[Method of measurement of cadmium influx by fura-2 titration in MDCK cell evidenced. Fluorescence video-microscopy study].
Cadmium influx rate in mammal kidney cells (MDCK) is analyzed using an original method based on fura-2 titration. The method relies on the high affinity of the fluorophore for the metal. It follows that the excitation spectrum shift of fura-2 can be linearly correlated to the influx rate of cadmium. Fluorescence digital imaging microscopy allows the study at single cell and intra-cellular organite levels. Results show that the cadmium uptake seems to be carrier dependent. Metal fluxes are potential independent, with a temperature effect caracterized by a Q10 of 2.3 +/- 0.2. No effect of verapamil is noticed; however, cadmium transport is inhibited by external calcium. Apparent dissociation constant for the cadmium uptake is estimated at 4.5 10(-5) M at 20 degrees C. An additional passive transmembrane diffusion process is also evidenced.
Grouselle
M
M
Centre de recherche Paul-Pascal, CNRS, Pessac, France.
Boudou
A
A
Oreja-Erroz
B
B
D000818:Animals; D002104:Cadmium / Q000037:antagonists & inhibitors / Q000493:pharmacokinetics*; D002118:Calcium / Q000494:pharmacology; D002121:Calcium Channel Blockers / Q000494:pharmacology; D002460:Cell Line; D016257:Fura-2; D007668:Kidney / Q000166:cytology* / Q000378:metabolism*; D008856:Microscopy, Fluorescence / Q000379:methods; D018715:Microscopy, Video / Q000379:methods; D013696:Temperature; D014700:Verapamil / Q000494:pharmacology
D002121:Calcium Channel Blockers; D002104:Cadmium; D014700:Verapamil; D002118:Calcium; D016257:Fura-2
Méthode de mesure des flux entrants de cadmium par titration du fura-2, à l'échelle d'une cellule MDCK. Etude par vidéo-microscopie de fluorescence.