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Biomedical subjects

K Schlesinger

Publications and source records attributed to K Schlesinger.

At least 37 records · Page 2Linked to original sources

Levels of pyridoxine and susceptibility to electroconvulsive and audiogenic seizures.

The effects of pyridoxine deficiency and the administration of supplemental vitamin B6 on audiogenic and electroconvulsive seizures were studied in two inbred strains of mice and their F1 hybrids. Pyridoxine deficient diets increased seizure risk, whereas supplemental vitamin B6 protected these animals against seizures. Penicillamine and thiosemicarbazide, at doses which lowered brain levels of pyridoxine by only 10%, increased seizure risk. Diets deficient in zinc and copper did not alter susceptibility to either audiogenic or electroconvulsive seizures. DBA/2J mice, genetically susceptible to audiogenic seizures, have the same endogenous levels of pyridoxine in the brain as do C57Bl/6J mice, which are resistant to audiogenic seizures.

Acoustic Stimulation↗

Catechol-O-methyl transferase and monoamine oxidase activities in brains of mice susceptible and resistant to audiogenic seizures.

The activities of catechol-O-methyl transferase (COMT), monoamine oxidase (MAO), and a methanol forming enzyme were studied in whole brain homogenates and in livers obtained from DBA/2J, C57B1/6J, and F1 hybrid mice. DBA/2J mice are extremely susceptible to audiogenic seizures, whereas C57B1/6J mice are resistant to sound-induced convulsions. C57B1/6J mice were found to have significantly higher brain levels of COMT, while MAO activities were not different in animals of these genotypes. No methanol forming activity was detected in animals of either strain. No differences were found in hepatic activities of either COMT or MAO. Pyrogallol was shown to protect DBA/2J animals against audiogenic seizures.

Acoustic Stimulation↗

Induction of neuronal functions: acetylcholine-induced acetylcholinesterase activity in mouse neuroblastoma cells.

Addition of acetylcholine to growing cultures of mouse neuroblastoma cells induced a 37-fold increase in the specific activity of acetylcholinesterase (EC 3.1.1.7). Morphological changes, consisting of neurite-extensions, were also observed during the logarithmic phase of growth of cells stimulated with acetylcholine. A histochemical procedure for localization of acetylcholinesterase was used with the following results: (a) Cells differentiating by growth inhibition in serum-free medium do not stain positively for acetylcholinesterase, except when they have extended neurites, whereas all cells induced with acetylcholine, with or without neurites, stain positively for the enzyme. (b) The inverse relation between cell growth and induction of enzyme activity was demonstrated in nondividing cells at the center of a colony that do not incorporate thymidine into DNA and that stain positively for acetylcholinesterase, whereas actively dividing cells on the periphery of the colony do not stain for the enzyme. However, by addition of acetylcholine we were able to dissociate inhibition of cell growth from biochemical and morphological differentiation in mouse neuroblastoma cells.

Acetylcholine↗