Incisor degeneration in rats induced by vascular endothelial growth factor/fibroblast growth factor receptor tyrosine kinase inhibition

Toxicol Pathol. 2010 Feb;38(2):267-79. doi: 10.1177/0192623309357950. Epub 2010 Jan 25.

Abstract

BMS-645737, an inhibitor of vascular endothelial growth factor (VEGF) receptor-2 and fibroblast growth factor (FGF) receptor-1, has anti-angiogenic activity and was evaluated in nonclinical studies as a treatment for cancer. This article characterizes the BMS-645737-induced clinical, gross, and histologic lesions of incisor teeth in Sprague-Dawley (SD) rats. Rats received 0 800 mg/kg BMS-645737 in a single-dose study or consecutive daily doses of 0 20 mg/kg/day in a 1-month study. The reversibility of these effects was assessed in the 1-month study. White discoloration and fracture of incisors were observed clinically and grossly in the 1-month study. In both studies, dose-dependent histopathologic lesions of incisors were degeneration and/or necrosis of odontoblasts and ameloblasts; decreased mineralization of dentin; inflammation and necrosis of the dental pulp; and edema, congestion, and hemorrhage in the pulp and periodontal tissue adjacent to the enamel organ. Partial recovery was observed at lower doses after a two-week dose-free period in the one-month study. Drug-induced incisor lesions were considered to be related to the pharmacologic inhibitory effects on VEGF and FGF signaling, that is, inhibition of growth and maintenance of small-diameter vessels that support the formation of dentin and enamel in growing teeth and/or to perturbances of function of odontoblasts and ameloblasts or their precursors.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Angiogenesis Inhibitors / toxicity*
  • Animals
  • Dentin / metabolism
  • Dose-Response Relationship, Drug
  • Female
  • Incisor / drug effects*
  • Incisor / pathology
  • Male
  • Necrosis
  • Odontoblasts / drug effects
  • Odontoblasts / metabolism
  • Protein Kinase Inhibitors / toxicity*
  • Pyrroles / toxicity*
  • Rats
  • Rats, Sprague-Dawley
  • Receptor, Fibroblast Growth Factor, Type 1 / antagonists & inhibitors*
  • Toxicity Tests
  • Triazines / toxicity*
  • Vascular Endothelial Growth Factor Receptor-2 / antagonists & inhibitors*

Substances

  • 5-isopropyl-6-(5-methyl-1,3,4-oxadiazol-2-yl)-N-(2-methyl-1H-pyrrolo(2,3-b)pyridin-5-yl)pyrrolo(2,1-f)(1,2,4)triazin-4-amine
  • Angiogenesis Inhibitors
  • Protein Kinase Inhibitors
  • Pyrroles
  • Triazines
  • Receptor, Fibroblast Growth Factor, Type 1
  • Vascular Endothelial Growth Factor Receptor-2