A study on distribution of different hydroxyproline fractions in the bovine ocular tissues

The purpose of this study was to determine the content of total, free, pept ide-bound, protein-bound, soluble- and insoluble-collagen hydroxyproline (H yp) in tissues of bovine eye. The results show that lens had the highest co ntent of free Hyp. This was followed by cornea, retina, iris and aqueous hu mor. The difference between the Hyp content of lens and iris (p < 0.01) and aqueous humor (p < 0.001) was significant. The peptide-bound Hyp was highe st in iris followed by cornea, ciliary body, sclera, lens, aqueous humor an d retina. Significant differences (p < 0.001) was observed between the conc entration of peptide-bound Hyp of iris and ciliary body, sclera, lens, aque ous humor and retina. Protein-bound Hyp was highest in iris, followed by ci liary body, sclera, cornea, lens, retina and aqueous humor. The difference between the protein-bound Hyp levels of iris and sclera, cornea, lens, reti na and aqueous humor was significant (p < 0.001). No peptide-bound and prot ein-bound Hyp was detected in vitreous humor. Iris had the highest content of total Hyp. This was followed by cornea, ciliary body, sclera, lens, reti na, vitreous humor and aqueous humor. The difference in the Hyp content of iris with ciliary body, sclera, lens, retina, vitreous humor and aqueous hu mor was significant (p < 0.001). Cornea had significantly (p < 0.001) highe r content of soluble- and insoluble-collagen Hyp as compared to other tissu es. This was followed by ciliary body, sclera, lens, iris and retina. Iris had the highest content of collagen. This was followed by cornea, ciliary b ody, sclera, lens, retina, vitreous humor and aqueous humor. The difference in the collagen content of iris with ciliary body, sclera, lens, retina, v itreous humor and aqueous humor was significant (p < 0.001).