In vitro subacute cataractogenic study in rainbow trout lens

Area of Science:

• Ophthalmology
• Toxicology
• Biochemistry

Background:

• Crystalline lenses of rainbow trout remain transparent and stable in H10 medium at 0°C for extended periods.
• This stability suggests potential for using trout lenses as an in vitro model for toxicological studies.

Purpose of the Study:

• To investigate the applicability of the rainbow trout lens incubation system for assessing drug toxicity.
• To identify reliable biochemical markers for drug-induced lens opacification.

Main Methods:

• Rainbow trout lenses were incubated at 0°C and exposed to various chemicals including diamide, PCMB, NEM, 1,2-naphthoquinone, ouabain, and valinomycin.
• Changes in cation levels (specifically Na+/K+ ratio), glutathione (GSH) levels, and lactic acid production were monitored.
• Macroscopic observation of lens opacification was correlated with biochemical parameter changes.

Main Results:

• An increased Na+/K+ ratio was the most sensitive indicator of lens opacification, mirroring findings in mammalian lenses.
• Valinomycin demonstrated the highest potency, inducing opacification at a low concentration of 1.0 x 10⁻¹⁰ M.
• Rainbow trout lenses detected toxicities at concentrations 1000 times lower than those required for mouse lenses.

Conclusions:

• The rainbow trout lens system is a sensitive and cost-effective model for long-term drug toxicity assessment.
• The Na+/K+ ratio serves as a robust biochemical parameter for detecting lens opacification and evaluating drug toxicity.
• This model facilitates the study of lens opacification mechanisms and long-term drug effects at reduced concentrations.