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H Winkler

Publications and source records attributed to H Winkler.

At least 145 records · Page 8Linked to original sources
PubMed1993

Distribution of secretoneurin, a peptide derived from secretogranin II, in rat brain: an immunocytochemical and radioimmunological study.

The distribution of secretoneurin, a peptide derived from its precursor secretogranin II by proteolytic processing, was studied in the central nervous system of the rat by immunocytochemistry and radioimmunoassay and compared to the distribution of secretogranin II messenger RNA by using in situ hybridization. With a specific antiserum a distinct staining of fibers and to a lesser extent also of perikarya was observed throughout the central nervous system. A high density of immunoreactive fibers and terminals was found in several brain areas, i.e. the lateral septum, the medial parts of the amygdala, some medial thalamic nuclei, the hypothalamus, habenula, nucleus interpeduncularis, locus coeruleus, nucleus tractus solitarii, the substantiae gelatinosae of the caudal trigeminal nucleus and of the spinal cord. The quantitative distribution as measured by a radioimmunoassay agreed well with the varying densities of immunoreactivity found by immunocytochemistry. The highest concentrations of this peptide were present in the hypothalamus, in particular, in the median eminence and are comparable to those of the most highly concentrated neuropeptides. The distribution of immunopositive perikarya corresponded well with that of secretogranin II messenger RNA obtained by in situ hybridization. The pattern of secretoneurin expression in rat brain was widespread and unique, partially overlapping with established chemical transmitters and neuropeptides. The functional significance of this new brain peptide remains to be established.

Animals↗
PubMed1993

Chromogranin A, secretogranin II and vasoactive intestinal peptide in phaeochromocytomas and ganglioneuromas.

By means of immunohistochemistry we analysed the distribution of chromogranin A, secretogranin II and vasoactive intestinal peptide (VIP) in 16 phaeochromocytomas, two cases of combined phaeochromocytoma-ganglioneuroma and four adrenal ganglioneuromas. Chromogranin A was found in the majority of phaeochromocytes and in mixed phaeochromocytomas-ganglioneuromas. Secretogranin II was present to a lesser degree in phaeochromocytes, but strong immunostaining was found in most ganglion cells of phaeochromocytomas, in the ganglioneuroma component of combined tumours and in adrenal ganglioneuromas. Vasoactive intestinal peptide was present in some ganglion cells of phaeochromocytomas, in the ganglioneuroma component of mixed tumours and in three of four adrenal ganglioneuromas. On semi-adjacent sections a co-localization of VIP and secretogranin II was demonstrated. These results indicate that neuronal differentiation is accompanied by an increased immunohistochemical expression of secretogranin II. Therefore, secretogranin II may be a useful marker for ganglion cell differentiation.

Adrenal Gland Neoplasms↗
PubMed1993

Concomitant changes of messenger ribonucleic acid levels of secretogranin II, VGF, vasopressin and oxytocin in the paraventricular nucleus of rats after adrenalectomy and during lactation.

In situ hybridization was used to study the mRNA levels for secretogranin II and VGF in comparison with those of oxytocin and vasopressin in the hypothalamus of rats. VGF is a widespread constituent of large dense core vesicles which is selectively induced in PC12 cells by nerve growth factor. After adrenalectomy the mRNA levels of secretogranin II, VGF and vasopressin were increased 4- to 5-fold in the parvocellular neurons of the paraventricular nuclei. In lactating rats the message for oxytocin and secretogranin II were significantly elevated in the magnocellular neurons of the paraventricular and supraoptic nuclei, whereas for VGF only a smaller non-significant increase was observed. As shown by immunoelectron microscopy secretoneurin (a peptide derived from secretogranin II) and oxytocin are co-stored in the large dense core vesicles of the hypothalamo-neurohypophysial neurons. These results demonstrate that stimulation of both parvo- and magnocellular neurons of the hypothalamus induces a concomitant increase of the messages for secretogranin II and VGF together with those of vasopressin and oxytocin.

