FK1706, a novel non-immunosuppressive immunophilin ligand, modifies the course of painful diabetic neuropathy

Neuropharmacology. 2008 Dec;55(7):1226-30. doi: 10.1016/j.neuropharm.2008.07.048. Epub 2008 Aug 8.


FK1706, a derivative of FK506, is a non-immunosuppressive immunophilin ligand with significant neurotrophic activity mediated via FKBP-52 and the RAS/RAF/MAPK signaling pathway. Here, we tested the effect of FK1706 on painful diabetic neuropathy in rat model of diabetes induced by streptozotocin (STZ). FK1706 ameliorated mechanical allodynia in this model at doses over 0.32 mg/kg, p.o., even if treatment was initiated after neuropathy was established, and did not affect plasma glucose levels. Furthermore, this improvement continued at least 4 weeks after the last administration. In morphological analysis, FK1706 treatment also restored intraepidermal nerve fiber density in footpad skin to almost normal levels. Gabapentin also improved mechanical allodynia in the same model, but efficacy disappeared the day after administration stopped. Allodynia responses were potentiated by co-administration of both compounds. Thus, FK1706 ameliorated painful diabetic neuropathy via a different mechanism from gabapentin and improved morphological outcomes, indicating that FK1706 improves painful diabetic neuropathy by modifying the underlying disease pathology.

Publication types

  • Comparative Study

MeSH terms

  • Amines / pharmacology
  • Analgesics / pharmacology
  • Animals
  • Cyclohexanecarboxylic Acids / pharmacology
  • Diabetes Mellitus, Experimental / complications
  • Diabetic Neuropathies / drug therapy*
  • Diabetic Neuropathies / psychology
  • Dose-Response Relationship, Drug
  • Gabapentin
  • Immunohistochemistry
  • Immunophilins / chemistry*
  • Ligands
  • Male
  • Pain / drug therapy*
  • Pain / etiology
  • Pain Measurement / drug effects
  • Physical Stimulation
  • Rats
  • Rats, Sprague-Dawley
  • Tacrolimus / analogs & derivatives*
  • Tacrolimus / pharmacology
  • gamma-Aminobutyric Acid / pharmacology


  • Amines
  • Analgesics
  • Cyclohexanecarboxylic Acids
  • FK1706
  • Ligands
  • gamma-Aminobutyric Acid
  • Gabapentin
  • Immunophilins
  • Tacrolimus