Regional brain monoamines and their metabolites after portacaval shunting

Am, Mans; Mw, Consevage; Mr, DeJoseph; Hawkins, R. A.

doi:10.1007/bf00999609

Cited by 16 publications

(4 citation statements)

References 31 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…In the present investigation, increased brain levels of 5-HTP and 5-HIAA with no changes in 5-HT content in the brain were observed after PCA (Table 2), in agreement with previous reports Mans et al, 1987;Bugge et al, 1988). Following NH4Ac injection to PCA rats, 5-HTP and 5-HT concentrations remained unchanged whereas 5-HIAA levels were found to be elevated in precoma shunted rats (PCA-P) compared to shunted rats (PCA) with no further changes with impending coma (PCA-C).…”

Section: Discussionsupporting

confidence: 94%

Effect of Ammonia on Brain Serotonin Metabolism in Relation to Function in the Portacaval Shunted Rat

Bergeron

Swain

Reader

et al. 1990

Journal of Neurochemistry

View full text Add to dashboard Cite

Four weeks following portacaval anastomosis (PCA) in the rat, severe liver atrophy, sustained hyperammonemia, and increased plasma and brain tryptophan are observed. Administration of ammonium acetate (NH4Ac) to rats with PCA precipitates severe signs of hepatic encephalopathy (HE) (loss of righting reflex progressing to loss of consciousness and ultimately deep coma). To evaluate the relationship between the deterioration of neurological status in HE and serotonin (5-HT) metabolism, the levels of 5-HT, its precursor 5-hydroxytryptophan, and its major metabolite 5-hydroxy-indole-3-acetic acid (5-HIAA) were measured by HPLC with ion-pairing and electrochemical detection in three well-defined areas of the cerebral cortex: anterior cingulate, piriform and entorhinal, and frontoparietal; as well as in the caudate-putamen, the raphe nuclei, and the locus ceruleus in rats with PCA at different stages of HE, before and after injection of NH4Ac, as well as in sham-operated controls. The results demonstrate increased 5-HIAA/5-HT ratios after PCA and NH4Ac loading, suggesting increased 5-HT turnover in the brains of these animals. However, these changes do not appear to be related to the precipitation of coma as no significant difference in 5-HT turnover was observed between precoma and coma stages of HE. Increased 5-HT turnover in brain of shunted rats may be related to early symptoms of HE such as altered sleep patterns and disorders of motor coordination.

show abstract

Section: Discussionsupporting

confidence: 94%

Effect of Ammonia on Brain Serotonin Metabolism in Relation to Function in the Portacaval Shunted Rat

Bergeron

Swain

Reader

et al. 1990

Journal of Neurochemistry

View full text Add to dashboard Cite

show abstract

“…Similar results were also obtained by Bhetii and Chang (6,14), who additionally analyzed the release of the substance P responsible for the release of dopamine in the caudate nucleus (36). As in the case of noradrenaline, there are publications that do not confirm the increase in dopamine levels during AP (5,8,42). Undoubtedly, comorbidities (sepsis, pulmonary inflammation, brain edema) cause changes in the level of neurotransmitters that affect the biochemical response of the body, including hypoxia, which was confirmed by the present experiment.…”

Section: Resultssupporting

confidence: 70%

“…This was confirmed by Baraldi,Hadesman and McKinzie (5,27,45) in their studies on damaged livers. On the other hand, Mans and Simert (42,55) showed opposite changes, which did not confirm reduction in the values analyzed. 19) conducted a similar experiment in humans with liver failure and advanced encephalopathy.…”

Section: Resultsmentioning

confidence: 60%

Changes in noradrenaline and dopamine levels under oxygen debt conditions in the brain of rats during experimental acute pancreatitis

