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W Oelszner

Publications and source records attributed to W Oelszner.

At least 19 recordsLinked to original sources
PubMed1984

Comparison of two methods for estimating the acetylcholine turnover in discrete rat brain structures.

The acetylcholine turnover rate was determined in olfactory tubercle, nucleus accumbens and striatum of rat brain. The calculation of turnover rates was carried out by means of two different methods: a two compartment analysis and the finite differences method. After pulse injection of [3H]choline the radioactivity of both [3H]acetylcholine and [3H]choline was measured in the above mentioned brain areas. The contents of acetylcholine and choline were measured radioenzymatically. By using the two compartment model the following acetylcholine turnover rates were obtained: olfactory tubercle, 0.577; nucleus accumbens, 0.679; striatum, 1.110 (mumoles/g X hr). When using the finite differences method the values were: olfactory tubercle, 0.517; nucleus accumbens, 0.822; striatum, 1.115 (mumoles/g X hr). This demonstrates that the results obtained by applying the two different methods are nearly identical. Advantages and disadvantages of the two methods are discussed.

Acetylcholine↗
PubMed1980

Displacement of specific serotonin and lysergic acid diethylamide binding by Ergalgin, a new antiserotonin drug.

[3H]-serotonin and [3H]-lysergic acid diethylamide (LSD) bind with a high affinity, KD = 12 nM and 6 nM, respectively, to distinct receptors of rat caudate membranes in vitro. Displacement experiments with unlabeled serotonin and LSD support the hypothesis of serotonin receptors existing in an agonist and antagonist state. Methysergide and Ergalgin display quite similar potencies in displacing [3H]-serotonin and [3H]-LSD from their specific binding sites (Ki = 46,7 and 53,4 nM; 22,3 and 36,5 nM, respectively). Contrary to pharmacological findings these binding results are in favour of mixed agonist/antagonist properties of these compounds.

Animals↗
PubMed1980

[Analysis of acetylcholine turnover in small brain areas in the rat with a two-compartment model].

A two-compartment model was used to calculate the turnover of acetylcholine in the Tuberculum olfactorium and the Nucleus accumbens septi. Radioactivity of [3H]-acetylcholine and [3H]-choline was measured in the areas after pulse injection of [3H]-choline. Acetylcholine and choline were determined radioenzymatically. The time dependence of specific activity of both choline and acetylcholine pools was calculated with an exponential polynomial function on a 9825A desk computer (Hewlett Packard). From the parameters of these functions a compartment analysis was performed. It was possible to determine the acetylcholine turnover exactly only if the analysis was perfomed from the acetylcholine pool (compartment B). The data of our model are discussed in relation to the literature.

Acetylcholine↗
PubMed1976

Effect of arecoline on synaptosomal K+-phosphatase and (Na+ + K+)-ATPase.

Synaptosomal fractions and synaptosomal membranes from rat brain tissue were prepared and characterized enzymatically. Arecoline increased both the activity of K+-phosphatase in incubated synaptosomal fractions and the (Na+ + K+)-ATPase activity of synaptosomal membranes by 40% and 78%, respectively. This activation of ion transport processes is believed to be associated with increased ACh synthesis produced by arecoline.

Acetylcholine↗
PubMed1975

[Cholinergic effect on the dopamine turnover in the rat corpus striatum].

The peripheral administration of oxotremorine caused a significant increase in dihydroxyphenylacetic acid (DOPAC) in the striatum of rats, dopamine (DA) level was unaffected. Injection of oxotremorine into the substantia nigra failed to change the content of dopamine and its acid metabolites homovanillic acid (HVA) and DOPAC in striatum. Injection of oxotremorine or carbachol into the substantia nigra or into the caudate nucleus did not significantly influence the DA-turnover. The partly inconsistent results are discussed in connection with literature data in regard to the existence of excitatory as well as inhibitory cholinergic systems, which are located differently and are involved in the regulation of DA-turnover.

3,4-Dihydroxyphenylacetic Acid↗
PubMed1975

[Effect of various amino acids and their antagonists on the cholinergic tremor and acetylcholine release in the CNS of the rat].

Glycine and GABA administered intraventricularly and intrastriatally were found to inhibit the oxotremorin tremor in rats. The two amino acids reduce both the spontaneous release of acetylcholine into the ventricle and the discharge measured under oxotremorin treatment. The inhibition of the tremor and of acetylcholine release can be blocked by amino acid antagonists (strychnine and picrotoxin), whose effects are not specific for one of these amino acids; this action can be interpreted as effect of interference with other central transmission systems. Structures located close to the ventricles (nigrostriatal path ways) are discussed as possible points of action.

Acetylcholine↗
PubMed1975

Interaction between cellular metabolism and acetylcholine turnover of rat brain cortex slices in the presence of arecoline.

Centrally acting cholinomimetic drugs like arecoline stimulate active ion transport processes in the synaptic region. Regarding the connection between cellular metabolism and active Na"-K+-transport the effect of arecoline on the cerebral metabolic status was proved. Arecoline decreased the level of high energic phosphates and glycogen (energy charge diminished from 0,57 to 0,48) and increased the glucose consumption and lactate production. Thus, the increased rate of CoA acetylation via oxidative breakdown of pyruvate seems to be prerequisite for the cholinergically stimulated ACh synthesis.

Acetylcholine↗
PubMed1975

Serotonin content in the central nervous system of rats and cholinergic tremor.

Oxotremorine did not alter the level of 5-HT and 5-hydroxyindoleacetic acid in different brain regions. The content of 5-HT in the striatum was diminished by electrolytic lesions of the raphe system, by microinjection of the selective depletor 5,6-dihydroxytryptamine into the raphe system and inhibition of synthesis by pCPA or pCAM. The intensity of oxotremorine-induced tremor was reduced only in some experimental groups without clear-cut correlation to the decreased 5-HT levels. In pCPA-pretreated animals resoring of 5-HT concentration by intrastriatal microinjection of 5-HT and ip administration of 5-HT did not reestablish tremor intensity. There is no evidence that cholinergic tremor is triggered indirectly and depends upon an intact 5-HT system.

Animals↗
PubMed1975

Correlation between drug induced changes of acetylcholine release and acetylcholine fractions in rat brain.

After administration of eserine, a new acetylcholine (ACh) subfraction called f+ is formed in rat brain tissue. References and methods are given for the calculation of this subfraction, which can be isolated and determined only together with the so-called "free" ACh fraction. Alterations of the f+-ACh subfraction caused by barbital, urethane, pentetrazol, arecoline and scopolamine in telencephalon, cortex and striatum of rat brain are connected with changes of ACh concentrations determined in comparable releasing tests.

Acetylcholine↗