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H Matthaei

Publications and source records attributed to H Matthaei.

At least 19 recordsLinked to original sources
PubMed1988

Stereoselectivity of noradrenaline uptake into synaptic vesicles of the rat brain.

To investigate the stereoselectivity of the ATP-Mg2+-dependent uptake of noradrenaline, synaptic vesicles were isolated from the rat brain by differential centrifugation and incubated with 3H-(+/-)-, 3H-(-)- or 14C-(+)-noradrenaline in the absence and in the presence of ATP-Mg2+. The Km values of the ATP-Mg2+-dependent uptake were found to be different for the two isomers (mumol/l): 3H-(+/-)-noradrenaline 14.9 +/- 2.2 x 10(-1), 3H-(-)-noradrenaline 7.7 +/- 0.5 x 10(-1), 14C-(+)-noradrenaline 17.3 +/- 3.7 x 10(-1), whereas the Vmax of the racemate was identical with those of the two isomers (pmol/mg protein/min): 3H-(+/-)-noradrenaline 5.5 +/- 0.4, 3H-(-)-noradrenaline 4.9 +/- 0.1, 14C-(+)-noradrenaline 5.1 +/- 0.4. Moreover, (+)-noradrenaline inhibited competitively the ATP-Mg2+-dependent uptake of 3H-(+/-)-noradrenaline (Ki 19.2 +/- 1.0 x 10(-1) mumol/l) and 3H-(-)-noradrenaline (Ki 17.7 +/- 1.8 x 10(-1) mumol/l), the Ki values being nearly identical with the Km of the ATP-Mg2+-dependent uptake of 14C-(+)-noradrenaline. It is concluded that the ATP Mg2+-dependent uptake of noradrenaline into synaptic vesicles of the rat brain is stereoselective and that both isomers share the same transport system.

Adenosine Triphosphate↗
PubMed1986

Increase of circulating beta-endorphin-like immunoreactivity correlates with the change in feeling of pleasantness after running.

Twenty-one male regular long distance runners participated in two 10 km runs one week apart. Their beta-endorphin-like immunoreactivity (beta-EIR) was assayed in plasma before and immediately after running. Mood was monitored by an adjective check list (Eigenschaftswörterliste, EWL) pre- and post-run. beta-EIR was significantly elevated post-run. Self-reliance and good mood scored higher after running. Both mood elevation and plasma beta-EIR increase showed a considerable individual variability but there was a significant correlation in the mean values of the two runs between individual beta-EIR increases (delta beta-EIR) and the changes of ratings in feeling of pleasantness (delta FP). High delta beta-EIR corresponded to positive mood change post-run.

Adult↗
PubMed1986

Endogenous benzodiazepine receptor agonist in human and mammalian plasma.

Using ultra-filtration steps and HPLC-separation, a low molecular weight ligand of the benzodiazepine receptor was isolated from plasma of various mammalian species including man. The endogenous ligand acts on benzodiazepine receptors agonistically and apparently has a receptor affinity similar to Diazepam. The ligand is not identical with Diazepam as indicated by HPLC and UV-spectroscopy.

Animals↗
PubMed1983

Three types of acetylcholine-induced single channel currents in clonal rat pheochromocytoma cells.

Single channel currents induced by acetylcholine were recorded from nerve growth factor-differentiated clonal rat pheochromocytoma (PC12) cells by using the patch-clamp technique. Inward current amplitudes were heterogeneous and could be related to three classes of unitary current. The three current-voltage relations were linear for patch membrane potentials ranging from -50 mV to -120 mV. At 22 degrees C, conductances of 22 pS, 31 pS and 39 pS were obtained. The extrapolated reversal potential for the channels was 0 mV and the mean open time approximately 10-20 ms. These results may indicate that PC12 cells possess three types of acetylcholine receptor channels.

Acetylcholine↗
PubMed1983

A method for defined sectioning of fresh young brains and collection of small regions for cell and tissue culture.

A method for the collection of defined small regions from fresh brain under sterile conditions is described. Its reproducibility allows the cultivation of well-defined, corresponding regions from similar brains. After controlled orientation in agarose, the brain can be sectioned by means of a Vibratome in spite of its softness. The section level is defined by co-ordinates of a stereotaxic atlas, produced for this purpose from brains orientated in the same way. Areas desired for cultivation are punched out from tissue slices with 200-550 microns diameter needles according to the atlas pictures. The plugs can then be stored in cold buffer solution until preparation for culture. Exact locations of tissue samples collected can be determined histologically. Either whole or dissociated plugs cultivated by a plasma clot technique lead to morphologically differentiating neurons surviving for more than or up to 14 days, respectively.

