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- Dubol, Manon, et al.
(författare)
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Acute nicotine exposure blocks aromatase in the limbic brain of healthy women : A [11C]cetrozole PET study
- 2023
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Ingår i: Comprehensive Psychiatry. - : Elsevier. - 0010-440X .- 1532-8384. ; 123
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Tidskriftsartikel (refereegranskat)abstract
- Background: Of interest to women's mental health, a wealth of studies suggests sex differences in nicotine addiction and treatment response, but their psychoneuroendocrine underpinnings remain largely unknown. A pathway involving sex steroids could indeed be involved in the behavioural effects of nicotine, as it was found to inhibit aromatase in vitro and in vivo in rodents and non-human primates, respectively. Aromatase regulates the synthesis of oestrogens and, of relevance to addiction, is highly expressed in the limbic brain.Methods: The present study sought to investigate in vivo aromatase availability in relation to exposure to nicotine in healthy women. Structural magnetic resonance imaging and two [11C]cetrozole positron emission tomography (PET) scans were performed to assess the availability of aromatase before and after administration of nicotine. Gonadal hormones and cotinine levels were measured. Given the region-specific expression of aromatase, a ROI -based approach was employed to assess changes in [11C]cetrozole non-displaceable binding potential.Results: The highest availability of aromatase was found in the right and left thalamus. Upon nicotine exposure, [11C]cetrozole binding in the thalamus was acutely decreased bilaterally (Cohen's d =-0.99). In line, cotinine levels were negatively associated with aromatase availability in the thalamus, although as non-significant trend.Conclusions: These findings indicate acute blocking of aromatase availability by nicotine in the thalamic area. This suggests a new putative mechanism mediating the effects of nicotine on human behaviour, particularly relevant to sex differences in nicotine addiction.
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| 2. |
- Jonasson, My, et al.
(författare)
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Quantification of aromatase binding in the female human brain using [11 C]cetrozole positron emission tomography.
- 2020
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Ingår i: Journal of Neuroscience Research. - : Wiley. - 0360-4012 .- 1097-4547. ; 98:11, s. 2208-2218
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Tidskriftsartikel (refereegranskat)abstract
- Aromatase, the enzyme that in the brain converts testosterone and androstenedione to estradiol and estrone, respectively, is a putative key factor in psychoneuroendocrinology. In vivo assessment of aromatase was performed to evaluate tracer kinetic models and optimal scan duration, for quantitative analysis of the aromatase positron emission tomography (PET) ligand [11 C]cetrozole. Anatomical magnetic resonance and 90-min dynamic [11 C]cetrozole PET-CT scans were performed on healthy women. Volume of interest (VOI)-based analyses with a plasma-input function were performed using the single-tissue and two-tissue (2TCM) reversible compartment models and plasma-input Logan analysis. Additionally, the simplified reference tissue model (SRTM), Logan reference tissue model (LRTM), and standardized uptake volume ratio model, with cerebellum as reference region, were evaluated. Parametric images were generated and regionally averaged voxel values were compared with VOI-based analyses of the reference tissue models. The optimal reference model was used for evaluation of a decreased scan duration. Differences between the plasma-input- and reference tissue-based methods and comparisons between scan durations were assessed by linear regression. The [11 C]cetrozole time-activity curves were best described by the 2TCM. SRTM nondisplaceable binding potential (BPND ), with cerebellum as reference region, can be used to estimate [11 C]cetrozole binding and generated robust and quantitatively accurate results for a reduced scan duration of 60 min. Receptor parametric mapping, a basis function implementation of SRTM, as well as LRTM, produced quantitatively accurate parametric images, showing BPND at the voxel level. As PET tracer, [11 C]cetrozole can be employed for relatively short brain scans to measure aromatase binding using a reference tissue-based approach.
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| 6. |
- Takahashi, Kayo, et al.
(författare)
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Increase in hypothalamic aromatase in macaque monkeys treated with anabolic-androgenic steroids : PET study with [C-11]vorozole
- 2011
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Ingår i: NeuroReport. - 0959-4965 .- 1473-558X. ; 22:7, s. 326-330
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Tidskriftsartikel (refereegranskat)abstract
- In an earlier study in rodents, we showed that the aromatase that converts androgens to estrogens in the preoptic area and bed nucleus of stria terminalis was significantly increased in concentration after exposure to anabolic-androgenic steroids. To confirm whether this occurs in primates, we conducted a positron emission tomographic study using macaque monkeys. Male rhesus monkeys were treated with nandrolone decanoate for 3 weeks. To measure aromatase concentrations, we performed positron emission tomographic imaging using a C-11-labeled specific aromatase inhibitor, [C-11] vorozole. After treatment with nandrolone, significant increase in [C-11] vorozole binding was observed in the hypothalamus but not other areas including the amygdala, which is also aromatase enriched. These findings in monkeys are consistent with those we obtained earlier in rats. These findings strongly suggest that aromatase in the hypothalamus may play a crucial role in the emotional instability of anabolic-androgenic steroids abusers. NeuroReport 22:326-330 (C) 2011 Wolters Kluwer Health vertical bar Lippincott Williams & Wilkins.
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