X-ray microanalysis and ion microscopy of guinea pig cochlea and kidney after cisplatin treatment

The detection of platinum in cochlear outer hair cells (OHCs) and renal proximal tubule cells was attempted by X-ray microanalysis and ion microscopy. Platinum was not detected by X-ray microanalysis in the lysosomes of OHCs or proximal tubule cells after 10 days treatment with 1.5 mg/kg of cisplatin. In the guinea pigs treated with 1.5 mg/kg of cisplatin for 14 days, platinum was detected by a wave-length-dispersive microanalyzer in only the lysosomes of kidney fixed by freezing. Ion microscopy failed to detect platinum. Improvement of fixation methods, longer administration of cisplatin and the use of more sensitive tools will be needed to detect the platinum inside the OHCs.