8-methoxypsoralen and long ultraviolet effects on the rat lens: experiments with high dosage.
The effect of systemic 8-methoxypsoralen (8-MOP; 100 mg/kg daily) and subsequent long ultraviolet irradiation (UVA; 300 mJ/cm2; peak: 365 nm) on albino and pigmented rat eyes was studied in a 3-dimensional experimental set-up. While 8-MOP and UVA did not cause any ocular pathology when administered alone, a combined application of the two factors caused reversible corneal opacities, and irreversible iris devascularisation and cataracts. The irreversible changes were seen only in the albinos and accompanied by a significant decrease in lens wet weight. Phosphorescence and EPR spectroscopy demonstrated the formation of an 8-MOP-protein photoadduct in the animals treated with both 8-MOP and UVA. The results of this study emphasize the necessity of shielding the eyes of patients on photochemotherapy with protective spectacles.
D000818:Animals; D002386:Cataract / Q000139:chemically induced; D003318:Corneal Opacity / Q000139:chemically induced; D004305:Dose-Response Relationship, Drug; D005128:Eye Diseases / Q000139:chemically induced*; D007908:Lens, Crystalline / Q000187:drug effects* / Q000473:pathology / Q000528:radiation effects; D008730:Methoxsalen / Q000008:administration & dosage / Q000627:therapeutic use*; D009929:Organ Size / Q000187:drug effects; D011701:PUVA Therapy / Q000009:adverse effects*; D010778:Photochemotherapy / Q000009:adverse effects*; D051381:Rats; D013057:Spectrum Analysis
D008730:Methoxsalen