X-ray microanalysis of bulk hydrated specimens of neoplastic and non-neoplastic human urothelium

Specimens of neoplastic and non-neoplastic human urothelium were rapidly frozen against a copper block immersed in liquid nitrogen, planed in a cryoultramicrotome and then examined by low-temperature scanning electron microscopy (LTSEM) following coating by aluminium. Energy dispersive X-ray microanalysis (XRMA) was performed on the superficial urothelial cells and on gelatin blocks mounted in parallel which had known concentrations of sodium, potassium, chloride, and phosphorus. The neoplastic urothelial cells had significantly less phosphorus (P less than 0.05) than non-neoplastic cells and the ratios K+/P,K+/Na+, and K+/Cl- were significantly higher in neoplastic cells than in non-neoplastic cells (P less than 0.00001). These results are consistent with those expected in cells with a sustained increase in intracellular pH caused by stimulation of Na+/H+ ion membrane exchange.