Collagenase was demonstrated in the epithelium in eight of ten corneal explants of thyroxineinduced metamorphosing tadpoles. There was no detection of collagenase in explants of "resting" control tadpoles, or in explants denuded of their epithelium in the metamorphosing series. The implications of such an enzyme in the morphological changes occurring in the cornea which accompany metamorphosis are discussed.
Slansky HH, Tolpin DW, Webster RG. Collagenolytic Activity in the Cornea of the Metamorphosing Tadpole. Arch Ophthalmol. 1970;83(6):760-764. doi:10.1001/archopht.1970.00990030760016