Animals↗
PubMed1983

Single neuron cultivation of embryonic and perinatal rabbit or rat brains based on plasma clot technique.

Isolated neuronal cells dissociated from the brain of embryonic rabbits on the sixteenth day of gestation and of perinatal rats (eighteenth embryonic day, to E18, thirteenth day postnatum, p.n. 13) were selectively cultured using a plasma clot technique. The cells grown were shown to be neurons by means of the neuron-specific synaptosomal plasma membrane antibody (SPM). They differentiated at a very high frequency from rounded cells lacking processes into different shapes characteristic for several neuronal cell types. Morphological differences could be distinguished even after 24 h in culture. The neurons differentiated in vitro for up to 11 days, apparently without need of any direct intercellular contact. Cells caught inside the plasma clot were prevented from decreasing in number. This provides the opportunity to culture few neurons even from an extremely small area of a single brain. As an example, different cell types are shown originating from rat cerebella aged E18 to p.n. 13. Their appearance apparently corresponds to the genesis of cerebellar cell types, as is known from the in vivo situation. The high degree of characteristic neuronal differentiation and the prevention of direct intercellular contacts indicate that this culture method may serve as an in vitro assay for genetically fixed properties acquired in vivo.

Animals↗
PubMed1982

The effects of D- and/or L-aspartic acids on the total weight of body, the weights of certain organs, and their protein, triglyceride and glycogen content.

125 rats which were divided into five groups were deprived of food or given orally D- (a potent inhibitor for L-asparaginase) and/or L-aspartic acids (Asp) for one week. The body weights before and at the end of the experiment were determined as well as post mortem the weights of brain, liver and kidneys, their protein contents, and the liver triglyceride and glycogen contents. D- and D+L-Asp caused significant decreases in the weights of body and liver, and in daily fluid intake; in addition liver and kidney protein, and liver triglyceride and glycogen contents were found to be lower than control. On the other hand, the food-deprived group which was subjected to more or less the same body weight loss due to food deprivation showed only a decrease in the liver triglyceride content. Since D-amino acids cause naloxone reversible analgesia which is, thus, considered as an involvement of endorphinergic system and of vasopressin, the effects of D-Asp were attributed to the changes in the availability of opioids and vasopressin, which simultaneously have an effect on each other as well as an effect of the release of ACTH. L-Asp appeared to antagonize the effects of D-Asp. Because L-Asp antagonizes the acute and chronic effects of morphine, including that on L-asparaginase activity, the hypothesis is proposed that the antagonizing effects of L-Asp observed may be caused at the level of L-asparaginase activity.

Animals↗
PubMed1981

Immunochemical evidence for exocytosis in isolated chromaffin cells after stimulation with depolarizing agents.

After chemical stimulation with depolarizing agents (Ba2+ or Ca2+/carbachol) isolated living chromaffin cells display a drastically increased binding capacity for anti-DBH, distributed spotwise on or near the outer cell membrane. This effect is inhibited by noradrenaline; it is not evoked by the non-exocytotically releasing agents tyramine and reserpine. the effect of apparent externalization of DBH is paralleled by the observation of a DBH-dependent binding of 125I-labelled protein A upon the same depolarizing stimuli. These observations are discussed as possible evidence for exocytotic activities.

Animals↗
PubMed1979

Post mortem changes in adenylate cyclase activity in rat brain striatum.

Adenylate cyclase activity in rat striatum decreased post mortem. Half-lives were about 2.7 h at 22 degrees C, 72 h at 4 degrees C. Differences in stability after death of adenylate cyclase in human brain and rat striatum, and possible heterogenity of the enzyme, are briefly discussed.

Adenylyl Cyclases↗
PubMed1976

Tissue specificity of nonhistone proteins from human chromatin.

Nonhistone proteins were isolated from human placental and tonsillar chromatins. Antiserum was prepared against a complex from some nonhistone proteins and DNA (NP-DNA) from placental chromatin. With the help of polyacrylamide gel electrophoresis and immunological methods the tissue specificity of human chromatin nonhistone proteins was established. The described organ immunogenic specificity of the complex of DNA and nonhistone protein (NP-DNA) from human chromatin is in accordance with data published on similar complexes from different animal organs. Besides, it is shown that shearing of chromatin leads to large chifts in NP-DNA concentrations required for maximum complement fixation in the presence of the prepared antiserum. This may probably be due to a damage of certain chromatin super structures which involve some of the nonhistone proteins and DNA sequences from both the more condensed and less condensed parts of chromatin.

