5-Oxoproline reduces non-enzymatic antioxidant defenses in vitro in rat brain.

5-Oxoproline (pyroglutamic acid) accumulates in glutathione synthetase deficiency, an inborn metabolic defect of the gamma-glutamyl cycle. This disorder is clinically characterized by hemolytic anemia, metabolic acidosis and severe neurological disorders. Considering that the mechanisms of brain damage in this disease are poorly known, in the present study we investigated whether oxidative stress is elicited by 5-oxoproline.

Gamma-hydroxybutyric acid induces oxidative stress in cerebral cortex of young rats.

GHB is a naturally occurring compound in the central nervous system (CNS) whose tissue concentration are highly increased during drug abuse and in the inherited deficiency of succinic semialdehyde dehydrogenase (SSADH) activity. SSADH deficiency is a neurometabolic-inherited disorder of the degradation pathway of gamma-aminobutyric acid (GABA). It is biochemically characterized by increased concentrations of gamma-hydroxybutyric acid (GHB) in tissues, cerebrospinal fluid (CSF), blood and urine of affected patients.

Citrulline and ammonia accumulating in citrullinemia reduces antioxidant capacity of rat brain in vitro.

Citrullinemia is an inborn error of the urea cycle caused by deficient argininosuccinate synthetase, which leads to accumulation of L-citrulline and ammonia in tissues and body fluids. The main symptoms include convulsions, tremor, seizures, coma, and brain edema. The pathophysiology of the neurological signs of citrullinemia remains unclear.

Astrocyte stellation in saline media lacking bicarbonate: possible relation to intracellular pH and tyrosine phosphorylation.

Primary cultures of astrocytes exhibit a polygonal morphology, but on treatment with agents that increase cAMP they change to stellate cells. We found that astrocyte stellation also occurred on replacing the culture medium with saline buffered with HEPES. However, stellation did not occur when the medium was replaced with saline buffered with bicarbonate/CO(2) provided Ca(2+) was present.