Adrenalectomy↗
PubMed1993

Secretogranin II is synthesized and secreted in astrocyte cultures.

Astrocyte cultures from rat brain were analyzed for their ability to synthesize and secrete secretogranin II (chromogranin C). Northern blot analysis of polyA-selected RNA established the presence of secretogranin II mRNA in these cells. By radioimmunoassay, 11.6 fmol/10(6) astrocytes of secretogranin II was found in these cells. About twice the amount was released into the medium within 3 days. Secretogranin II within the astrocytes was practically unprocessed, as shown by HPLC. These results establish for the first time that astrocytes in vitro synthesize and secrete a protein of the acidic chromogranin family.

Animals↗
PubMed1993

Messenger RNA levels of chromogranin B, secretogranin II, and VGF in rat brain after AF64A-induced septohippocampal cholinergic lesions.

The mRNA levels of secretogranin II, chromogranin B, and VGF were compared in brains of control and AF64A-treated rats. This toxin induces specific lesions of the septohippocampal cholinergic pathway. As a consequence of this treatment, the chromogranin B message was elevated in the dentate gyrus granule cells of the hippocampus. In the paraventricular nucleus of the hypothalamus, a concomitant elevation of the messages of secretogranin II and corticotropin-releasing factor occurred in the parvocellular neurons, and an increase of those of secretogranin II and VGF occurred in a subgroup of magnocellular neurons. Further increases for secretogranin II were seen in the amygdaloid nuclei and the reticular thalamic nuclei and increases for chromogranin B in the temporal cortex, substantia nigra compacta, and ventral tegmental area. These results indicate that the toxin-induced lesion of the cholinergic pathway innervating the hippocampus apparently leads to the stimulation of several defined groups of neurons that react with an increase in the mRNA levels of their secretory peptides. We suggest that changes in mRNA expression of these peptides are useful parameters for defining neurons under chronic stimulation.

Acetylcholine↗
PubMed1993

Glycoprotein III (clusterin, sulfated glycoprotein 2) in endocrine, nervous, and other tissues: immunochemical characterization, subcellular localization, and regulation of biosynthesis.

Specific antisera were raised against the A and B chains of glycoprotein III. Immunoblotting revealed that in adrenal medulla both chains migrate very closely together in two-dimensional electrophoresis. Both chains with slightly differing molecular sizes are found in several endocrine tissues and in brain, kidney, liver, and serum. The mRNA has an analogous widespread distribution. In primary cultures of chromaffin cells the level of message becomes significantly increased by treatment with histamine or 12-O-tetradecanoylphorbol 13-acetate/forskolin. However, the increase is small when compared with that of secretogranin II. The subcellular localization of glycoprotein III in endocrine organs and in the posterior pituitary was investigated by subcellular fractionation and immunoelectron microscopy. Glycoprotein III was found to be confined to the large dense-core vesicles of these organs. For a discussion of the function of glycoprotein III, its localization in these organelles has to be taken into account.

Animals↗
PubMed1993

Seminal vesicle congestion as a cause of postprostatectomy dysuria.

A series of benign prostatic hypertrophy patients were routinely evaluated, including transrectal echography, before and at regular intervals following surgery. Five patients had persistent symptoms of dysuria at 14-30 months after surgery. There was no infection, residual urine or malignancy to explain their symptoms. The seminal vesicles (SVs) were severely dilated on transrectal echography, a finding which was definitely not present on initial examination. The patients were treated by transrectal echo-guided aspiration of the SVs by the perineal approach. The fluid aspirated was examined, and antibiotics were directly injected into the SVs. In 4 of the patients, there was a dramatic relief of symptoms with prolonged improvement. In only 1 case, following transurethral resection, there was but slight improvement. Dilated, obstructed SVs after prostatectomy, clearly diagnosed on transrectal echography, may be the cause of persistent irritative urinary symptoms. Treatment can be instituted by echo-guided aspiration of the fluid with simultaneous injection of a potent antibiotic, resulting in probable immediate relief.

