Synthesis of [11C]iodomethane by iodination of [11C]methane

Larsen, Per; Ulin, Johan; Dahlstrøm, Kent; Jensen, Mikael

doi:10.1016/s0969-8043(96)00177-7

Cited by 236 publications

(153 citation statements)

References 7 publications

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“…The BMI range was 37.1-49.3 kg/m 2 . The obese subjects were compared with 14 healthy nonobese female subjects (mean BMI, 22.7 kg/m 2 ; mean age, 44.9 years) that were age and height matched with the obese subjects ( (Larsen et al, 1997) and converted on-line into […”

Section: Methodsmentioning

confidence: 99%

Obesity Is Associated with Decreased μ-Opioid But Unaltered Dopamine D₂Receptor Availability in the Brain

et al. 2015

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Neurochemical pathways involved in pathological overeating and obesity are poorly understood. Although previous studies have shown increased -opioid receptor (MOR) and decreased dopamine D 2 receptor (D 2 R) availability in addictive disorders, the role that these systems play in human obesity still remains unclear. We studied 13 morbidly obese women [mean body mass index (BMI), 42 kg/m 2 ] and 14 nonobese age-matched women, and measured brain MOR and D 2 R availability using PET with selective radioligands [11 C]carfentanil and [11 C]raclopride, respectively. We also used quantitative meta-analytic techniques to pool previous evidence on the effects of obesity on altered D 2 R availability. Morbidly obese subjects had significantly lower MOR availability than control subjects in brain regions relevant for reward processing, including ventral striatum, insula, and thalamus. Moreover, in these areas, BMI correlated negatively with MOR availability. Striatal MOR availability was also negatively associated with self-reported food addiction and restrained eating patterns. There were no significant differences in D 2 R availability between obese and nonobese subjects in any brain region. Meta-analysis confirmed that current evidence for altered D 2 R availability in obesity is only modest. Obesity appears to have unique neurobiological underpinnings in the reward circuit, whereby it is more similar to opioid addiction than to other addictive disorders. The opioid system modulates motivation and reward processing, and low -opioid availability may promote overeating to compensate decreased hedonic responses in this system. Behavioral and pharmacological strategies for recovering opioidergic function might thus be critical to curb the obesity epidemic.

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Section: Methodsmentioning

confidence: 99%

Obesity Is Associated with Decreased μ-Opioid But Unaltered Dopamine D₂Receptor Availability in the Brain

et al. 2015

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“…High specific radioactivity [ 11 C]methyl iodide was prepared from [ 11 C]methane. 19,20 The preparation of [ 11 C]raclopride from [ 11 C]methyl triflate was performed according to a published procedure. 21 The radiochemical purity, exceeding 99.5%, and the specific radioactivity of the product were determined using high-performance liquid chromatography and ultraviolet-detection at 214 nm.…”

Section: Preparation Of [ 11 C]raclopridementioning

confidence: 99%

Intravenous Ethanol Increases Dopamine Release in the Ventral Striatum in Humans: PET Study Using Bolus-Plus-Infusion Administration of [¹¹C]raclopride

Aalto

Ingman

Alakurtti

et al. 2015

J Cereb Blood Flow Metab

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Ethanol increases the interstitial dopamine (DA) concentration in the nucleus accumbens (NAcc) of experimental animals, but positron emission tomography (PET) studies using the single-bolus protocol of the [ 11 C]-raclopride competition paradigm have yielded conflicting results in humans. To resolve disparate previous findings, we utilized the bolus-plus-infusion (B/I) method, allowing both baseline and intervention quantification of [ 11 C]raclopride binding during a single 105-minute PET scan, to investigate possible ethanol-induced DA release in nine healthy male subjects. A 25-minute intravenous ethanol (7.6%) infusion, resulting in a 1.3 g/L mean blood ethanol concentration, was administered using masked timing during the PET scan. Automated region-of-interest analysis testing the difference between baseline (40-50 minutes) and intervention (60-85 minutes) revealed an average 12.6% decrease in [ 11 C]raclopride binding in the ventral striatum (VST, P = 0.003) including the NAcc. In addition, a shorter time interval from the start of ethanol infusion to the first subjective effect was associated with a greater binding potential decrease bilaterally in the VST (r = 0.92, P = 0.004), and the feeling of pleasure was associated with a decrease in binding potential values in both the caudate nucleus (r = − 0.87, P = 0.003) and putamen (r = − 0.74; P = 0.02). These results confirm that ethanol induces rapid DA release in the limbic striatum, which can be reliably estimated using the B/I method in one imaging session. Previous PET studies exploring the effects of acute alcohol intervention on DA neurotransmission in humans have yielded conflicting results. The first [ 11 C]raclopride PET study applying oral alcohol administration did not show any effect, 3 but in a later study decreased [ 11 C]raclopride binding was shown, suggesting an increased DA concentration in the VST, although the effect varied considerably among the subjects. 4 Two studies using prolonged stable intravenous ethanol infusion during PET data

