Anti-myosin stains chromaffin cells.

The presence in fixed chromaffin cells of antigenic sites for a myosin antibody was demonstrated using immunofluorescence techniques. Tests on viable cells showed that at least some of the antigenic sites seem to be localized on or close to the cell surface and explained the cell agglutination that occurred with the addition of the myosin antibody to cells isolated by a method described in this paper.     

Morphological aspects of chemically stimulated bovine chromaffin cells

Summary Isolated bovine chromaffin cells were chemically stimulated. The resulting appearance of local changes in membrane structure were compared with the integration of granular proteins into the cell membrane as seen after binding of fluorescence labeled anti-dopamine--hydroxylase. Protuberances of the cell membrane which can be perceived by Nomarski contrast optics are largely congruent with local tracer accumulations at the cell surface.     

Argyrophilic cells of the dog pancreas following different silver stains

Riassunto L'esame comparativo dei risultati ottenuti dopo impregnazione argentica di sezioni di pancreas di cane con i metodi di Davenport (modificato daHellerström edHellman) e di Bodian ha rivelato notevoli diversità. L'indagine su sezioni seriate fa ritenere che le cellule argirofile nei confronti di un metodo non lo siano nei confronti dell'altro. I riflessi sulla citologia endocrina del pancreas di cane e sul significato delle differenti metodiche argentofile sono brevemente discussi.     

Giant granules in adrenaline-secreting chromaffin cells of lizard adrenal glands after metyrapone administration

Summary Secretory granules of extraordinary size, some of them bigger than the cell nucleus, abound in the adrenaline cells of lizard adrenals after metyrapone injections during 7 days. In these granules, the bounding membrane is studded with ribosomes, and the core is formed by rounded small subunits. Some granules of this type are also found in noradrenaline cells. They may represent an exceptionally increased elaboration and storage of adrenaline, induced by metyrapone probably through its action on steroidogenic tissue.This research forms part of project No. 31.26.S1-1154 supported by the Consejo Nacional de Investigaciones Científícas y Tecnológicas.     

Differential scanning calorimetry of chromaffin granule membranes

Summary Differential scanning calorimetry thermograms of native chromaffin granule membranes exhibit several peaks in the 15–35°C region. Extraction of cholesterol increases the size of the melting peaks. Addition of Ca²⁺ ions does not seem to influence the lipid transitions.This research was supported in part by a grant from the United States-Israel Binational Science Foundation (BSF), Jerusalem, Israel. A.S. acknowledges partial support for this research from a National Science Foundation Grant PCM 04079, and from National Institutes of Health grants CA 08748 ans CA 18759.     

A novel pattern of fast calcium oscillations points to calcium and electrical activity cross-talk in rat chromaffin cells

Slow oscillations of cytosolic calcium ion concentration – – typically originate from release by intracellular stores, but in some cell types can be triggered and sustained by Ca²⁺ influx as well. In this study we simultaneously monitored changes in and in the electrical activity of the cell membrane by combining indo-1 and patch-clamp measurements in single rat chromaffin cells. By this approach we observed a novel type of spontaneous oscillations, much faster than those previously described in these cells. These oscillations are triggered and sustained by complex electrical activity (slow action potentials and spike bursts), require Ca²⁺ influx and do not involve release from intracellular stores. The possible physiological implications of this new pathway of intracellular signalling are discussed.Received 30 July 2004; received after revision 14 October 2004; accepted 1 November 2004     

Differential scanning calorimetry of chromaffin granule membranes.

Differential scanning calorimetry thermograms of native chromaffin granule membranes exhibit several peaks in the 15-35 degrees C region. Extraction of cholesterol increases the size of the melting peaks. Addition of Ca2+ ions does not seem to influence the lipid transitions.     

On the origin of adenosine triphosphate in chromaffin granules

Résumé Les granules chromaffines contiennent de fortes quantités de nucléotides (ATP). L'origine de cet ATP est inconnue, mais il a été admis implicitement que la réaction ADPATP+AMP est catalysée par l'enzyme adénylate kinase. Nous avons recherché la présence de cet enzyme dans des granules isolés en gradient de densité de sucrose.     

In vitro interaction of enkephalin with serum and chromaffin granule components

Summary Incubation of radioactively labeled enkephalin with serum components or chromaffin granule components in vitro provided evidence that there are specific constituents which bind enkephalins and may affect their degradation. Evidence for carboxy-terminal degradation was found.This work was supported by the NIH Grants NS-13201 and NS-00201.     

Effect of transmembrane potential on noradrenaline transport in chromaffin granules]

Imposing a transmembrane potential positive with respect to the medium on chromaffin granule ghosts increased the initial rate of the delta pH-induced uptake of noradrenaline, whereas imposing a negative potential decreased this rate. The increase of the uptake rate was proportional to the potential. The ATP-induced uptake of noradrenaline was also sensitive to the potential since imposing a transient negative potential onto the positive potential generated by the membrane ATPase induced a latency in this transport.     

Effect of aldosterone,glucagon and growth hormone on the catechol amine content and the evolution of chromaffin hyperplasia in guinea-pigs

Résumé La variation du taux des catécholamines (adrénaline et noradrénaline) et les modifications histologiques ont été étudiés après administration d'aldostérone, de glucagon et d'hormone de croissance sur l'hyperplasie médullo-chromaffine provoquée chez des cobayes par l'stradiol.

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The authors thank CIBA AG, Basle, for kindly supplying the Aldocorten used in these experiments.     

Spontaneous fusion between cancer cells and endothelial cells

Endothelial cells line the inside of blood and lymphatic vessels, and cancer cells must cross this barrier, first to gain access to the circulation, and, second, to exit and metastasize. How this occurs is incompletely understood. We now demonstrate that human cancer cells are able to fuse with endothelial cells to form hybrid cells displaying proteins and chromosomal markers characteristic of both parent cells. The hybrid cells are viable and capable of undergoing mitosis. Fusions between cancer cells and endothelial cells were shown to occur both in vitro, in co-cultures of human breast cancer cells and endothelial cells, and in vivo, following intravascular dissemination of human breast cancer cells in nude mice. These observations demonstrate a new type of cancer-endothelial cell interaction that may be of fundamental importance to the process of metastasis.Received 10 May 2004; received after revision 21 June 2004; accepted 2 July 2004     

Eradication of lymphoma cells with allogeneic immune peritoneal cells

Zusammenfassung DBA/2 Mäuse wurden nach Injektionen mit SL2 Zellen mit allogenen, immunen und hyperimmunen Exsudat-Zellen aus dem Peritonealraum behandelt. Diese Behandlung ergab eine Eliminierung von 2×10⁶ SL2 Zellen.