Changes in lactate dehydrogenase activity in bovine corneal stroma and epithelium in response to in vitro toxic challenges in the enucleated eye test.
OBJECTIVE
To assess whether changes in lactate dehydrogenase (LDH) activity, as a marker of cell damage, could be detected in corneal stroma and corneal epithelium after toxicity measurements using the enucleated eye test (EET).


METHODS
The corneal surface of isolated bovine eyes was continuously wetted with commercial balanced salt solution (BSS) over 4 h at 37 degrees C and central corneal thickness (CCT) was measured. Initial 5-min challenges were made with dilute solutions of benzalkonium chloride (up to 0.032%) or NaOH (up to 0.4 M). The residual LDH activity in the corneal epithelium and corneal stroma were then assessed.


RESULTS
Dose-dependent increases in CCT of up to 70% were measured. A strong correlation (r = -0.961) was found between increases in CCT and decreases in stromal LDH activity, but the correlation was much less (r = -0.512) for epithelial LDH activity.


CONCLUSIONS
LDH activity can be used as one marker for cell integrity in the corneal stroma and epithelium, although dose-dependent correlations may not be high.
Doughty
M J
MJ
Glasgow-Caledonian University, Department of Vision Sciences, Scotland.
D000818:Animals; D001548:Benzalkonium Compounds / Q000633:toxicity; D015415:Biomarkers; D002057:Burns, Chemical / Q000201:enzymology / Q000473:pathology; D002417:Cattle; D002424:Caustics / Q000633:toxicity; D003319:Corneal Stroma / Q000187:drug effects / Q000201:enzymology* / Q000648:ultrastructure; D003886:Descemet Membrane / Q000187:drug effects / Q000201:enzymology / Q000648:ultrastructure; D003902:Detergents / Q000633:toxicity; D004195:Disease Models, Animal; D004305:Dose-Response Relationship, Drug; D004848:Epithelium / Q000187:drug effects / Q000201:enzymology / Q000648:ultrastructure; D005126:Eye Burns / Q000201:enzymology / Q000473:pathology; D015353:Eye Enucleation; D066298:In Vitro Techniques; D007770:L-Lactate Dehydrogenase / Q000378:metabolism*; D008854:Microscopy, Electron; D012972:Sodium Hydroxide / Q000633:toxicity; D013053:Spectrophotometry
D001548:Benzalkonium Compounds; D015415:Biomarkers; D002424:Caustics; D003902:Detergents; D012972:Sodium Hydroxide; D007770:L-Lactate Dehydrogenase