modeling of [18F]-FEPPA binding to translocator protein 18 kDa in the human brain using high-resolution research tomograph (HRRT) positron emission tomography. Positron emission tomography scans were performed in 12 healthy volunteers for 180 minutes. A two-tissue compartment model (2-CM) provided, with no exception, better fits to the data than a one-tissue model. Estimates of total distribution volume ( VT), specific distribution volume ( VS), and binding potential ( BPND) demonstrated very good identifiability (based on coefficient of variation ( COV)) for all the regions of interest (ROIs) in the gray matter ( COV VT < 7%, COV VS < 8%, COV BPND < 11%). Reduction of the length of the scan to 2 hours is feasible as VS and VT showed only a small bias (6% and 7.5%, respectively). Monte Carlo simulations showed that, even under conditions of a 500% increase in specific binding, the identifiability of VT and VS was still very good with COV<10%, across high-uptake ROIs. The excellent identifiability of VT values obtained from an unconstrained 2-CM with data from a 2-hour scan support the use of VT as an appropriate and feasible outcome measure for [18F]-FEPPA.

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