Sympathetic axons and nerve terminals: the protein composition of small and large dense-core and of a third type of vesicles.
Homogenates of bovine splenic nerve and of vas deferens were subjected to differential and density gradient centrifugation to investigate their noradrenaline-storing organelles. The subcellular fractions obtained were analysed by immunoblotting in order to define the presence of various antigens in small dense-core and large dense-core vesicles. In both large granule and microsomal fractions from splenic nerve only one type of noradrenaline-storing vesicle was found, which represents the large dense-core vesicles. These organelles contained chromogranin A, chromogranin B, cytochrome b-561, carboxypeptidase H, glycoprotein II, glycoprotein III, dopamine beta-hydroxylase and the monoamine carrier which are also present in adrenal chromaffin granules. The subcellular distribution of synaptin/synatophysin was more complex since this protein was apparently present in two organelles: in a light vesicle which did not contain significant amounts of antigens found in large dense-core vesicles (dopamine beta-hydroxylase, cytochrome b-561 and the monoamine carrier) and in the dense fractions of the gradient, possibly within large dense-core vesicles. In the microsomal gradient from vas deferens several markers (catecholamines, synaptin/synaptophysin and dopamine beta-hydroxylase) were found in a bimodal distribution, which is consistent with their presence in small and large dense-core vesicles. When the larger granules were removed with higher centrifugation speed a microsomal fraction containing only light vesicles was obtained. After gradient centrifugation of this fraction several components (catecholamines, dopamine beta-hydroxylase, cytochrome b-561, the monoamine carrier and synaptin/synaptophysin) were concentrated in a peak at low density; apparently only small dense-core vesicles were now present.(ABSTRACT TRUNCATED AT 250 WORDS)
Schwarzenbrunner
U
U
Department of Pharmacology, University of Innsbruck, Austria.
Schmidle
T
T
Obendorf
D
D
Scherman
D
D
Hook
V
V
Fischer-Colbrie
R
R
Winkler
H
H
D000818:Animals; D001369:Axons / Q000378:metabolism*; D002395:Catecholamines / Q000378:metabolism; D002417:Cattle; D002499:Centrifugation, Density Gradient; D004299:Dopamine beta-Hydroxylase / Q000378:metabolism; D066298:In Vitro Techniques; D008297:Male; D008565:Membrane Proteins / Q000378:metabolism; D009411:Nerve Endings / Q000378:metabolism*; D009419:Nerve Tissue Proteins / Q000276:immunology / Q000378:metabolism*; D013154:Spleen / Q000294:innervation; D013347:Subcellular Fractions / Q000378:metabolism; D013564:Sympathetic Nervous System / Q000166:cytology / Q000378:metabolism*; D013572:Synaptic Vesicles / Q000378:metabolism; D016708:Synaptophysin; D014649:Vas Deferens / Q000378:metabolism / Q000648:ultrastructure
D002395:Catecholamines; D008565:Membrane Proteins; D009419:Nerve Tissue Proteins; D016708:Synaptophysin; C030625:synaptin; D004299:Dopamine beta-Hydroxylase