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“…High specific radioactivity [ 11 C]methyl iodide was prepared from [ 11 C]methane (Larsen et al 1997 ;Någren et al 2003).…”

Section: Tcimentioning

confidence: 99%

Temperament, character and serotonin activity in the human brain: a positron emission tomography study based on a general population cohort

et al. 2012

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Tuominen, L.; Salo, J.; Hirvonen, J.; Någren, K.; Laine, P.; Melartin, T.; Isometsä, E.; Viikari, J.; Cloninger, C. R.; Raitakari, O.; Hietala, J.; and Keltikangas-Järvinen, L., ,"Temperament, character and serotonin activity in the human brain: A positron emission tomography study based on a general population cohort." Psychological Medicine. 43,4. 881-894. (2012 Background. The psychobiological model of personality by Cloninger and colleagues originally hypothesized that interindividual variability in the temperament dimension ' harm avoidance ' (HA) is explained by differences in the activity of the brain serotonin system. We assessed brain serotonin transporter (5-HTT) density in vivo with positron emission tomography (PET) in healthy individuals with high or low HA scores using an ' oversampling ' study design.Method. Subjects consistently in either upper or lower quartiles for the HA trait were selected from a populationbased cohort in Finland (n=2075) with pre-existing Temperament and Character Inventory (TCI) scores. A total of 22 subjects free of psychiatric and somatic disorders were included in the matched high-and low-HA groups. The main outcome measure was regional 5-HTT binding potential (BP ND ) in high-and low-HA groups estimated with PET and [ 11 C]N,N-dimethyl-2-(2-amino-4-methylphenylthio)benzylamine ([ 11 C]MADAM). In secondary analyses, 5-HTT BP ND was correlated with other TCI dimensions.Results. 5-HTT BP ND did not differ between high-and low-HA groups in the midbrain or any other brain region. This result remained the same even after adjusting for other relevant TCI dimensions. Higher 5-HTT BP ND in the raphe nucleus predicted higher scores in ' self-directedness '.Conclusions. This study does not support an association between the temperament dimension HA and serotonin transporter density in healthy subjects. However, we found a link between high serotonin transporter density and high ' self-directedness ' (ability to adapt and control one's behaviour to fit situations in accord with chosen goals and values). We suggest that biological factors are more important in explaining variability in character than previously thought.

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Synthesis of [11C]iodomethane by iodination of [11C]methane

Cited by 236 publications

References 7 publications

Obesity Is Associated with Decreased μ-Opioid But Unaltered Dopamine D₂Receptor Availability in the Brain

Obesity Is Associated with Decreased μ-Opioid But Unaltered Dopamine D₂Receptor Availability in the Brain

Intravenous Ethanol Increases Dopamine Release in the Ventral Striatum in Humans: PET Study Using Bolus-Plus-Infusion Administration of [¹¹C]raclopride

Temperament, character and serotonin activity in the human brain: a positron emission tomography study based on a general population cohort

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Synthesis of [11C]iodomethane by iodination of [11C]methane

Cited by 236 publications

References 7 publications

Obesity Is Associated with Decreased μ-Opioid But Unaltered Dopamine D2Receptor Availability in the Brain

Obesity Is Associated with Decreased μ-Opioid But Unaltered Dopamine D2Receptor Availability in the Brain

Intravenous Ethanol Increases Dopamine Release in the Ventral Striatum in Humans: PET Study Using Bolus-Plus-Infusion Administration of [11C]raclopride

Temperament, character and serotonin activity in the human brain: a positron emission tomography study based on a general population cohort

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Product

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Obesity Is Associated with Decreased μ-Opioid But Unaltered Dopamine D₂Receptor Availability in the Brain

Obesity Is Associated with Decreased μ-Opioid But Unaltered Dopamine D₂Receptor Availability in the Brain

Intravenous Ethanol Increases Dopamine Release in the Ventral Striatum in Humans: PET Study Using Bolus-Plus-Infusion Administration of [¹¹C]raclopride