A preferential pole for exocytosis in cultured chromaffin cells revealed by confocal microscopy.
Histological studies suggest that adrenal medulla chromaffin cells in situ are polarised, but functional evidence is lacking. We present here the first demonstration for polarisation of exocytosis in isolated, spherical, bovine chromaffin cells. Cells were stimulated with 70 mM K(+) to cause a marked enhancement of catecholamine release, monitored amperometrically. FM1-43 and dopamine beta-hydroxylase antibodies provided fluorescence confocal pictures that were 2-3-fold more intense in the bottom of the cells, as compared to equatorial or apex planes. This suggests that the solid phase to which the cell attaches serves as a 'trophic' signal for the polarisation of its secretory apparatus.
Cuchillo-Ibáñez
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Departamento de Farmacología, Facultad de Medicina, Universidad Autónoma de Madrid, Arzobispo Morcillo 4, 28029, Madrid, Spain.
Michelena
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P
Albillos
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García
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AG
D000818:Animals; D000906:Antibodies / Q000378:metabolism; D002417:Cattle; D002478:Cells, Cultured; D019439:Chromaffin Cells / Q000502:physiology*; D004299:Dopamine beta-Hydroxylase / Q000276:immunology; D005089:Exocytosis / Q000502:physiology*; D005456:Fluorescent Dyes / Q000378:metabolism; D018613:Microscopy, Confocal; D011726:Pyridinium Compounds / Q000378:metabolism; D000644:Quaternary Ammonium Compounds / Q000378:metabolism
D000906:Antibodies; C073804:FM1 43; D005456:Fluorescent Dyes; D011726:Pyridinium Compounds; D000644:Quaternary Ammonium Compounds; D004299:Dopamine beta-Hydroxylase