Aged↗
PubMed1993

The adrenal chromaffin granule: a model for large dense core vesicles of endocrine and nervous tissue.

More than 25 years have elapsed since R. E. Coupland made his classic observations on the ultrastructure of chromaffin granules, on the histochemical differentiation of noradrenaline and adrenaline storage granules and on their release by exocytosis. This essay attempts to demonstrate that subsequent studies on the biochemistry of chromaffin granules have yielded analytical and functional data relevant for all large dense core vesicles of endocrine and nervous tissue.

Adrenal Medulla↗
PubMed1992

Differential subcellular distribution of PC1, PC2 and furin in bovine adrenal medulla and secretion of PC1 and PC2 from this tissue.

The subcellular distribution of PC1, PC2 and furin was determined in bovine adrenal medulla by immunoblotting of fractions obtained by density gradient centrifugation. PC1 and PC2 were found to be confined to chromaffin granules whereas furin (C-terminal-peptide) was absent from these organelles. Stimulation of bovine adrenal medulla by carbamoylcholine chloride induced the secretion of PC1 and PC2. The secreted enzymes had the same molecular size as PC1 and PC2 present in chromaffin granules.

Adrenal Medulla↗
PubMed1992

Evidence for polynuclear aggregates of ferric daunomycin. A Mössbauer, EPR, X-ray absorption spectroscopy and magnetic susceptibility study.

The interaction of the antitumor agent daunomycin (DN) with ferric iron has been analysed by Mössbauer spectroscopy, EPR, extended X-ray absorption fine structure (EXAFS), and magnetic susceptibility measurements. In contrast to literature data, at millimolar iron and anthracycline concentrations no solitary Fe(DN)3 complexes are formed in appreciable amounts. The Mössbauer spectroscopic analysis revealed severe dependencies on temperature, on the preparation procedure, the time allowed for equilibration, and on the metal/ligand ratio. The Mössbauer spectra exhibit two components: a broad magnetic sextet and a quadrupole doublet at an Fe/DN molar ratio of 1:3 and exclusively a doublet at a molar ratio of 1:20, indicating an equilibrium of these two spectral components. The EPR spectra are dominated by a signal at g(eff) = 2. Double integration of the EPR signals enabled the determination of their spin density and a correlation between EPR and Mössbauer spectra. The Mössbauer sextet species is EPR invisible and corresponds to magnetically ordered polynuclear aggregates with high magnetic anisotropy. EXAFS and susceptibility measurements provide additional evidence for the formation of polynuclear aggregates of ferric daunomycin. The quadrupole doublet species in the Mössbauer spectra correlates with the g = 2 signal in EPR. This species is also related to a magnetically ordered system, exhibiting, however, superparamagnetic behavior due to less magnetic anisotropy. Since daunomycin forms dimers in aqueous solution at millimolar concentrations, we conclude that the cooperative phenomena observed in EPR and Mössbauer spectra are a consequence of its stacking effects.

Daunorubicin↗
PubMed1992

Immunological characterization of the endoproteases PC1 and PC2 in adrenal chromaffin granules and in the pituitary gland.

Specific antisera against synthetic fragment of the endoproteases, PC1 and PC2, were used to characterize these proteins. In one-dimensional immunoblots these antisera labelled components of 85 kDa for PC1 and of 70 kDa for PC2 in purified bovine chromaffin granules and anterior and posterior pituitary of ox and rat. In membranes of bovine chromaffin granules glycoprotein H was identified as the major PC2 immunoreactive spot. A major part of these endoproteases appeared membrane bound.

Adrenal Medulla↗
PubMed1992

Temporal lobe epilepsy of the rat: differential expression of mRNAs of chromogranin B, secretogranin II, synaptin/synaptophysin and p65 in subfield of the hippocampus.

