Biomaterial Database

Positron Emission Tomography Imaging of Lesions pH Using 11C-Labeled Bicarbonate. 2018

Aixia Sun, and Xiaolan Tang, and Dahong Nie, and Yixiang Fan, and Ganghua Tang

1 Department of Nuclear Medicine and Guangdong Engineering Research Center for Translational Application of Medical Radiopharmaceuticals, The First Affiliated Hospital, SunYat-Sen University , Guangzhou, China .

OBJECTIVE As acid-base imbalance is involved in many pathological processes, the capability to image tissue pH alterations in the clinic could offer new ways to detect disease and respond to treatment. In this study, the authors show that tissue pH can be imaged in vivo with 11C-labeled bicarbonate (H11CO3-) buffer and positron emission tomography (PET). METHODS H11CO3- was produced by on-column NaOH adsorption. Biodistribution of H11CO3- in normal mice was determined. In addition, uptake studies and inhibition experiments of H11CO3- in the S180 fibrosarcoma-bearing mice and the inflammatory mice were investigated with PET imaging. The tumor and inflammatory interstitial pH was measured by a needle pH microelectrode. RESULTS PET imaging demonstrated the high uptake of H11CO3- in mice tumor tissues and inflammatory tissues, which showed that the average tumor or inflammatory interstitial pH was significantly lower than the surrounding tissue. Administration of sodium bicarbonate in the drinking water increased the measured tumor pH, while the uptake of H11CO3- in mice model tissues had no change. Similarly, administration with ammonium chloride (NH4Cl) decreased the pH, whereas the unchanged uptake of H11CO3- in mice model tissues was also found. However, after administration of acetazolamide, the low uptake of H11CO3- in mice model tissues was observed. CONCLUSIONS H11CO3- solution is an endogenous bicarbonate buffer tracer that can be injected into patients without toxicity. H11CO3- PET can be used clinically to image pathological processes that are associated with acid-base imbalance, such as cancer and inflammation.

UI	MeSH Term	Description	Entries
D007249	Inflammation	A pathological process characterized by injury or destruction of tissues caused by a variety of cytologic and chemical reactions. It is usually manifested by typical signs of pain, heat, redness, swelling, and loss of function.	Innate Inflammatory Response,Inflammations,Inflammatory Response, Innate,Innate Inflammatory Responses
D002250	Carbon Radioisotopes	Unstable isotopes of carbon that decay or disintegrate emitting radiation. C atoms with atomic weights 10, 11, and 14-16 are radioactive carbon isotopes.	Radioisotopes, Carbon
D002257	Carbonic Anhydrase Inhibitors	A class of compounds that reduces the secretion of H+ ions by the proximal kidney tubule through inhibition of CARBONIC ANHYDRASES.	Carbonate Dehydratase Inhibitor,Carbonate Dehydratase Inhibitors,Carbonic Anhydrase Inhibitor,Carboxyanhydrase Inhibitor,Carboxyanhydrase Inhibitors,Anhydrase Inhibitor, Carbonic,Dehydratase Inhibitor, Carbonate,Inhibitor, Carbonate Dehydratase,Inhibitor, Carbonic Anhydrase,Inhibitor, Carboxyanhydrase,Inhibitors, Carbonate Dehydratase,Inhibitors, Carbonic Anhydrase,Inhibitors, Carboxyanhydrase
D004195	Disease Models, Animal	Naturally-occurring or experimentally-induced animal diseases with pathological processes analogous to human diseases.	Animal Disease Model,Animal Disease Models,Disease Model, Animal
D005354	Fibrosarcoma	A sarcoma derived from deep fibrous tissue, characterized by bundles of immature proliferating fibroblasts with variable collagen formation, which tends to invade locally and metastasize by the bloodstream. (Stedman, 25th ed)	Fibrosarcomas
D006801	Humans	Members of the species Homo sapiens.	Homo sapiens,Man (Taxonomy),Human,Man, Modern,Modern Man
D006863	Hydrogen-Ion Concentration	The normality of a solution with respect to HYDROGEN ions; H+. It is related to acidity measurements in most cases by pH	pH,Concentration, Hydrogen-Ion,Concentrations, Hydrogen-Ion,Hydrogen Ion Concentration,Hydrogen-Ion Concentrations
D000086	Acetazolamide	One of the CARBONIC ANHYDRASE INHIBITORS that is sometimes effective against absence seizures. It is sometimes useful also as an adjunct in the treatment of tonic-clonic, myoclonic, and atonic seizures, particularly in women whose seizures occur or are exacerbated at specific times in the menstrual cycle. However, its usefulness is transient often because of rapid development of tolerance. Its antiepileptic effect may be due to its inhibitory effect on brain carbonic anhydrase, which leads to an increased transneuronal chloride gradient, increased chloride current, and increased inhibition. (From Smith and Reynard, Textbook of Pharmacology, 1991, p337)	Acetadiazol,Acetazolam,Acetazolamide Sodium, (Sterile),Acetazolamide, Monosodium Salt,Ak-Zol,Apo-Acetazolamide,Diacarb,Diamox,Diuramide,Défiltran,Edemox,Glauconox,Glaupax,Huma-Zolamide,Ak Zol,AkZol,Apo Acetazolamide,ApoAcetazolamide,Huma Zolamide,HumaZolamide
D000818	Animals	Unicellular or multicellular, heterotrophic organisms, that have sensation and the power of voluntary movement. Under the older five kingdom paradigm, Animalia was one of the kingdoms. Under the modern three domain model, Animalia represents one of the many groups in the domain EUKARYOTA.	Animal,Metazoa,Animalia
D001639	Bicarbonates	Inorganic salts that contain the -HCO3 radical. They are an important factor in determining the pH of the blood and the concentration of bicarbonate ions is regulated by the kidney. Levels in the blood are an index of the alkali reserve or buffering capacity.	Bicarbonate,Bicarbonate Ions,Hydrogen Carbonates,Bicarbonate Ion,Carbonic Acid Ions,Hydrogen Carbonate,Carbonate, Hydrogen,Carbonates, Hydrogen,Ion, Bicarbonate,Ions, Bicarbonate,Ions, Carbonic Acid