Antibodies↗
PubMed1976

Competition of some biogenic amines for uptake into synaptic vesicles of the striatum.

Synaptic vesicles were isolated from the caudate nucleus of the pigs by differential centrifugation and incubated with labelled monoamines in the absence or in the presence of ATP-Mg(2+). Addition of ATP-Mg(2+) enhanced the uptake of (14)C-dopamine into the vesicles. Serotonin competitively inhibited the ATP-Mg(2+)-dependent uptake of (14)C-dopamine without influencing the uptake which took place in the absence of ATP-Mg(2+). Likewise, dopamine caused a dose-dependent inhibition of the ATP-Mg(2+)-dependent uptake of (14)C-serotonin without inhibiting the uptake in the absence of ATP-Mg(2+). Incubation of the vesicles with equal concentrations of(3)-dopamine and (14)C-serotonin revealed that the presence of the one amine competitively inhibited the ATP-Mg(2+)-dependent uptake of the other. Tyranimine competitively inhibited the ATP-Mg(2+)-dependent uptake of (14)C-dine, (14)C-serotonin and (14)C-noradrenaline into the vesicles; the uptake of the amines which took place in the absence of ATP-Mg(2+) was not impairedby tyramine. Analysis of the amine uptake by the ABC test showed that a mutual inhibition exists between dopamine and serotonin for the uptake into the synaptic vesicles. GABA did not influence the uptake of (14)C-dopamine either in the absence, or in the presence of ATP-Mg(2+)...

Adenosine Triphosphate↗
PubMed1975

Uptake of dopamine into fractions of pig caudate nucleus homogenates.

Homogenates of the caudate nucleus of the pig were submitted to differential centrifugation. The 20000 g and 80000 g fractions were isolated and a part of them was osmotically shocked. The highest dopamine content per mg protein was found in the intact 80000 g fraction. Incubation experiments with the intact and the osmotically shocked fractions at 25 degrees C revealed that the particles of the intact 20000 g fraction took up dopamine, the influx of the amine was not enhanced by addition of ATP and magnesium to the incubation medium. On the other hand after osmotic shock the uptake of dopamine into the particles of this fraction was greatly enhanced by addition of ATP and magnesium. The uptake of dopamine into the particles of both intact and osmotically shocked 80000 g fractions was likewise enhanced by ATP and magnesium. The uptake in all fractions was not influenced by ouabain. The influx of dopamine into the particles of the intact 80000 g fraction was competitively inhibited by reserpine (Ki0.96 x 10-8M) and prenylamine (Ki1.74 x 10-8M). It is concluded that the intact 20000 g fraction contains intact synaptosomes; the uptake of dopamine is independent of the presence of ATP and magnesium. The shocked 20000 g fraction and the 80000 g fractions contain synaptic vesicles; the uptake of dopamine into these vesicles is enhanced by ATP and magnesium.

Adenosine Triphosphate↗
PubMed1975

Uptake of serotonin, gamma-aminobutyric acid and histamine into synaptic vesicles of the pig caudate nucleus.

Dopamine-containing vesicles were isolated from the caudate nucleus of the pig by differential centrifugation and incubated with 14-C-serotonin (14-C-5-HT), 14-C-gamma-aminobutyric acid (14-C-GAGA), 14-C-dopamine or 14-C-histamine. At 25 degrees C the uptake of 14-C-5-HT and 14-C-GABA was enhanced by ATP and magnesium. The Km for the uptake of 14-C-5-HT in the presence of ATP and magnesium was 0.67 x 10-6M, that of 14-C-GABA 1.33 x 10-4M. 14-C-Histamine was also taken up into the vesicles but its uptake was not incluenced by ATP and magnesim. The ATP-magnesium-dependent uptake of 14-C-5-HT and 14-C-GABA was abolished at 0 degrees C. At 37 degrees C the accumulation of 14-C-GABA in the presence of ATP and magnesium reached a steady state after 20 min, while the accumulation of 14-C-5-HT reached a maximum after 2.5 min of incubation and then gradually declined. Osmotic lysis of the vesicles followed by sonication abolished the enhanced uptake of 14-C-GABA, 14-C-5-HT and 14-C-dopamine in the presence of ATP and magnesium. Determination of the endogenous contents of the vasicles revealed 14.6 pmoles per mg protein for 5-HT and 22.7 nmoles per mg protein for GABA. It is concluded that the caudate nucles preparation used in this study contains not only dopamine-storing vesicles able to take up biogenic amines but also GABA-containing vesicles which take up GABA by an ATP-magnesium-dependent process.

Adenosine Triphosphate↗