Amino acid uptake, protein and nucleic acid synthesis and turnover in Bacillus stearothermophilus

1966 ◽  
Vol 123 (2) ◽  
pp. 364-375 ◽  
Author(s):  
B. Bubela ◽  
E.S. Holdsworth
Keyword(s):  
Amino Acid ◽  
Nucleic Acid ◽  
Bacillus Stearothermophilus ◽  
Amino Acid Uptake ◽  
Acid Synthesis ◽  
Nucleic Acid Synthesis ◽  
Acid Uptake

scholarly journals Macrophage metabolism in the intestine is compartment-specific and regulated by the microbiota

2021 ◽  
Author(s):  
Nicholas A Scott ◽  
Melissa Lawson ◽  
Ryan Hodgetts ◽  
Lindsay J Hall ◽  
Elizabeth Mann
Keyword(s):  
Fatty Acid ◽  
Amino Acid ◽  
Amino Acid Uptake ◽  
Acid Synthesis ◽  
Fatty Acid Uptake ◽  
Vital Role ◽  
Antibiotic Administration ◽  
Acid Uptake ◽  
Large Neutral Amino Acid ◽  
Metabolic Functions

Intestinal macrophages play a vital role in the maintenance of gut homeostasis through signals derived from the microbiota. We previously demonstrated that microbial-derived metabolites can shape the metabolic functions of macrophages. Here, we show that antibiotic-induced disruption of the intestinal microbiota dramatically alters both the local metabolite environment, and the metabolic functions of macrophages in the colon. Broad-spectrum antibiotic administration in mice increased expression of the large neutral amino acid transporter and accordingly, amino acid uptake. Subsequently, antibiotic administration enhanced the metabolic functions of colonic macrophages, increasing phosphorylation of components of mammalian/mechanistic target of rapamycin (mTOR) signalling pathways, increasing expression of genes involved in glycolysis and oxidative phosphorylation (OXPHOS), increasing mitochondrial function and increased levels of ECAR and OCR as a direct measure of glycolysis and OXPHOS. Small bowel macrophages were less metabolically active than in the colon, with macrophage metabolism being independent of the microbiota. Finally, we reveal tissue resident Tim4+ CD4+ macrophages exhibit enhanced fatty acid uptake alongside reduced fatty acid synthesis compared to their recruited counterparts. Thus the microbiota shapes gut macrophage metabolism in a compartment-specific manner, with important implications for functions when monocyte recruitment and macrophage differentiation.

scholarly journals Effect of IGF-I on serine metabolism in fetal sheep

2000 ◽  
Vol 165 (2) ◽  
pp. 261-269 ◽  
Author(s):  
EC Jensen ◽  
P van Zijl ◽  
PC Evans ◽  
JE Harding
Keyword(s):  
Amino Acid ◽  
Amino Acid Metabolism ◽  
Acid Metabolism ◽  
Amino Acid Uptake ◽  
Acid Synthesis ◽  
Acid Oxidation ◽  
Acid Uptake ◽  
Amino Acid Synthesis ◽  
Fetal Sheep ◽  
Igf I

Acute infusion of IGF-I to the fetus has been shown to inhibit amino acid oxidation and appears to increase fetoplacental amino acid uptake. This study was designed to investigate further the effects of IGF-I on fetal amino acid metabolism. Radiolabeled serine was used to test the hypothesis that fetal IGF-I infusion enhances serine uptake into the fetus and/or placenta and inhibits serine oxidation. Eight fetal sheep were studied at 127 days of gestation before and during a 4-h infusion of IGF-I (50 microg/h per kg). During the infusion there was no change in uptake of serine or its oxidation by fetus or placenta. However, both uptake and oxidation of serine and glycine decreased in the fetal carcass. There was also a decrease in fetal blood serine and glycine concentrations which could indicate a decrease in protein breakdown, although reduced amino acid synthesis cannot be excluded. Thus IGF-I appeared to influence the distribution of these amino acids as oxidative substrates between different fetal tissues. In addition, fetal IGF-I infusion increased the conversion of serine to glycine which is likely to have increased the availability of one-carbon groups for biosynthesis. Our data provide further evidence that IGF-I plays a role in the regulation of fetoplacental amino acid metabolism.

scholarly journals Molecular Imaging of Brain Tumor-Associated Epilepsy

Diagnostics ◽  
2020 ◽  
Vol 10 (12) ◽  
pp. 1049
Author(s):  
Csaba Juhász ◽  
Sandeep Mittal
Keyword(s):  
Brain Tumor ◽  
Amino Acid ◽  
Brain Tumors ◽  
Treatment Strategies ◽  
Amino Acid Uptake ◽  
Seizure Outcome ◽  
Acid Uptake ◽  
Positron Emission ◽  
Oncology Practice ◽  
Glioneuronal Tumors

Epilepsy is a common clinical manifestation and a source of significant morbidity in patients with brain tumors. Neuroimaging has a pivotal role in neuro-oncology practice, including tumor detection, differentiation, grading, treatment guidance, and posttreatment monitoring. In this review, we highlight studies demonstrating that imaging can also provide information about brain tumor-associated epileptogenicity and assist delineation of the peritumoral epileptic cortex to optimize postsurgical seizure outcome. Most studies focused on gliomas and glioneuronal tumors where positron emission tomography (PET) and advanced magnetic resonance imaging (MRI) techniques can detect metabolic and biochemical changes associated with altered amino acid transport and metabolism, neuroinflammation, and neurotransmitter abnormalities in and around epileptogenic tumors. PET imaging of amino acid uptake and metabolism as well as activated microglia can detect interictal or peri-ictal cortical increased uptake (as compared to non-epileptic cortex) associated with tumor-associated epilepsy. Metabolic tumor volumes may predict seizure outcome based on objective treatment response during glioma chemotherapy. Advanced MRI, especially glutamate imaging, can detect neurotransmitter changes around epileptogenic brain tumors. Recently, developed PET radiotracers targeting specific glutamate receptor types may also identify therapeutic targets for pharmacologic seizure control. Further studies with advanced multimodal imaging approaches may facilitate development of precision treatment strategies to control brain tumor-associated epilepsy.

Sign in / Sign up

Export Citation Format

Share Document