... homoeostasis. GS (glutamine synthetase), which catalyses the ATP-dependent condensation of ammonia and glutamate to form glutamine, is an enzyme particularly found in astrocytes. GS plays a pivotal role in glutamate and glutamine homoeostasis, orchestrating astrocyte glutamate uptake/release and the glutamate...

... hyperpolarized [5- 13 C]glutamine, and treatment-induced tumour cell necrosis can be imaged in vivo from measurements of the conversion of hyperpolarized [1,4- 13 C 2 ]fumarate into malate. Since these substrates are endogenous and, in some cases, have already been safely infused into patients, these techniques...