title: Spontaneous efflux of platelet alpha-granule components in relation to 14C-norepinephrine in buffers.
abstract: In an investigation of the spontaneous efflux of beta-thromboglobulin (beta-TG), 14C-norepinephrine (14C-NE) and growth stimulating activity (GSA), measured as incorporation of 3H-thymidine in rabbit aortic smooth cells, from platelets resuspended in Ca++- and Mg++-free buffer a continuous increase in 3H-thymidine incorporation was seen during 120 min. There was good stoichiometric parallelism between beta-TG and 14C-NE during the 80 minutes the experiment lasted, indicating that norepinephrine is incorporated in alpha-granules and release by exocytosis.
mesh_terms: D000818:Animals; D001609:Beta-Globulins / Q000378:metabolism*; D001792:Blood Platelets / Q000378:metabolism*; D004261:DNA Replication / Q000187:drug effects; D006133:Growth Substances / Q000378:metabolism* / Q000494:pharmacology; D006801:Humans; D007700:Kinetics; D007770:L-Lactate Dehydrogenase / Q000097:blood; D009131:Muscle, Smooth, Vascular / Q000187:drug effects / Q000502:physiology; D009638:Norepinephrine / Q000097:blood*; D010455:Peptides / Q000378:metabolism* / Q000494:pharmacology; D010974:Platelet Aggregation; D010982:Platelet-Derived Growth Factor; D011817:Rabbits; D001620:beta-Thromboglobulin / Q000378:metabolism*
chemical_list: D001609:Beta-Globulins; D006133:Growth Substances; D010455:Peptides; D010982:Platelet-Derived Growth Factor; D001620:beta-Thromboglobulin; D007770:L-Lactate Dehydrogenase; D009638:Norepinephrine