Inhibition of complement components C3 and C4 by cadralazine and its active metabolite

Eur J Clin Pharmacol. 1991;40(3):261-5. doi: 10.1007/BF00315206.

Abstract

The effect of cadralazine and its active metabolite CGP 22639 on the covalent binding reaction of C4 and C3 has been studied. Trypsin-Sepharose was used to activate radio-labelled C3 and C4 and binding of the radio-labelled protein to the trypsin-Sepharose was measured. Cadralazine inhibited 50% of the binding of C3 and C4 at concentrations of 19 mmol/l and 15 mmol/l, respectively. Its active metabolite was more potent and inhibited 50% of the C3 and C4 binding at concentrations of 8 and 3.5 mmol/l, respectively. These concentrations are much higher than those found in plasma during therapy. This is consistent with the clinical observation that in patients with normal kidney function cadralazine is not an inducer of SLE.

Publication types

  • Comparative Study

MeSH terms

  • Antihypertensive Agents / metabolism
  • Antihypertensive Agents / pharmacology*
  • Complement C3 / antagonists & inhibitors*
  • Complement C3 / metabolism
  • Complement C4 / antagonists & inhibitors*
  • Complement C4 / metabolism
  • Dihydralazine / pharmacology
  • Humans
  • Hydralazine / pharmacology
  • Hydroxylamine
  • Hydroxylamines / pharmacology
  • Procainamide / pharmacology
  • Pyridazines / metabolism
  • Pyridazines / pharmacology*
  • Vasodilator Agents / pharmacology*

Substances

  • Antihypertensive Agents
  • Complement C3
  • Complement C4
  • Hydroxylamines
  • Pyridazines
  • Vasodilator Agents
  • Hydralazine
  • Hydroxylamine
  • ISF 2405
  • cadralazine
  • Procainamide
  • Dihydralazine