Paracetamol (acetaminophen) attenuates in vitro mast cell and peripheral blood mononucleocyte cell histamine release induced by N-acetylcysteine.
BACKGROUND
The treatment of acute paracetamol (acetaminophen) poisoning with N-acetylcysteine (NAC) is frequently complicated by an anaphylactoid reaction to the antidote. The mechanism that underlies this reaction is unclear. We used the human mast cell line 1 (HMC-1) and human peripheral blood mononucleocytes (PBMCs) to investigate the effects of NAC and paracetamol on histamine secretion in vitro.


METHODS
HMC-1 and human PBMCs were incubated in the presence of increasing concentrations of NAC +/- paracetamol. Cell viability was determined by the Trypan Blue Assay, and histamine secretion was measured by ELISA.


RESULTS
NAC was toxic to HMC-1 cells at 100 mg/mL and to PBMCs at 67 mg/mL. NAC increased HMC-1 and PBMC histamine secretion at concentrations of NAC from 20 to 50 mg/mL and 2.5 to 100 mg/mL, respectively. NAC-induced histamine secretion by both cell types was reduced by co-incubation with 2.5 mg/mL of paracetamol.


CONCLUSIONS
Paracetamol (acetaminophen) is capable of modifying histamine secretion in vitro. This may explain the clinical observation of a lower incidence of adverse reactions to NAC in vivo when higher concentrations of paracetamol are present than when paracetamol concentrations are low. Paracetamol (acetaminophen) attenuates in vitro mast cell and PBMC cell histamine release induced by NAC.
Coulson
James
J
School of Medicine, University Hospital of Wales, Cardiff University, Heath Park, Cardiff, UK. jzm6jmc@doctors.org.uk
Thompson
John Paul
JP
D000082:Acetaminophen / Q000008:administration & dosage / Q000494:pharmacology*; D000111:Acetylcysteine / Q000008:administration & dosage / Q000633:toxicity*; D018712:Analgesics, Non-Narcotic / Q000008:administration & dosage / Q000494:pharmacology*; D000931:Antidotes / Q000633:toxicity*; D002460:Cell Line; D002470:Cell Survival / Q000187:drug effects; D002478:Cells, Cultured; D004305:Dose-Response Relationship, Drug; D004797:Enzyme-Linked Immunosorbent Assay; D006636:Histamine Release / Q000187:drug effects; D006801:Humans; D007963:Leukocytes, Mononuclear / Q000187:drug effects / Q000378:metabolism; D008297:Male; D008407:Mast Cells / Q000187:drug effects / Q000378:metabolism; D014343:Trypan Blue
D018712:Analgesics, Non-Narcotic; D000931:Antidotes; D000082:Acetaminophen; D014343:Trypan Blue; D000111:Acetylcysteine