title: Evidence for injurious effect of cocaethylene in human microvascular endothelial cells.
abstract: BACKGROUND
  Cocaethylene (CE) is a conjugate of cocaine and ethanol that may contribute to the pathogenesis of systemic vascular diseases. This study was conducted to investigate the effect of CE on human microvascular endothelial cells (HMEC-1) in culture.
  
  
  METHODS
  Proliferating and confluent monolayers of HMEC-1 were used for assessing growth kinetics, viability, cytotoxicity, and morphologic/barrier alterations after CE treatment (0-1 mmol/l) for up to 7 days. The Trypan blue exclusion, lactate dehydrogenase (LDH) release assay, manual cell counts, and silver nitrate staining technique were used.
  
  
  RESULTS
  The doubling times of 30.0 and 31.4 h for the 0.5 and 1.0 mmol/l CE-treated HMEC-1, respectively, were significantly longer than the 28.6 h for the control group (p < 0.05). The viabilities of 90.4 +/- 3.8% (control) and 93.1 +/- 1.9% (CE-treated) from the Trypan blue exclusion-staining experiments indicated non-lethality of CE. LDH activities of 173 +/- 33 U/l (control) and 157 +/- 43 U/l (CE-treated) confirmed the absence of CE cytotoxicity. Silver staining results indicated increased monolayer permeability as demonstrated by the formation of intercellular gaps after 1 h of exposure.
  
  
  CONCLUSIONS
  HMEC-1 exposure to CE induced cellular injury that could affect the permeability of small blood vessels. These cellular changes could in part be the pivotal point for studies to explain the edema and inflammation in surrounding tissues of individuals exposed to CE.
authors.affiliation: Division of Clinical Chemistry, Department of Pathology, University of Texas Medical Branch, 301 University Boulevard, Galveston, TX 77555-0551, USA.
authors.forename: Danyel Hermes
authors.initials: DH
authors.lastname: Tacker
authors.forename: Anthony O
authors.initials: AO
authors.lastname: Okorodudu
mesh_terms: D000952:Antigens, Polyomavirus Transforming / Q000378:metabolism; D002196:Capillaries / Q000166:cytology / Q000187:drug effects; D002460:Cell Line; D002463:Cell Membrane Permeability / Q000187:drug effects; D049109:Cell Proliferation / Q000187:drug effects; D002470:Cell Survival / Q000187:drug effects; D003042:Cocaine / Q000031:analogs & derivatives* / Q000378:metabolism / Q000633:toxicity*; D003470:Culture Media; D018765:Dopamine Uptake Inhibitors / Q000378:metabolism / Q000633:toxicity*; D004305:Dose-Response Relationship, Drug; D042783:Endothelial Cells / Q000187:drug effects* / Q000648:ultrastructure; D006801:Humans; D007700:Kinetics; D007770:L-Lactate Dehydrogenase / Q000378:metabolism; D016622:Silver Staining
chemical_list: D000952:Antigens, Polyomavirus Transforming; D003470:Culture Media; D018765:Dopamine Uptake Inhibitors; D007770:L-Lactate Dehydrogenase; C066444:cocaethylene; D003042:Cocaine