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H Rösner

Publications and source records attributed to H Rösner.

At least 55 records · Page 3Linked to original sources
PubMed1982

Ganglioside changes in the chicken optic lobes as biochemical indicators of brain development and maturation.

The development profiles of 16 different gangliosides of the optic lobes of the chicken were followed from the sixth day of incubation to the tenth posthatching week and correlated to known morphological development. Several, previously undetected novel fractions occurred between the sixth and the tenth embryonic days. According to their migration rates on TLC-plates 4 of them may be GT3, GT2, GT1c, GQ1c. Three even more slowly migrating fractions represent penta-, hexa-, and septa-sialogangliosides. At the sixth day of incubation, characterized by maximal proliferation of neuroepithelial cells, the optic lobes contained predominantly GD3. Up to the eleventh day of incubation, parallel to decreased mitotic activity, maximal cell migration and neuron differentiation, GD3, GD2, and GT3 decreased in favor of newly detected polysialogangliosides. Thereafter, up to handling, parallel to increased growth and arborization of dendrites and axons as well as synaptogenesis, the newly detected polysialogangliosides decreased in favor of GD1b, GT1b, GQ1b, and GD1a. At hatching the myelin-specific GM4 appeared, reaching about 8% of total ganglioside sialic acid after 10 weeks. Likewise a fraction, migrating somewhat faster than GM1, increased. This band, named GM1', is suggested to be also myelin-associated. The other monosialogangliosides were always minor fractions, none exceeding 4% of total ganglioside sialic acid.

Aging↗
PubMed1982

Uniform distribution and similar turnover rates of individual gangliosides along axons of retinal ganglion cells in the chicken.

In 5-month-old chickens, an intracranial injection of N-[3H]acetylmannosamine led to a labeling of all optic lobe ganglioside species in a fashion paralleling the relative ganglioside distribution. In contrast, after an intraocular injection of the same precursor, the optic nerve and the optic lobe connected to the injected eye, possessed an exceptionally high labelling of GD1a (in comparison with GD1a-sialic acid), and only negligible incorporation of radioactivity into the myelin-specific GM4 and into a fraction migrating close to GM1. Subtracting both these very low labelling fractions from the total gave a percentage distribution of ganglioside sialic acid which now corresponded well to the distribution of radioactivity along the whole optic nerve, including the region of nerve terminals in the optic lobe. This pattern of ganglioside labelling, which indicates that GD1a carries about 60% of total ganglioside sialic acid of retinal ganglion cell axons, did not change remarkably during post-hatching development up to 5 months. Long-time incorporation studies revealed similar turnover rates of the main retinal ganglion cell gangliosides. The average half-lives were 34 (GD1a), 35 (GQ1b), 36.3 (GT1b) and 38.5 days (GD3). The findings suggest that the retinal ganglion cell axons and their presynaptic terminals possess a similar ganglioside pattern, characterized by a high content of GD1a.

Aging↗
PubMed1982

Effects of neonatal 6-hydroxydopamine treatment on cortical development in mice and rats as monitored by developmental changes of gangliosides.

In a comparative study newborn rats and mice received subcutaneous (s.c.) injections of 6-hydroxydopamine (6-OHDA: 100 mg/kg) on postnatal days (p.d.) 1-3. In rats the treatment permanently reduced synaptosomal 3H-noradrenaline (3H-NA) uptake in the cortex to about 50-60% of control values. Conversely, cortical 3H-NA uptake was only temporarily reduced in treated mice during the first week and central noradrenergic neurons completely recovered during the second and third week. The different response of mice and rats to 6-OHDA is suggested to be due to earlier maturation of the noradrenergic system in mice, making it less vulnerable to neonatal injections of the neurotoxin. To determine whether the development of the cortex would be altered after degeneration of its noradrenergic innervation, developmental changes of cortical ganglioside content and composition of 6-OHDA-treated animals were compared to that of littermate controls. In 18-day-old rats, where reduction of 3H-NA uptake had persisted, ganglioside content was reduced by 16.5%, indicating growth impairment of neuronal membrane structures. Cortical gangliosides of younger rats and all the stages studied in mice were not affected by 6-OHDA treatment.

Animals↗
PubMed1981

Isolation and preliminary characterization of novel polysialogangliosides from embryonic chick brain.

Preparative thin-layer chromatography was used to isolate from embryonic chick brains four different polysialogangliosides which moved below GT1b on TLC plates. These possessed molar sialic acid-to-sphingosine ratios of 4:1, 5:1, 6:1, and 7:1, respectively. Mild neuraminidase (Clostridium perfringens) treatment of the three most highly sialylated fractions gave GT1b and GD1b transiently, but the only accumulating ganglioside was GM1. All three polysialogangliosides were also found in Elasmobranch brains. During development of he chicken the concentrations of the two most slow-moving fractions ("hexa"-, and "septa" -sialogangliosides) decreased.

Animals↗
PubMed1979

Binding of d-tubocurarine by gangliosides.

