Expression of vascular endothelial growth factor and its receptors in the cochlea of various experimental animals.
CONCLUSIONS
The results of this study indicate that vascular endothelial growth factor (VEGF) may be an important regulator of the vascular network of the inner ear and suggest that the VEGF signalling pathway may play a role in pathophysiologic conditions.


OBJECTIVE
In order to clarify the role of vascular growth factor in the modulation of the vascular network of the cochlea, we studied the expression of VEGF and its receptors-fms-like tyrosine kinase (Flt-1) and foetal liver kinase (Flk-1)-in the inner ear of 3-month-old rodents of different species: C57BL/6J mice, Wistar albino rats and Hartley albino guinea pigs.


METHODS
Qualitative immunohistochemical studies were performed by using specific antibodies to VEGF and its receptors on paraffin sections of the cochlea. The expression levels of VEGF and its receptors were quantified by means of Western blot analysis of cochlea protein extracts.


RESULTS
We demonstrated that VEGF and its receptors are expressed in the cochlea and described their distribution in the inner ear. In particular, VEGF and Flt-1 are present at the level of the modiolus, spiral ganglion, spiral ligament, basilar membrane, supporting cells, outer and inner hair cells and stria vascularis. Flk-1 was less strongly expressed in the cochlea and was not detected in the organ of Corti.
Picciotti
Pasqualina M
PM
Institute of Otorhinolaryngology, School of Medicine, Catholic University of the Sacred Heart, L.go A. Gemelli 8, 00168 Rome, Italy. pmpicciotti@rm.unicatt.it
Torsello
Angela
A
Cantore
Italo
I
Stigliano
Egidio
E
Paludetti
Gaetano
G
Wolf
Federica I
FI
D000818:Animals; D017209:Apoptosis / Q000502:physiology; D002455:Cell Division / Q000502:physiology; D002465:Cell Movement / Q000502:physiology; D003051:Cochlea / Q000098:blood supply*; D007758:Ear, Inner / Q000098:blood supply; D004730:Endothelium, Vascular / Q000502:physiology; D006168:Guinea Pigs; D051379:Mice; D008810:Mice, Inbred C57BL; D018919:Neovascularization, Physiologic / Q000502:physiology; D051381:Rats; D017208:Rats, Wistar; D040262:Receptors, Vascular Endothelial Growth Factor / Q000502:physiology*; D015398:Signal Transduction / Q000502:physiology*; D013045:Species Specificity; D042461:Vascular Endothelial Growth Factor A / Q000502:physiology*; D040281:Vascular Endothelial Growth Factor Receptor-1 / Q000502:physiology; D040301:Vascular Endothelial Growth Factor Receptor-2 / Q000502:physiology; D014664:Vasodilation / Q000502:physiology
D042461:Vascular Endothelial Growth Factor A; D040262:Receptors, Vascular Endothelial Growth Factor; D040281:Vascular Endothelial Growth Factor Receptor-1; D040301:Vascular Endothelial Growth Factor Receptor-2