Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:3.1.4.37 (CNPase)
 539 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Neuron-glia cocultures were prepared using, as a source for glial cells, either C6 glia (2B clone) of early (2B23) or late (2B111) passages or advanced passages of glial cells derived from primary cultures prepared from aged mouse cerebral hemispheres (MACH). Six-day-old chick embryo cerebral hemispheres (E6CH) were the source of neuron-enriched cultures. Glutamine synthetase (GS) activity was used as a marker for astrocytes and 2',3'-cyclic nucleotide 3'-phosphohydrolase (CNP) activity was used as a marker for oligodendrocytes. GS activity was markedly enhanced in cocultures of E6CH neurons and 2B23 glioblastic cells, whereas GS activity was reduced in cocultures of E6CH neurons and 2B111 astrocytic glia. In contrast, CNP activity was enhanced in cocultures of C6 glial cells with E6CH neurons. Glial cells from aged mouse brain did not respond to coculturing with E6CH neurons. It appears from these findings that neuronal input enhances the differentiation of glioblastic cells to either astrocytic or oligodendrocytic expression, whereas it decreases the activity of committed astrocytes. In contrast, glial cells from aged mouse brain do not respond to neuronal input. Choline acetyltransferase (ChAT) activity, a marker for cholinergic neurons, was enhanced only when E6CH cultures were grown in conditioned medium (CM) from 2B23 glioblastic cells. In contrast, ChAT activity was markedly diminished when E6CH neurons were cocultured with MACH glial cells but not when grown in CM from MACH glial cells. Thus, humoral factors from immature glial cells appear to enhance cholinergic neuronal phenotypic expression whereas cell-cell membrane contacts with aged glial cells diminish cholinergic phenotypic expression. The findings present supportive evidence that neuron-glia interrelationships are age dependent.
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PMID:Differences in neuronal and glial cell phenotypic expression in neuron-glia cocultures: influence of glia-conditioned media and living glial cell substrata. 135 4

The enzymatic activities in post-mortem rat brain kept at 4 degrees C and at 25 degrees C were determined for a number of enzymes localized in specific cell types in the central nervous system. Choline acetyltransferase (CAT), glycerol-3-phosphate dehydrogenase (GPDH), glutamine synthetase (GS), lactate dehydrogenase (LDH) and 2',3'-cyclic nucleotide phosphohydrolase (CNPase) were found to be very stable at both 4 degrees C and 25 degrees C with only slight, if any, losses of activity being seen even at periods as long as 72 hr. Glutamic acid decarboxylase (GAD) activity was less stable than that of the other enzymes. In brains kept at 4 degrees C GAD activity was stable out to 24 hr after which it began to decline rapidly to 65% of control at 72 hr. In brains kept at 25 degrees C, GAD activity was stable for 6-8 hr and then began to steadily decline to 58% of control at 24 hr and 29% of control at 72 hr. Assuming that these enzymes have similar stabilities in post-mortem human brain, the effect of post-mortem delay in processing tissues may be of lesser significance than other factors with regard to the measured enzyme activities in human brain samples.
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PMID:Stability of neuronal and glial marker enzymes in post-mortem rat brain. 301 Jan 49

Four enzymes related to specific cell functions were assayed in rat sciatic nerve injury by crush (cr) or crush and ligation (cr-lig) after 2, 7, and 15 days in situ. Enzyme activities in segments of sciatic nerve proximal and distal to the injury were compared to those in corresponding segments of the contralateral nerve. Choline acetyltransferase (CAT) activity in the distal portion decreased by 65% for cr and almost to zero for cr-lig by day 7, while in the proximal portions CAT decreased to 70% of control values by 7 days and to 50% at 15 days after cr-lig. The activity of the Schwann cell-myelin-associated enzyme 2',3'-cyclic nucleotide phosphohydrolase (CNP) decreased slowly distal to the injury. Distal to both types of injury the lysosomal enzyme beta-glucuronidase (GLR) increased six- to eightfold by 15 days. Proximal to injury GLR also increased (P cr X 2.5, P cr-lig X 5) but the peak proximally was attained by day 7. Despite interruption of axonally transported enzymes, the activities of the metabolic enzyme creatine kinase (CK) increased distal to injury apparently reflecting changes in the functions of the Schwann cells. The loss of metabolic enzymes from the axonal compartment may be completely obscured by reciprocal changes in the non-neuronal compartments if the activity is present in both compartments.
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PMID:Enzyme changes in axon, myelin, and Schwann cells in injured sciatic nerve. 631 Jan 39