TY - JOUR
T1 - Differential Distribution of Purine Metabolizing Enzymes Between Glia and Neurons
AU - Ceballos, Guillermo
AU - Tuttle, Jeremy B.
AU - Rubio, Rafael
PY - 1994/3
Y1 - 1994/3
N2 - Abstract: Previous studies showed that in cultured chick ciliary ganglion neurons and CNS glia, adenosine can be synthesized by hydrolysis of 5′‐AMP and that the accumulation of the adenosine degradative products inosine and hypoxanthine was significantly greater in glial than in neuronal cultures. Furthermore, previous immunochemical and histochemical studies in brain showed that adenosine deaminase and nucleoside phosphorylase are localized in endothelial and glial cells but are absent in neurons; however, adenosine deaminase may be found in a few neurons in discrete brain regions. These results suggested that adenosine degradative pathways may be more active in glia. Thus, we have determined if there is a differential distribution of adenosine deaminase, nucleoside phosphorylase, and xanthlne oxidase enzyme fluxes in glia, comparing primary cultures of central and ciliary ganglion neurons and glial cells from chick embryos. Hypoxanthine‐guanine phosphoribosyltransferase and production of adenosine by S‐adenosylhomocysteine hydrolase activity were also examined. Our results show that there is a distinct profile of purine metabolizing enzymes for glia and neurons in culture. Both cell types have an S‐adenosylhomocysteine hydrolase, but it was more active in neurons than in glia. In contrast, in glia the enzymatic activities of xanthine oxidase (443 ± 61 pmol/min/107 cells), nucleoside phosphorylase (187 ± B pmol/min/107 cells), and adenosine deaminase (233 ± 32 pmol/min/107 cells) were more active at least 100, 20, and five times, respectively, than in ciliary ganglion neurons and 100, 100, and nine times, respectively, than in central neurons.
AB - Abstract: Previous studies showed that in cultured chick ciliary ganglion neurons and CNS glia, adenosine can be synthesized by hydrolysis of 5′‐AMP and that the accumulation of the adenosine degradative products inosine and hypoxanthine was significantly greater in glial than in neuronal cultures. Furthermore, previous immunochemical and histochemical studies in brain showed that adenosine deaminase and nucleoside phosphorylase are localized in endothelial and glial cells but are absent in neurons; however, adenosine deaminase may be found in a few neurons in discrete brain regions. These results suggested that adenosine degradative pathways may be more active in glia. Thus, we have determined if there is a differential distribution of adenosine deaminase, nucleoside phosphorylase, and xanthlne oxidase enzyme fluxes in glia, comparing primary cultures of central and ciliary ganglion neurons and glial cells from chick embryos. Hypoxanthine‐guanine phosphoribosyltransferase and production of adenosine by S‐adenosylhomocysteine hydrolase activity were also examined. Our results show that there is a distinct profile of purine metabolizing enzymes for glia and neurons in culture. Both cell types have an S‐adenosylhomocysteine hydrolase, but it was more active in neurons than in glia. In contrast, in glia the enzymatic activities of xanthine oxidase (443 ± 61 pmol/min/107 cells), nucleoside phosphorylase (187 ± B pmol/min/107 cells), and adenosine deaminase (233 ± 32 pmol/min/107 cells) were more active at least 100, 20, and five times, respectively, than in ciliary ganglion neurons and 100, 100, and nine times, respectively, than in central neurons.
KW - Adenosine deaminase
KW - Embryonic cells
KW - Hypoxanthine‐guanine phosphoribosyltransferase
KW - Purine nucleoside phosphorylase
KW - S‐Adenosylhomocysteine hydrolase
KW - Xanthine oxidase
UR - http://www.scopus.com/inward/record.url?scp=0028157339&partnerID=8YFLogxK
U2 - 10.1046/j.1471-4159.1994.62031144.x
DO - 10.1046/j.1471-4159.1994.62031144.x
M3 - Artículo
SN - 0022-3042
VL - 62
SP - 1144
EP - 1153
JO - Journal of Neurochemistry
JF - Journal of Neurochemistry
IS - 3
ER -