ISSN:
1432-1912
Keywords:
Adrenal Medulla
;
Chromogranin
;
Catecholamines
;
Synthesis
;
Secretion
Source:
Springer Online Journal Archives 1860-2000
Topics:
Medicine
Notes:
Summary 1. 3H-leucine and3H-tyrosine were added to the perfusion medium of isolated bovine adrenal glands in order to study the synthesis and secretion of radioactively labelled catecholamines and proteins. 2. Various times after the injection of the labelled amino acids the soluble proteins of the microsomal fraction were isolated and subjected to polyacrylamide gel electrophoresis in three different buffer systems. The distribution of protein-bound radioactivity within the gels was determined. Most of the label was found to be confined to proteins which behaved like the specific soluble proteins of chromaffin granules, i.e. the chromogranins. 3. Stimulation of the adrenal gland with carbachol induced a release of catechol-amines, protein, and protein-bound radioactivity. In the absence of Ca2+ the secretion of all these components was abolished. The highest specific radioactivity of the proteins secreted upon stimulation was reached 4 h after the injection of the labelled precursors. The labelled proteins, secreted upon stimulation, could be identified as chromogranins. 4. Carbachol induced the release of highly labelled catecholamines after the injection of3H-tyrosine. The highest specific radioactivity of these catecholamines was already observed at the first stimulation with carbachol i.e. 30 min after3H-tyrosine. 5. These results demonstrate that in isolated bovine adrenal glands radioactively labelled chromogranins and catecholamines can be synthesised and can be secreted upon stimulation with carbachol.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF00998580
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