title: Recovery of human basophils after FMLP-stimulated secretion.
abstract: BACKGROUND
  Basophils are circulating, secretory granulocytes that are generally considered to be end-stage cells. In one species of guinea-pigs, basophilic leucocytes have been shown to recover from stimulated secretion in short-term cultures. Similar studies have not been done using human basophils.
  
  
  OBJECTIVE
  The purpose of this study was to examine human basophils in short-term recovery intervals following stimulation of secretion to determine whether visual evidence of recovery occurred.
  
  
  METHODS
  We examined the ultrastructural morphology of early recovery (10 min-6 h) of human basophils following secretion stimulated by formyl-methionyl-leucyl-phenyl-alanine (FMLP). A combined technique for electron microscopy consisted of post-fixation exposure to cationized ferritin and reduced osmium, providing maximum quality images and allowing identification of intracellular spaces/organelles that opened to the cell surface, often out of the plane of section.
  
  
  RESULTS
  The ultrastructural evaluation revealed that control basophils (0 time-6 h) did not undergo regulated secretion or develop the morphologies associated with recovery following secretion. FMLP-stimulated basophils underwent an overlapping continuum of piecemeal degranulation-->anaphylactic degranulation (0 time-1 min), producing vesicle- and granule-free, completely degranulated, viable, mature basophils with polylobed nuclei. The early recovery period (10 min-6 h) following FMLP stimulation was characterized by reconstitution of granules. Morphological mechanisms for granule reconstitution included a mixture of conservation, condensation, and synthetic events.
  
  
  CONCLUSIONS
  Human basophils, like guinea pig basophils, have the potential to recover from regulated secretion.
authors.affiliation: Department of Pathology, Beth Israel Hospital, Boston, MA 02215, USA.
authors.forename: A M
authors.initials: AM
authors.lastname: Dvorak
authors.forename: J A
authors.initials: JA
authors.lastname: Warner
authors.forename: P
authors.initials: P
authors.lastname: Fox
authors.forename: L M
authors.initials: LM
authors.lastname: Lichtenstein
authors.forename: D W
authors.initials: DW
authors.lastname: Macglashan
mesh_terms: D001491:Basophils / Q000187:drug effects / Q000502:physiology / Q000648:ultrastructure*; D015550:Cell Degranulation / Q000502:physiology*; D006632:Histamine / Q000378:metabolism; D006801:Humans; D008854:Microscopy, Electron; D009240:N-Formylmethionine Leucyl-Phenylalanine / Q000494:pharmacology*
chemical_list: D009240:N-Formylmethionine Leucyl-Phenylalanine; D006632:Histamine