Cyclo-peptide CHSDGIC on promoting healing of corneal alkali burn in rabbits

Objective To investigate the effects of cyclo-peptide CHSDGIC derived from pituitary adenylate cyclase-activating polypeptide(PACAP) on corneal alkali burns for clinical therapy.Methods Corneal alkali burn models were made using New Zealand white rabbits.Fourteen rabbits were divided into 2 groups after alkali burn at random.Rabbits in experimental group were subdued with the instillation of CHSDGIC eye drops(100 μmol·L-1),3 times a day for 21 days;Rabbits in control group were treated with saline.Ocular anterior segment were checked,and corneal tinting area were measured through corneal fluorescein staining at different time points(at the 2nd,7th,14th and 21st day after alkali burn) during the treatment.Histological examinations were performed after the treatment.Results The corneal tinting area at different time points(at the 2nd,7th,14th and 21st day) in the experimental group were(1.85±0.10)mm2,(4.56±0.22)mm2,(3.39±0.13)mm2,(0.44±0.10)mm2,and in the control group were(2.33±0.15)mm2,(6.80±0.26)mm2,(9.09±0.24)mm2,(5.03±0.24)mm2.Significant differences were found between the two groups(all P0.05).Histological examinations revealed that the corneal epithelium was well reintegrated and vascular endothelial cells and inflammatory cells were barely found in the corneal stroma compared in experimental group.Conclusion Cycol-peptide CHSDGIC can promote epithelial healing in corneal alkali burns,which may be a potent therapy for corneal integrity and transparency.