scholarly journals Choline acetyltransferase activity of spinal cord cell cultures increased by co-culture with muscle and by muscle-conditioned medium

1977 ◽  
Vol 74 (1) ◽  
pp. 16-29 ◽  
Author(s):  
EL Giller ◽  
JH Neale ◽  
PN Bullock ◽  
BK Schrier ◽  
PG Nelson
Keyword(s):  
Spinal Cord ◽  
Molecular Weight ◽  
Conditioned Medium ◽  
Choline Acetyltransferase ◽  
Membrane Filtration ◽  
Active Material ◽  
Muscle Cells ◽  
Blocking Agent ◽  
Acid Decarboxylase ◽  
Undifferentiated Cells

Activity of the enzyme choline acetyltransferase (CAT), which mediates the synthesis of the neurotransmitter, acetylcholine, was increased up to 20- fold in spinal cord (SC) cells grown in culture with muscle cells for 2 wk. This increase was directly related to the duration of co-culture as well as to the cell density of both the SC and muscle involved and was not affected by the presence of the acetylcholine receptor blocking agent, α-bungarotoxin. Glutamic acid decarboxylase (GAD) activity was often markedly decreased in SC-muscle cultures while the activities of acetylcholinesterase and several other enzymes were little changed. Increased CAT activity was also observed when SC cultures were maintained in medium which had been conditioned by muscle cells or by undifferentiated cells from embryonic muscle. Muscle-conditioned medium (CM) did not affect the activities of SC cell GAD or acetylcholinesterase. Dilution or concentration of the CM directly affected its ability to increase SC CAT activity , as did the duration and timing of exposure of the SC cells to the CM. The medium could be conditioned by muscle cells in the presence or absence of serum, and remained effective after dialysis or heating to 58 degrees C. Membrane filtration data were consistent with the conclusion that the active material(s) in CM had a molecular weight in excess of 50,000 daltons. We conclude that large molecular weight material that is released by muscle cells is capable of producing a specific increase in CAT activity of SC cells.

scholarly journals A New Human Low Molecular Weight Granulocyte Colony Stimulating Activity

Blood ◽  
1973 ◽  
Vol 42 (3) ◽  
pp. 341-348 ◽  
Author(s):  
G. B. Price ◽  
E. A. McCulloch ◽  
J. E. Till
Keyword(s):  
Molecular Weight ◽  
Conditioned Medium ◽  
Human Peripheral Blood ◽  
Marrow Cell ◽  
Active Material ◽  
Gel Filtration ◽  
Low Molecular Weight ◽  
Peripheral Blood Leukocytes ◽  
Blood Leukocytes ◽  
Colony Stimulating Activity

Abstract Fractionation of conditioned medium derived from cultures of human peripheral blood leukocytes by ultrafiltration yielded material of low molecular weight, capable of stimulating the formation of granulopoietic colonies by human marrow cells in culture. The molecular weight of the active material was found to be less than that of vitamin B12 (1330 mol wt) on the basis of gel filtration on Sephadex G-25. The low molecular weight colony-stimulating activity (LMW-CSA) was trypsin-sensitive, and extractable into chloroform or diethyl ether. Unlike unfractionated leukocyte-conditioned medium, the LMW-CSA showed no colony-stimulating activity when tested on mouse, rather than human, marrow cell cultures.

Activities of acetylcholinesterase, choline acetyltransferase, and catecholamine production in the spinal cord of the axolotl Ambystoma mexicanum during forelimb regeneration

1994 ◽  
Vol 72 (5-6) ◽  
pp. 188-194 ◽  
Author(s):  
Patrick Scaps ◽  
François Bernet ◽  
Jean Gautron ◽  
Bénoni Boilly
Keyword(s):  
Spinal Cord ◽  
Molecular Weight ◽  
Choline Acetyltransferase ◽  
Control Level ◽  
Limb Regeneration ◽  
Nerve Fibers ◽  
Ambystoma Mexicanum ◽  
Limb Amputation ◽  
Metabolic Activities ◽  
Molecular Weight Form