We have investigated by in situ hybridization changes in the content of mRNAs encoding for chromogranin B, secretogranin II, synaptin/synaptophysin and p65 after kainic acid-induced seizures and pentylenetetrazol kindling. Kainic acid seizures resulted in marked but transient increases in secretogranin II mRNA concentrations in the granule cell layer and throughout the pyramidal cell layers of the hippocampus (by 100-500%) as well as in various areas of the cerebral cortex (by up to 900%) and the thalamus (up to 300%) 12 h after injection of the toxin. Chromogranin B mRNA concentrations were persistently increased in granule cells (but not in pyramidal cells) of the hippocampus (suprapyramidal blade, 450%) and in cortical areas (250%) at all time intervals after kainic acid injection (12 h to 60 days). Accordingly chromogranin B immunoreactivity was enhanced in the terminal field of mossy fibers and in the inner part of the molecular layer 30 days after kainic acid. Secretogranin II immunoreactivity was also markedly increased in CA1, the paraventricular thalamic nucleus and in the central amygdala. In rats kindled with pentylenetetrazol only chromogranin B (by 200%) but not secretogranin II mRNA was increased in dentate granule cells. In contrast to the mRNAs of these secretory proteins concentrations of mRNAs encoding synaptin/synaptophysin and p65, two membrane proteins of synaptic vesicles, were not altered in any of these brain structures. These data demonstrate that in brain the biosynthesis of chromogranin B and secretogranin II is regulated like that of neuropeptides which is consistent with a role of these secretory polypeptides as precursors of functional peptides. Activation of neurons induces an increased synthesis of neuropeptides but not a concomitant synthesis of membrane proteins of synaptic vesicle. This might lead to an increased quantal content available for transmission.

Animals↗
PubMed1992

Synaptic pathology in Alzheimer's disease: immunological data for markers of synaptic and large dense-core vesicles.

We have analysed several markers for small synaptic vesicles (synaptin-synaptophysin, p65 and SV2) and large dense-core vesicles (chromogranin A, secretogranin II/chromogranin C) in the brains of patients with Alzheimer's disease, and normal controls by immunoblotting and immunohistochemistry. In comparison to age-matched controls the levels of all three synaptic vesicle markers were decreased in temporal cortex of Alzheimer patients. On the other hand, the levels of chromogranin A were increased, and those of secretogranin II lowered. This resulted in a significant increase of the ratios of chromogranin A to synaptophysin, p65 or SV2 and of that for chromogranin A to secretogranin II. These increases were significantly correlated to clinical severity of dementia and extent of neuropathological changes. By immunohistochemistry a high percentage of senile plaques was found to contain chromogranin A-reactive dystrophic neurites, whereas synaptophysin reactivity within plaques was rare. These results indicate that the number of synaptic vesicles is lowered in Alzheimer's disease, and that one component of large dense-core vesicles, i.e. chromogranin A, is elevated. We, thus, suggest that in Alzheimer's brain distinct changes occur for both types of synaptic organelles.

Aged↗
PubMed1992

In situ hybridization: mRNA levels of secretogranin II, neuropeptides and carboxypeptidase H in brains of salt-loaded and Brattleboro rats.

In situ hybridization was used to study the mRNA levels for vasopressin, galanin, secretogranin II and carboxypeptidase H in salt-loaded and Brattleboro rats. These animals represent an in vivo model for the chronic stimulation of the hypothalamo-neurohypophyseal neurons. As shown by immunelectron microscopy secretogranin II is co-stored with vasopressin in these neurons. In salt-loaded rats the levels of mRNA for vasopressin, galanin and secretogranin II are increased in the paraventricular and supraoptic nuclei. Analogous changes were observed for Brattleboro rats with the exception of the vasopressin message which was decreased in these animals. The secretogranin II message was also increased in neurons which do not contain the vasopressin mRNA, i.e. in magnocellular neurons of the lateral hypothalamus and in the subfornical organ. Carboxypeptidase H message was also found in the paraventricular and supraoptic nuclei and in the subfornical organ; however, in both models the changes in mRNA in these nuclei were much lower than those observed for the secretory peptides or non-existent. We conclude that chronic stimulation of vasopressin neurons leads to a concomitant up-regulation of the biosynthesis of neuropeptides and secretogranin II. We suggest that the secretogranin II message might be a useful general marker for identifying chronically stimulated neurons.

