+ Site Statistics
+ Search Articles
+ PDF Full Text Service
How our service works
Request PDF Full Text
+ Follow Us
Follow on Facebook
Follow on Twitter
Follow on LinkedIn
+ Subscribe to Site Feeds
Most Shared
PDF Full Text
+ Translate
+ Recently Requested

Influence of pathological concentrations of ammonia on metabolic fate of 14C-labeled glutamate in astrocytes in primary cultures



Influence of pathological concentrations of ammonia on metabolic fate of 14C-labeled glutamate in astrocytes in primary cultures



Journal of Neurochemistry 42(2): 594-597



Rates of glutamine formation and of carbon dioxide production (as an indication of oxidative deamination of glutamate) were determined in primary cultures of astrocytes exposed to 50 microM labeled glutamate in the absence or presence of added ammonia (0.1-3 mM). Glutamine formation (1.7 nmol/min/mg protein) was unaffected by all concentrations of added ammonia. This probably reflects the presence of a low content of ammonia (0.1-0.2 mM), originating from degradation of glutamine, in the cells even in the absence of added ammonia, and it shows that pathophysiological concentrations of ammonia do not increase the formation of glutamine from exogenous glutamate. The carbon dioxide production rate was 5.9 nmol/min/mg protein, i.e., three to four times higher than the rate of glutamine formation. It was significantly reduced (to 3.5 nmol/min/mg protein) in the presence of 1 mM or more of ammonia. This is in keeping with suggestions by others that toxic levels of ammonia affect oxidative metabolism.

Please choose payment method:






(PDF emailed within 0-6 h: $19.90)

Accession: 043401205

Download citation: RISBibTeXText

PMID: 6141224

DOI: 10.1111/j.1471-4159.1984.tb02721.x


Related references

Metabolic fate of 14C-labeled glutamate in astrocytes in primary cultures. Journal of Neurochemistry 39(4): 954-960, 1982

Metabolic fate of [U-14C]-labeled glutamate in primary cultures of mouse astrocytes as a function of development. Developmental Neuroscience 5(2-3): 278-284, 1982

Metabolic Fate of [U- 14 C]-LabeIed Glutamate in Primary Cultures of Mouse Astrocytes as a Function of Development. Developmental Neuroscience 5(2-3): 278-284, 1982

Short term metabolic fate of nitrogen 13 labeled ammonia l nitrogen 13 labeled alanine l nitrogen 13 labeled glutamate and l amide nitrogen 13 labeled glutamine in normal rat liver in vivo. Journal of Hepatology 4(Suppl. 1): S12, 1987

Some metabolic effects of ammonia on astrocytes and neurons in primary cultures. NeurochemicalPathology6(1-2):97, 1987

Effects of chronic exposure to ammonia on glutamate and glutamine interconversion and compartmentation in homogeneous primary cultures of mouse astrocytes. Neurochemical Research. : 257-265, 1994

Metabolic fate of carbon 14 labeled glutamine in mouse cerebral neurons in primary cultures. Journal of Neuroscience Research 11(4): 351-358, 1984

Exogenous glutamate concentration regulates the metabolic fate of glutamate in astrocytes. Journal Of Neurochemistry. 66(1): 386-393, 1996

GFA Content, Glutamate Uptake and Activity of Glutamate Metabolizing Enzymes in Differentiating Mouse Astrocytes in Primary Cultures. Developmental Neuroscience 1(5): 226-238, 1978

The metabolic fate of 13N-labeled ammonia in rat brain. Journal of Biological Chemistry 254(12): 4982-4992, 1979

GABA alters the metabolic fate of [U-13C]glutamate in cultured cortical astrocytes. Journal of Neuroscience Research 79(1-2): 81-87, 2004

The metabolic fate of nitrogen 13 labeled ammonia in rat brain. Journal of Biological Chemistry 254(12): 4982-4-92, 1979

Exogenous glutamate concentration determines metabolic fate of exogenous glutamate in astrocytes. Journal of Neurochemistry 64(Suppl. 1): S66, 1995

Glutamate uptake and glutamate content in primary cultures of mouse astrocytes during anoxia, substrate deprivation and stimulated ischemia under normothermic and hypothermic conditions. Brain Research 618(2): 346-351, 1993

Inhibition of glutamine synthesis induces glutamate dehydrogenase-dependent ammonia fixation into alanine in co-cultures of astrocytes and neurons. Neurochemistry International 59(4): 482-488, 2011