Amputation of an axolotl limb causes severance of the brachial nerves, followed by their regeneration into a blastema. It is known that these nerves provide a neurotophic factor to blastemal cells. To approach the problem of the response of spinal cord nerve centers to forelimb amputation, we have studied biosynthetic activities in the nerve centers involved in axonal injury during limb regeneration. We report that the acetylcholinesterase (AChE) activity in the spinal cord is elevated 2 days (+ 69%) and 7 days (+ 28%) after limb amputation compared with levels in unamputated control animals, but is not significantly elevated at 3 h or 15 days. The percentages of slow (3.6 S and 6.0 S) and fast (18 S) sedimenting forms of AChE progressively decrease 2 and 7 days after amputation, while those of intermediate sedimenting forms (10.5 S and 14.0 S) increase. Fifteen days after amputation, lower molecular weight forms return to the control level, but the heavy molecular weight form of AChE is absent as at 7 days; consequently intermediate molecular weight forms are in a greater proportion than the other two forms. Choline acetyltransferase activity was measured only 2 days after amputation (when AChE was at its highest level). It increases by about 34% with regard to the controls. Adrenaline is higher than controls 2 days after amputation, while noradrenaline is not significantly modified. The metabolic changes observed in the spinal cord during limb regeneration probably are the result of a general reaction to the stress of amputation (transection of brachial nerves) and regeneration of nerve fibers, since similar metabolic activities were observed after a simple denervation of the two unamputated forelimbs.Key words: acetylcholinesterase, choline acetyltransferase, catecholamines, regeneration, axolotl.

Role of electrical activity and trophic factors during cholinergic development in dissociated cultures

1986 ◽  
Vol 64 (3) ◽  
pp. 356-362 ◽  
Author(s):  
Douglas E. Brenneman
Keyword(s):  
Spinal Cord ◽  
Electrical Activity ◽  
Conditioned Medium ◽  
Trophic Factors ◽  
Acid Decarboxylase ◽  
Gaba Uptake ◽  
Decarboxylase Activity ◽  
Spinal Cord Neurons ◽  
Dose Dependent

The role of electrical activity in the developmental regulation of cholinergic neurons was investigated in dissociated spinal cord – dorsal root ganglion (SC-DRG) cultures. Application of tetrodotoxin (TTX) during the first 6 days after plating had no effect on choline acetyltransferase (CAT) activity. Suppression of electrical activity during the 7th day decreased CAT to 68% of control. These decreases in CAT activity were still apparent 2 weeks after removal of the TTX. GABAergic neurons, as indicated by glutamic acid decarboxylase activity and high affinity [3H]GABA uptake, were not affected by TTX treatment. Addition of 8-bromo-cAMP or conditioned medium obtained from SC-DRG cultures at certain developmental periods produced dose-dependent increases in CAT levels on TTX-treated cultures as compared with those treated with TTX alone. Similar studies with 8-bromo-cGMP revealed no significant effects on CAT activity. Vasoactive intestinal peptide (VIP) produced a dose-dependent increase in CAT activity when added to cultures between days 12 and 14. Similar studies conducted on younger cultures (days 5–7) or older cultures (days 21–23) revealed no increases in CAT activity. Addition of 0.1 nM VIP to TTX-treated cultures resulted in CAT levels which were not significantly different from those of electrically active controls. These data suggest that cyclic AMP, VIP, and trophic substances in conditioned medium may have roles in the mechanism of cholinergic toxicity produced by electrical blockade of developing spinal cord neurons.

Choline Acetyltransferase Activity Is Increased in Combined Cultures of Spinal Cord and Muscle Cells from Mice

Science ◽  
1973 ◽  
Vol 182 (4112) ◽  
pp. 588-589 ◽  
Author(s):  
E. L. Giller ◽  
B. K. Schrier ◽  
A. Shainberg ◽  
H. R. Fisk ◽  
P. G. Nelson
Keyword(s):  
Spinal Cord ◽  
Choline Acetyltransferase ◽  
Muscle Cells ◽  
Acetyltransferase Activity ◽  
Combined Cultures ◽  
Choline Acetyltransferase Activity
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