[The effect of substance P with insulin-like growth factor-1 on corneal epithelial cell proliferation].
OBJECTIVE
To elucidate the pathogenesis of neuroparalytic keratopathy, we examined the effect of substance P (SP) on corneal epithelial cell proliferation in comparison with that of insulin-like growth factor-1 (IGF-1) in vivo and in vitro.


METHODS
In the in vivo study, the epithelium of rabbit cornea was removed mechanically and treated with eye drops containing SP, IGF-1, SP + IGF-1, or physiological saline as a control. Corneas were excised 48 hours after the removal of the epithelium, labeled with 3H-thymidine, and subjected to autoradiography. An in vitro study was also performed by culturing rabbit corneal epithelial cells in culture medium containing SP with or without IGF-1 and labeling cells with 3H-thymidine for a subsequent autoradiographical study.


RESULTS
In the in vivo study, SP in combination with IGF-1 enhanced the healing of rabbit corneal epithelial defect. 3H-thymidine autoradiography revealed that in both in vivo and in vitro studies, SP + IGF-1 stimulated corneal epithelial cell proliferation, but SP or IGF-1 alone did not.


CONCLUSIONS
These results indicate that SP enhances the stimulatory effect of IGF-1 on corneal epithelial cell proliferation and accelerates corneal epithelial healing.
Hara
R
R
Department of Ophthalmology, Sinnittetsu Hirohata Works Hospital, Japan.
Katakami
C
C
Yamamoto
M
M
D000818:Animals; D002455:Cell Division / Q000187:drug effects; D002478:Cells, Cultured; D004357:Drug Synergism; D019573:Epithelium, Corneal / Q000166:cytology* / Q000187:drug effects; D007334:Insulin-Like Growth Factor I / Q000494:pharmacology*; D011817:Rabbits; D013373:Substance P / Q000494:pharmacology*; D014945:Wound Healing / Q000187:drug effects
D013373:Substance P; D007334:Insulin-Like Growth Factor I