title: Human corneal endothelial tolerance to glycerol, dimethylsulfoxide, 1,2-propanediol, and 2,3-butanediol.
abstract: We exposed human corneas to various concentrations of four cryoprotectants by one of two methods: a gradual increase to the final concentration (ramp method) and a series of steps to the final concentration (step method). Endothelial damage was manifest as a decrease in the number of endothelial cells per unit area. The highest concentrations that did not cause a loss of endothelial cells by the ramp and step methods, respectively, were 4.3 and 2.0 M glycerol, 2.0 and 4.3 M dimethylsulfoxide, 2.0 and 3.0 M 1,2-propanediol, and 2.0 and 2.5 M 2,3-butanediol. The ramp method achieved higher final concentrations with the more slowly permeating glycerol, but required low toxicity. The step method achieved higher final concentrations with the more toxic cryoprotectants by limiting the exposure time, but required more rapid permeation. None of the four cryoprotectants was tolerated at concentrations sufficient for vitrification at practical cooling and warming rates.
authors.affiliation: Department of Ophthalmology, Mayo Clinic, Rochester, Minnesota 55905.
authors.forename: W M
authors.initials: WM
authors.lastname: Bourne
authors.forename: D R
authors.initials: DR
authors.lastname: Shearer
authors.forename: L R
authors.initials: LR
authors.lastname: Nelson
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002072:Butylene Glycols / Q000008:administration & dosage / Q000009:adverse effects; D015925:Cryopreservation / Q000379:methods; D003451:Cryoprotective Agents / Q000008:administration & dosage / Q000009:adverse effects*; D004121:Dimethyl Sulfoxide / Q000008:administration & dosage / Q000009:adverse effects; D004361:Drug Tolerance; D004728:Endothelium, Corneal / Q000187:drug effects* / Q000293:injuries; D005069:Evaluation Studies as Topic; D005990:Glycerol / Q000008:administration & dosage / Q000009:adverse effects; D006801:Humans; D066298:In Vitro Techniques; D008875:Middle Aged; D019946:Propylene Glycol; D011409:Propylene Glycols / Q000008:administration & dosage / Q000009:adverse effects
chemical_list: D002072:Butylene Glycols; D003451:Cryoprotective Agents; D011409:Propylene Glycols; C026978:2,3-butylene glycol; D019946:Propylene Glycol; D005990:Glycerol; D004121:Dimethyl Sulfoxide