HPLC Analysis of the Metabolism of 6-[ 18 F]Fluoro-L-DOPA in the Brain of Neonatal Pigs

Vorwieger, Gerd; Brust, Peter; Bergmann, Ralf; Bauer, Reinhard; Walter, Bernd; Füchtner, F.; Steinbach, Jörg; Johannsen, B.

doi:10.1016/b978-012161340-2/50045-7

Cited by 3 publications

(2 citation statements)

References 26 publications

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“…Plasma activity (100 L) was measured in a well counter (COBRA II) cross-calibrated with the tomograph. In addition, nine blood samples (at 2,4,8,12,16,25,50,90, and 120 min) were withdrawn for HPLC analysis to correct the plasma input function for the presence of FDOPA metabolites (26). PET imaging was performed with an ECAT EXACT HRϩ (CTI/Siemens) scanner at a spatial resolution (transaxial) of 4 -5 mm (27).…”

Section: Animalsmentioning

confidence: 99%

Effect of Moderate Hypercapnic Hypoxia on Cerebral Dopaminergic Activity and Brain O2 Uptake in Intrauterine Growth–Restricted Newborn Piglets

et al. 2005

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Section: Animalsmentioning

confidence: 99%

Effect of Moderate Hypercapnic Hypoxia on Cerebral Dopaminergic Activity and Brain O2 Uptake in Intrauterine Growth–Restricted Newborn Piglets

et al. 2005

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“…Plasma activity (100 L) was measured in a well counter (COBRA II) cross-calibrated with the tomograph. Additionally, nine blood samples (at 2, 4, 8, 12, 16, 25, 50, 90, 120 min) were withdrawn for HPLC analysis to correct the plasma input function for the presence of FDOPA metabolites (19).…”

Section: Up-regulation Of Dopamine Synthesis In Iugrmentioning

confidence: 99%

Intrauterine Growth Restriction Induces Up-Regulation of Cerebral Aromatic Amino Acid Decarboxylase Activity in Newborn Piglets: [18F]Fluorodopa Positron Emission Tomographic Study

et al. 2001

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There is evidence that intrauterine growth restriction (IUGR) is associated with altered dopaminergic function in the immature brain. However, the relevant enzyme activities have not been measured in the living neonatal brain together with brain oxidative metabolism. Therefore, fluorine-18-labeled 6-fluoro-L-3,4-dihydroxyphenylalanine (FDOPA) was used together with positron emission tomography to estimate the activity of the aromatic amino acid decarboxylase in the brain of 10 newborn IUGR piglets (2 to 5 d old; body weight, 908 Ϯ 109 g) and in 10 normal-weight (3 to 5 d old; body weight, 2142 Ϯ 373 g) newborn piglets. The regional transport of FDOPA to the brain and the clearance rate of labeled metabolites from brain tissue were broadly similar in the two groups. However, the regional rate constant for back flux from the brain was markedly increased in IUGR piglets for striatum (72%) and frontal cortex (83%) (p Ͻ 0.05). Furthermore, the rate constant for conversion of FDOPA to fluorodopamine was markedly increased (between 48% in cerebellum and 91% in mesencephalon, p Ͻ 0.05) in all brain regions of IUGR piglets studied. Thus, it is suggested that IUGR induces an up-regulation of aromatic amino acid decarboxylase activity that is not related to alterations in brain oxidative metabolism. An inadequate nutritional supply due to uteroplacental insufficiency or restricted maternal protein intake late in gestation is largely responsible for asymmetrical IUGR (1). Reduced fetal growth can be viewed as a compensation for the reduced supply as long as fetal demand is not critically restricted, leading to decompensation with asphyxia and even death (2). The compromised nutritional state has adverse effects on fetal physiology and metabolism including changes of hormonal homeostasis (3), which are thought to be associated with postnatal growth failure and a greater propensity to develop cardiovascular metabolic disease or behavioral abnormalities later in life (4). Therefore, the period of fetal adaptation, characterized by reduced growth due to restricted glucose and amino acid availability but largely compensated placental respiratory function (5), reflects a functional state that may lead to both acceleration or delay in organ maturation (6, 7).The importance of the intrauterine environment for fetal brain development has been stressed by studies showing persistent behavioral abnormalities in prenatally stressed animals (8). Rats exposed to noise and light stress during the last trimester of pregnancy produce offspring with altered locomo- ABSTRACT474

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Metabolite analysis in positron emission tomography studies: examples from food sciences

Pawelke

2005

Amino Acids

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Substances of various chemical structures can be labelled with appropriate positron emitting isotopes and applied as tracer compounds in PET examinations. Using dynamic data acquisition protocols, time-activity curves of radioactivity uptake in organs can be derived and the measurements of tissue tracer concentrations can be translated into quantitative values of tissue function. However, analysis of metabolites of these tracers regarding their nature and distribution in the living organism is an essential need for the quantitative analysis of PET measurements. In addition, metabolite analysis contributes to the interpretation of the images obtained as well as to the identification of pathological changes in metabolic pathways. This paper reports on representative examples of radiolabelled compounds which might be of importance in food science (e.g., amino acids, polyphenols, and model compounds for advanced glycation end products (AGEs)). Typical procedures of analysis (radio-HPLC, radio-TLC) including pre-analytical sample preparation are described. Specific challenges of the method, e.g., trace amounts of radiolabelled compounds and the influence of the often very short half-lives of positron-emitting nuclides used are highlighted. Representative results of analyses of plasma, urine, and tissue samples are presented and discussed in terms of the metabolic fate of the tracers.

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HPLC Analysis of the Metabolism of 6-[ 18 F]Fluoro-L-DOPA in the Brain of Neonatal Pigs

Cited by 3 publications

References 26 publications

Effect of Moderate Hypercapnic Hypoxia on Cerebral Dopaminergic Activity and Brain O2 Uptake in Intrauterine Growth–Restricted Newborn Piglets

Effect of Moderate Hypercapnic Hypoxia on Cerebral Dopaminergic Activity and Brain O2 Uptake in Intrauterine Growth–Restricted Newborn Piglets

Intrauterine Growth Restriction Induces Up-Regulation of Cerebral Aromatic Amino Acid Decarboxylase Activity in Newborn Piglets: [18F]Fluorodopa Positron Emission Tomographic Study

Metabolite analysis in positron emission tomography studies: examples from food sciences

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