The binding of d-tubocurarine by ganglioside mixtures from chicken and bovine brain as well as by the single gangliosides GGtet1-NeuAc, GGtet2aNeuAc and GGtet3aNeuAc was demonstrated by means of equilibrium gel filtration. The sialyl-oligosaccharide derivatives of GGtet1NeuAc and GGtet2aNeuAc, however, did not bind any d-tubocurarine. A lack of binding was also found for the gangliotetraosyl-ceramide GgOse4Cer, free NeuAc, mucin and sphingomyelin. Under saturation conditions, GGtet1NeuAc bound 0.58, GGtet2aNeuAc 0.92 and GGtet3a-NeuAc 1.23 mol d-tubocurarine per mol ganglioside. Half-maximal binding was achieved between 1 and 1.5 x 10(-5)M d-tubocurarine. Ca2 was found to inhibit the binding of d-tubocurarine to gangliosides (50% at 4 x 10(-4)M Ca2). Mg2 was about 4 times less effective. Acetylcholine caused a 40% inhibition at 4 x 10(-3)M, whereas K and Na had only slight effects even at 5 x 10(-2)M.

Animals↗
PubMed1979

[The complexing ability of gangliosides for Ca2, I. Influence of mono- and divalent cations and of acetylcholin (author's transl)].

The binding of Ca2 to single ganglioside species (GGtet1NeuAc, GGtet2aNeuAc, GGtet 3aNeuAc), to their free, reducing sialyl-oligosaccharides and to ganglioside mixtures from chicken brain was investigated by means of ion-sensitive electrodes (potentiometry). Unlike the sialyl-oligosaccharides and free N-acetylneuraminic acid, gangliosides were found to possess two different modes of binding for Ca2, depending on the total concentration of Ca2. This was mainly indicated by a release of up to 75% of previously bound Ca2 after raising the total Ca2-concentration above a critical level of about 5--9 X 10(-5)M. Addition of acetylcholin (9mM), Li, K, and Na, respectively, caused a release of Ca2 from ganglioside-Ca2-complexes (0.1mM Ca2, 0.1mM ganglioside-NeuAc) in the sequence: acetylcholin : Li : K : Na = 4 : 3 : 1 : 1 composed on molar basis (9mM).

Acetylcholine↗
PubMed1977

[Binding of colchiceine to isolated gangliosides and ganglioside-containing membranes (author's transl)].

The binding of the alkaloid colchicine and its metabolite colchiceine to different membranes and gangliosides has been investigated. In contrast to colchicine, colchiceine binds to erythrocyte ghosts, plasma membranes of rat liver and heart muscle, and synaptosomes of rat brain. The binding properties of isolated gangliosides are analogous to those of the membranes investigated. On a molar basis the binding capacities of the gangliosides GT1, GD1a and GM1 for colchiceine are 7:4:1, respectively. The binding of alkaloid to ganglioside structures is diminished in the presence of EDTA and after pretreatment with neuraminidase, suggesting a specific, Ca2 -dependent interaction of colchiceine with gangliosides. The results are discussed with respect to the different biological activities of colchicine and its metabolite colchiceine.

Animals↗
PubMed1976

[Effect of chlorpromazine on the incorporation of sialic acid into gangliosides and glycoproteins of the chicken brain (author's transl)].

Three-days-old White Leghorn chickens were used to study the effect of i.p.-injected chlorpromazine (CP, 2.5 or 5 mg/animal) on the incorporation of N-(3H)-acetylmannosamine into glycoprotein- and ganglioside-bound sialic acid and 14C-histidine into the proteins of the cerebrum, the optic lobes, and the cerebellum after incorporation periods of 1-24 h. All experiments were performed under constant temperature conditions. 1. The incorporation of 14C-histidine into the proteins of the optic lobes was not influenced by CP. 2. Within 24 h in the optic lobes neither the concentration of particle-bound sialic acid (mug sialic acid/mg protein) nor the content of radioactive-labeled sialic acid precursor was affected by the drug. 3. The rate of incorporation of labeled sialic acid into glycoproteins and gangliosides, however, was up to 6 h after the injection of the precursor much lower in the CP-treated animals than in controls. This may indicate, that the turnover of sialo-compounds was diminished by CP. 4. The inhibition was the most intensive in the cerebrum (up to 80%), lower in the optic lobes (up to 70%), and only small in the cerebellum (up to 20%), but was always the same for glycoproteins and gangliosides. The different inhibition rates in the different structures may indicate a correlation between the pharmacologic, sedative effects of the drug and the diminished turnover of sialo compounds.

Animals↗
PubMed1975

Incorporation of sialic acid into gangliosides and glycoproteins of the optic pathway following an intraocular injection of [N-3H]acetylmannosamine in the chicken.

Following an intraocular (i.o.) injection of [N-3H]acetylmannosamine, low molecular soluble radioactive label is distributed rapidly along the optic pathway. At the same time glycoproteins and gangliosides were found radioactively labelled in the distal parts of the optic pathway. Negligible amounts of radioactivity were incorporated into the same structures via the blood. The present data confirm, that glycoproteins are transferred in the retinal ganglion cells by a rapid axonal transport mechanism towards the nerve endings. Unlike glycoproteins labelled gangliosides accumulated in the optic nerves up to 4 days after the precursor injection. Simultaneously radioactive material, soluble in TCA/PTA, disappeared from the optic nerves. The specific radioactivities (disint./min/mug NeuNAc) of the single ganglioside fractions of the optic lobes, which contain the nerve endings of the retinal ganglion cells, differed considerably. Especially one fraction, moving on TLC plates identically to 'GD1a', was up to 20 times higher labelled than the other gangliosides. After an intracerebral injection of the same precursor, radioactivity was incorporated into the ganglioside fractions of the optic lobes to the same extent.

Animals↗