Throwing New Light on Kidney Function

The Experimental Nephrology laboratory at University Hospital Münster, Germany, is using an Infinite® M200 microplate reader from Tecan to help investigate regulation of membrane transport in the kidneys. The group is particularly interested in the regulation of organic cation transport across the cell membrane, as Dr Giuliano Ciarimboli, deputy head of the Experimental Nephrology group, explained: “Organic cations cannot permeate the cell membrane, and are taken up by cells through membrane proteins known as organic cation transporters (OCTs). However, these proteins can also transport many drugs – such as the chemotherapy drug cisplatin – into the kidneys, with nephrotoxic consequences.”

According to Dr Ciarimboli, the group has been investigating transport of organic cations since 1994: “Our work was earlier based on a complex microscopy technique using the fluorescent dye ASP+, however, this method was time-consuming and expensive, and we began looking for an alternative strategy to investigate delocalised cation transport. Using the Tecan Infinite M200 reader allows us to work in 96-well microplate format, significantly increasing throughput and minimising reagent usage. The Infinite’s dual injector option allows ASP+ to be injected together with another OCT substrate, for rapid determination of IC50 values. The microplate technique shows very good correlation with our microscopy-based method, achieving near identical inhibition curves. Moreover, this

technique is also suitable to investigate acute regulation of the transporters.”

He concluded: “Tecan has been very supportive of our work here, and we always receive expert assistance when we are developing new techniques.”