Comparative gastrointestinal effects of mycophenolate mofetil capsules and enteric-coated tablets of sodium-mycophenolic acid in beagle dogs

YCOPHENOLATE MOFETIL (MMF, CellCept) is an important and effective clinical immunosuppressive agent for the prevention of transplant rejection. Use of MMF has reduced the frequency and severity of acute rejection and has improved graft survival in both cardiac and renal transplants. 1 MMF is the prodrug of the active ingredient mycophenolic acid (MPA), which noncompetitively inhibits inosine monophosphate dehydrogenase (IMPDH), the rate-limiting enzyme in de novo synthesis of guanosine nucleotides. In contrast to other cell types that can utilize the purine salvage pathway, T cells and B cells generate purine nucleotides for DNA replication almost exclusively via the IMPDH pathway. Furthermore, of the two isoforms of IMPDH (type I and type II), MPA is five times more potent against type II, the isoform preferentially expressed in activated lymphocytes. Therefore, MPA has significantly more potent cytostatic effects on lymphocytes