tubule fluid samples from proximal tubules of superficial , reptilian-type nephrons of the european starling ( sturnus vulgaris ) were obtained by micropuncture and , along with plasma samples , were analyzed for urate by high performance liquid chromatography with electrochemical detection , as well as for the elements sodium , chloride , calcium , magnesium , phosphorus and potassium by electron microprobe analysis .
C0013879
elements
C0031705
phosphorus