Isolation of chromaffin granules.
Adrenal medullary chromaffin granules (dense core secretory vesicles) have been a valuable model system for the study of the proteins and membrane components involved in the process of exocytosis. Because of the abundance of chromaffin granules in a readily available tissue source, bovine adrenal medullae, and their unique sedimentation properties, it is possible to obtain large quantities of highly purified granules and granule membranes in a short period of time. Two protocols are presented here for the isolation of chromaffin granules: a basic protocol based on differential centrifugation in an iso-osmotic medium that yields intact chromaffin granules, and an alternate protocol based on sedimentation through a density step gradient that provides a greater yield of more highly purified chromaffin granules. Since in the latter case the granules cannot be returned to a medium of physiological osmolarity without lysis after purification on the step gradient, the alternate protocol is more useful to obtain the granule membranes or contents for further study.
Creutz
Carl E
CE
Department of Pharmacology, University of Virginia, Charlottesville, Virginia, USA.
D000313:Adrenal Medulla / Q000473:pathology*; D000818:Animals; D001671:Biochemistry / Q000379:methods; D002417:Cattle; D002458:Cell Fractionation; D002462:Cell Membrane / Q000378:metabolism; D002837:Chromaffin Granules / Q000378:metabolism* / Q000473:pathology; D005089:Exocytosis / Q000502:physiology; D009994:Osmolar Concentration