MRI using hyperpolarized (13) C-labeled pyruvate is a promising tool to biochemically profile tumors and monitor their response to therapy. This technique requires injection of pyruvate into tumor-bearing animals. Pyruvate is an endogenous entity but the influence of exogenously injected bolus doses of pyruvate on tumor microenvironment is not well understood. In this study, the effect of injecting a bolus of pyruvate on tumor oxygen status was investigated. EPR oxygen imaging revealed that the partial pressure of oxygen (pO(2)) in squamous cell carcinoma implanted in mice decreased significantly 30 min after [1-(13) C]pyruvate injection, but recovered to preinjection levels after 5 h. Dynamic contrast-enhanced-MRI studies showed that, at the dose of pyruvate used, no changes in tumor perfusion were noticed. Immunohistochemical analysis of hypoxic marker pimonidazole independently verified that the squamous cell carcinoma tumor transiently became more hypoxic by pyruvate injection. Efficacy of radiotherapy was suppressed when X-irradiation was delivered during the period of pyruvate-induced transient hypoxia. These results suggest importance of taking into account the transient decrease in tumor pO(2) after pyruvate injection in hyperpolarized (13) C MRI, because tumor oxygen status is an important factor in determining outcomes of therapies.

Download full-text PDF

Source
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3262125PMC
http://dx.doi.org/10.1002/mrm.23065DOI Listing

Publication Analysis

Top Keywords

pyruvate
9
transient decrease
8
decrease tumor
8
pyruvate tumor
8
tumor oxygen
8
oxygen status
8
squamous cell
8
cell carcinoma
8
pyruvate injection
8
tumor
7

Similar Publications

Microalgal-based urea wastewater treatment with p-Hydroxybenzoic acid enhances resource recovery and mitigates biological risks from Bisphenol A.

Water Res

January 2025

Key Laboratory of Groundwater Resources and Environment (Jilin University), Ministry of Education, Jilin University, Changchun 130021, Jilin, PR China; Chongqing Research Institute, Jilin University, 401120 Chongqing, PR China; Jilin Provincial Key Laboratory of Water Resources and Environment, Jilin University, Changchun 130021, Jilin, PR China. Electronic address:

Efficient nutrient recovery from source-separated urine is vital for wastewater treatment, with microalgae as a promising solution. However, bisphenol A (BPA) in urine can hinder microalgal resource recovery and pose water quality risks. The role of plant hormones in enhancing microalgal growth and pollutant removal is known, but their impact on BPA-laden urine treatment is not well-studied.

View Article and Find Full Text PDF

Nonalcoholic fatty liver disease (NAFLD) is one of the main causes of chronic liver disorders following liver transplantation. The prorenin receptor (PRR) plays a role in glucose and lipid metabolism, and the hepatic dysregulation of PRR is associated with the upregulation of several molecular pathways, such as the mammalian target of rapamycin (mTOR) and Peroxisome proliferator-activated receptor (PPAR) that promotes hepatic lipogenesis and leads to lipid accumulation in hepatocytes by upregulation of lipogenic genes. PRR inhibition leads to a reduction in the hepatic expression of sortilin-1 and low-density lipoprotein receptor (LDLR) levels and down-regulation of pyruvate dehydrogenase (PDH) and acetyl-CoA carboxylase (ACC) and reduces fatty acids synthesis in hepatocytes.

View Article and Find Full Text PDF

ATP Regeneration from Pyruvate in the PURE System.

ACS Synth Biol

January 2025

Centre for Engineering Biology, Institute of Quantitative Biology, Biochemistry and Biotechnology, School of Biological Sciences, University of Edinburgh, Edinburgh EH9 3FF, U.K.

The "Protein synthesis Using Recombinant Elements" ("PURE") system is a minimal biochemical system capable of carrying out cell-free protein synthesis using defined enzymatic components. This study extends PURE by integrating an ATP regeneration system based on pyruvate oxidase, acetate kinase, and catalase. The new pathway generates acetyl phosphate from pyruvate, phosphate, and oxygen, which is used to rephosphorylate ATP .

View Article and Find Full Text PDF

Pivotal role of exogenous pyruvate in human natural killer cell metabolism.

Nat Metab

January 2025

CIRI, Centre International de Recherche en Infectiologie, (Team Lyacts), Univ Lyon, INSERM, U1111, Université Claude Bernard Lyon 1, CNRS, UMR5308, ENS de Lyon, Lyon, France.

Resting natural killer (NK) cells display immediate effector functions after recognizing transformed or infected cells. The environmental nutrients and metabolic requirements to sustain these functions are not fully understood. Here, we show that NK cells rely on the use of extracellular pyruvate to support effector functions, signal transduction and cell viability.

View Article and Find Full Text PDF

Natural killer loops: pyruvate in, lactate out.

Nat Metab

January 2025

School of Biochemistry and Immunology, Trinity Biomedical Sciences Institute, Trinity College Dublin, Dublin, Ireland.

View Article and Find Full Text PDF

Want AI Summaries of new PubMed Abstracts delivered to your In-box?

Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!