Determination of metallothioneins by HPLC: application to zinc metabolism

Metallothioneins (MT) are well known Zn and Cu tissue proteins. Their level is mainly regulated by Zn. Therefore, they have been suggested as an index of Zn status. The determination of MT has been performed by HPLC (fitted with UV-detector) following a preparation phase (heating, ultracentrifugation and filtration). This method allows direct quantification of MT in tissues and shows a good correlation between MT concentrations and peak heights (r2 = 0.995; a = 774.73; b = -148.38) from 0 to 10 micrograms/100 microL. MT determination by RP-HPLC method allows to assess the tissue zinc status as displayed by the correlation between hepatic zinc and metallothionein concentrations (r2 = 0.82; p < 0.001). Variations of MT in response to Zn intakes are observed within 24 hours and for a physiological range of dietary Zn intakes.