Animals↗
PubMed1992

Erythrocyte pyruvate kinase deficiency: relations of residual enzyme activity, altered regulation of defective enzymes and concentrations of high-energy phosphates with the severity of clinical manifestation.

The defective enzymes of 54 patients with pyruvate kinase (PK) deficiency were characterized according to the recommendations of the International Committee for Standardization in Haematology (ICSH). The erythrocyte PK activity in whole blood was calculated considering the 16-fold higher activity of the reticulocyte enzyme (AR) compared to the erythrocyte enzyme (AE). The following parameters turned out to give a good correlation to the degree of haemolytic anaemia and can therefore serve as a prognostic tool: All patients with a severe course of the disease had residual erythrocyte PK activities less than 33% of the normal enzymes (percentage activity), and patients with mild haemolytic anaemia exhibited residual activity values below and above this threshold value. Studies of enzyme cooperative showed that positive cooperative or mixed cooperative phosphoenolpyruvate (PEP) binding with a predominant positive cooperative part appeared in all cases with a mild clinical course, and about one-third of the severe ones. Negative cooperativity or mixed cooperativity with predominant negative cooperative part was observed only with severe haemolytic anaemia. Furthermore, the determination of glucose-6-phosphate (G-6-P) turned out to be a good prognostic criterion, i.e. all patients with mild clinical course exhibited G-6-P-concentrations lower than 0.11 mumol/l red blood cells. In the case of patients with severe haemolytic anaemia, about 80% showed values higher than 0.11 mumol/l RBC.

2,3-Diphosphoglycerate↗
PubMed1992

Secretogranin II expression in Ewing's sarcomas and primitive neuroectodermal tumors.

Production of chromogranins, the acidic components of the chromaffin granules regarded as specific neuroendocrine markers, was analyzed by immunocytochemistry and hybridization (Northern blotting and in situ hybridization) in primary lesions and cell lines of Ewing's sarcomas, primitive neuroectodermal tumors (PNETs), and neuroblastomas. Antibodies and probes specific for chromogranin A (CgA), chromogranin B (CgB), and secretogranin II (SgII) were used. Ewing's sarcomas and PNETs, unlike neuroblastomas, were negative for CgA and CgB. Two primary Ewing's sarcomas, one primary PNET (an Askin tumor), and one PNET cell line (TC32) were found to strongly express the SgII gene, as shown by the presence of specific mRNA. This result supports the hypothesis that some Ewing's sarcomas represent a most primitive form of neuroectodermal tumor; in addition, it indicates a diagnostic role of SgII in cases of Ewing's sarcomas and PNETs.

Adolescent↗
PubMed1991

Synaptin/synaptophysin, p65 and SV2: their presence in adrenal chromaffin granules and sympathetic large dense core vesicles.

The subcellular distribution of three proteins of synaptic vesicles (synaptin/synaptophysin, p65 and SV2) was determined in bovine adrenal medulla and sympathetic nerve axons. In adrenals most p65 and SV2 is confined to chromaffin granules. Part of synaptin/synaptophysin is apparently also present in these organelles, but a considerable portion is found in a light vesicle which does not contain significant concentrations of typical markers of chromaffin granules (cytochrome b-561, dopamine beta-hydroxylase or the amine carrier). An analogous finding was obtained for sympathetic axons. The large dense core vesicles contain most p65 and also SV2 but only a smaller portion of synaptin/synaptophysin. A lighter vesicle containing this latter antigen and some SV2 has also been found. These results establish that in adrenal medulla and sympathetic axons three typical antigens of synaptic vesicles are not restricted to light vesicles. Apparently, a varying part of these antigens is found in chromaffin granules and large dense core vesicles. On the other hand, the light vesicles do not contain significant concentrations of functional antigens of chromaffin granules. Thus, the biogenesis of small presynaptic vesicles which contain all three antigens as well as functional components like the amine carrier is likely to involve considerable membrane sorting.

Adrenal Medulla↗