Markiewicz-Gospodarek¹,

Łuszczewska-Sierakowska²,

Kuszta³

et al. 2022

Medycyna Weterynaryjna

View full text Add to dashboard Cite

This study’s aim was to assess the level of catecholamines, i.e., noradrenaline and dopamine, under oxygen debt conditions in the brain of experimental animals in which acute pancreatitis was experimentally induced. Catecholamines play the role of neurotransmitters and neuromediators. They are responsible for the regulation of motor and emotional processes, take part in the regulation of hormonal activities, sleep, wakefulness, concentration, attention, and learning processes. The experiment also determined the oxygen tension as an indicator of respiratory failure and the activity of amylase and lipase in the development of the inflammatory process. The animals on which the experiment was conducted were Wistar rats (140 animals) divided into 3 research groups: control (C) animals (n = 30), healthy (H) animals (n = 30), and operated (O) animals (n = 80). The determination of amylase, lipase, oxygen pressure, NA, and DO levels were performed at hours 2, 6, 12, 24, and 48 of the experiment. The animals in group C had an injection needle inserted to investigate only the effects of mechanical damage to the organs. On the other hand, the animals in group O had a 5% solution of sodium taurocholate introduced into the common bile-pancreatic duct. The research conducted shows that the most significant changes in NA and DO levels were observed on the first day of the experiment. The concentrations of the above catecholamines were statistically significantly correlated with the level of amylase in the blood. The peak of dopamine was observed between the 6th and 12th hours of the experiment, while the lowest concentration of noradrenaline was observed at the 6th hour of the experiment.

show abstract

“…The brain samples were extracted in HC104 containing 2 % cysteine and were assayed on the same day. The conditions were as described by Mans et al (1987), except that the pH of the mobile phase was 4.5. Plasma ammonia, brain glutamine and all the other metabolites were assayed enzymically (Bergmeyer, 1974).…”

Section: Assays and Tissue Samplesmentioning

confidence: 99%

Hyperammonaemia causes many of the changes found after portacaval shunting

Jessy

Mans

DeJoseph

et al. 1990

Biochemical Journal

View full text Add to dashboard Cite

1. Portacaval shunting in rats results in several metabolic alterations similar to those seen in patients with hepatic encephalopathy. The characteristic changes include: (a) diminution of cerebral function; (b) raised plasma ammonia and brain glutamine levels; (c) increased neutral amino acid transport across the blood-brain barrier; (d) altered brain and plasma amino acid levels; and (e) changes in brain neurotransmitter content. The aetiology of these abnormalities remains unknown. 2. To study the degree to which ammonia could be responsible, rats were made hyperammonaemic by administering 40 units of urease/kg body weight every 12 h and killing the rats 48 h after the first injection. 3. The changes observed in the urease-treated rats were: (a) whole-brain glucose use was significantly depressed, whereas the levels of high-energy phosphates remained unchanged; (b) the permeability of the blood-brain to barrier to two large neutral amino acids, tryptophan and leucine, was increased; (c) blood-brain barrier integrity was maintained, as indicated by the unchanged permeability-to-surface-area product for acetate; (d) plasma and brain amino acid concentrations were altered; and (e) dopamine, 5-hydroxytryptamine (serotonin) and noradrenaline levels in brain were unchanged, but 5-hydroxyindoleacetic acid (5-HIAA), a metabolite of 5-hydroxytryptamine, was elevated. 4. The depressed brain glucose use, increased tryptophan permeability-to-surface-area product, elevated brain tryptophan content and rise in the level of cerebral 5-HIAA were closely correlated with the observed rise in brain glutamine content. 5. These results suggest that many of the metabolic alterations seen in rats with portacaval shunts could be due to elevated ammonia levels. Furthermore, the synthesis or accumulation of glutamine may be closely linked to cerebral dysfunction in hyperammonaemia.

show abstract

Regional brain monoamines and their metabolites after portacaval shunting

Cited by 16 publications

References 31 publications

Effect of Ammonia on Brain Serotonin Metabolism in Relation to Function in the Portacaval Shunted Rat

Effect of Ammonia on Brain Serotonin Metabolism in Relation to Function in the Portacaval Shunted Rat

Changes in noradrenaline and dopamine levels under oxygen debt conditions in the brain of rats during experimental acute pancreatitis

Hyperammonaemia causes many of the changes found after portacaval shunting

Contact Info

Product

Resources

About