Action of phospholipase A2 of rabbit neuronal and glial cells on 1,2-diacyl-, 2-acyl-1-alk-1'-enyl-, and 2-acyl-1-alkyl-glycerophosphatides.

Pronounced differences in the phospholipase A2 activities were found in neurons and glia, the enzyme activity being two- to threefold higher in neurons than in glial cells. Both phospholipases A2 hydrolyzed the 1,2-diacylglycerophosphatides more rapidly than the acylalkyl and acylalkenyl compounds. Choline plasmalogen and the corresponding alkyl derivative were cleaved at similar rates by the phospholipase A2 from both glia and neurons. There was a tendency by the neuronal phospholipase A2 to release arachidonic acid faster than linolenic acid from both phosphatidylcholine and -ethanolamine, while arachidonic acid was removed less actively from phosphatidylethanolamine by the glial enzyme. The glial phospholipase A2 showed a lag period of 10 or 20 min. Norepinephrine, injection into the lateral ventricle of the rabbit brain, stimulated the hydrolysis of the various 1,2-diacyl-, acylalkyl, and and acylalkenyl-glycerophosphatides by the phospholipase A2 from both glia and neurons.

[32P-incorporation in adenosine phosphates of the rat brain after oral application of vincamine for 2 weeks (author's transl)]. / Der 32P-Einbau in Adenosinphosphate des Rattengehirns nach 2wöchiger oraler Verabreichung von Vincamin.

The 32P-incorporation into the adenosine phosphates AMP, ADP and ATP of the rat brain after an oral administration of a daily dose of 20 mg/kg 14,15-dihydro14 beta-hydroxy-(3 alpha,16 alpha)-eburnamenine-14-carbonic acid methylester (vincamine; Vincapront) during two weeks was determined. The concentrations of the three adenosine phosphates did not change. After the administration of vincamine the increase in the 32P-incorporation into AMP and ADP was statistically significant. The results obtained are discussed in regard to an acceleration of the pentose phosphate shunt and an activation of adenylate kinase.

[Applied neurochemistry (author's transl)]. / Angewandte Neurochemie.

Metabolic disorders may also be accompanied by neurological symptoms. Diagnosis is ofter difficult because clinical opportunities are rare. But some things can be detected even by simple means. In particular, primary biochemical disturbances are discussed, insofar as they may have an unfavorable effect on the nervous system. Among these are hypoglycemia, hyperglycemia, cerebral nutritional disorders, phenylketonuria. Wilson's disease, folic acid deficiency and acute intermittent porphyria.

[The 32P-incorporation into nucleic acids and adenosine phosphates of the rat brain after acute and chronic influence of meclofenoxate (author's transl)]. / 32P-Einbau in Nukleinsäuren und Adenosinphosphate des Rattengehirns nach akuter und chronischer Einwirkung von Meclofenoxat

Beta-Dimethylaminoethyl-p-chlorophenoxyacetate hydrochloride (meclofenoxate, Helfergin) was adminstered orally in dosages of 300 mg/kg 3 times during an 18-h period. The incorporation rate of the total and cytoplasmic RNA as well as of ATP, ADP and AMP decreased. Contradictory results were obtained after a 16-day treatment with orally 300 mg/kg per day: while the 32P-incorporation rate of the cytoplasmic RNA and the 3 adenosine phosphates increased, the nuclear RNA showed a correspondent diminishing. No changes of the ATP content could be observed in any group. The differences between the acute and chronic experiments could be explained by a different excitation of the animals and by the very different dosages. The increased 32P-incorporation into the cytoplasmic and into the adenosine phosphates in the chronic experiments are explained by a stimulation of the pentose phosphate shunt which yields mainly the phosphate group for the synthesis of AMP.

[The influence of naftidrofuryl on 32Pi-incorporation into nucleic acids and adenosine phosphates of the rat brain]. / Der einfluss von Naftidrofuryl auf den 32Pi-einbau in Nukleinsäuren und Adenosinphosphate des Rattengehirns

3-(1-Naphthyl)-2-tetrahydrofuryl-propionic acid-beta-diethylester-hydrogenoxalate (naftidrofuryl) increased after a 15-day treatment with orally 200 mg/kg per day the 32P-incorporation rate of two nucleic acid fractions and of ATP, ADP and AMP of rat brains. In contrast to the findings of other authors no increased ATP content was observed. The increased incorporation of the alpha-phosphate during the de novo synthesis of AMP.

On the activity of brain phospholipase A2 towards specifically labelled glycerophospholipids during subacute sclerosing panencephalitis.

1,2-Diacyl-sn-glycero-3-phosphorylcholine, -ethanolamine and -serine, specifically labelled with different fatty acids at either the 1- or 2-position, were prepared enzymatically using the acyltransferase system of rat liver microsomes. The substrates were subjected to hydrolysis by phospholipase A2 obtained from brain tissue of a normal and a case of subacute sclerosing panencephalitis (SSPE). In the pathological tissue and increase of approx. 50% in phospholipase A2 activity could be observed in comparison to that from the control brain for all investigated substrates. Experiments with phosphatidylethanolamines, specifically labelled with different fatty acids in the 2-position, revealed that the phospholipase A2 activity of the SSPE brain tissue was enhanced by about 50% when compared to the control brain regardless of the fatty acid constituent at the 2-position of the substrates.