Niels A. Thorn

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H EIDENHAIN (I) first demonstrated that the concentration of inorganic salts in the submaxillary saliva of dogs varies in proportion to the secretory rate. Gregersen and Ingalls (2) showed that the concentration of sodium increases with increasing rates of secretion, whereas the concentration of potassium is independent of salivary flow. This finding has(More)
In isolated nerve terminals from ox neurohypophyses the following concentrations of polyamines [pmol (microgram protein)-1 (mean +/- SEM)] were found: spermine: 2.07 +/- 0.14 (n = 3), spermidine: 0.22 +/- 0.01 (n = 4), putrescine: 0.20 +/- 0.01 (n = 4). In secretory granules isolated from the same tissue, the concentrations were: spermine: 0.57 +/- 0.02 (n(More)
Freeze cleaving electron microscopy has shown that fusion of isolated secretory vesicles from bovine neurohypophyses was induced by Ca2+ in micromolar concentrations. Mg2+ and Sr2+ were ineffective. Mg2+ inhibited Ca2+-induced fusion. In suspensions containing secretory vesicles as well as sheets of cell membrane, release of vasopressin parallel to(More)
A procedure is described for the isolation of secretory vesicles from bovine neurohypophyses by differential centrifugation followed by density gradient centrifugation on iso-osmolal gradients of percoll/sucrose. Only negligible contamination of the secretory vesicle fraction with markers for mitochondria, microsomes and plasma membranes could be detected.(More)
Isolated nerve endings (neurosecretosomes) from ox neurohypophyses took up L-[14C]ascorbic acid by a process or processes which showed energy dependence and which could be inhibited by unlabelled ascorbic acid in micromolar concentrations and by isoascorbic acid in millimolar concentrations, whereas dehydroascorbic acid only inhibited in concentrations of(More)
Several amidated biologically active peptides such as pancreastatin, thyrotropin-releasing hormone, pancreatic polypeptide and amylin are produced in endocrine pancreatic tissue which contains the enzyme necessary for their final processing, i.e. peptidylglycine alpha-amidating mono-oxygenase (EC The enzyme needs ascorbic acid for activity as(More)