IMMUNOCYTOCHEMICAL LOCALIZATION OF A VACUOLAR-TYPE ATPASE IN MALPIGHIAN TUBULES OF THE ANT FORMICA-POLYCTENA

The presence of a vacuolar-type ATPase in Malpighian tubules of the an t Formica polyctena was investigated immunocytochemically, using antib odies to vacuolar ATPases of Manduca sexta midgut and bovine kidney. S pecific labelling was observed at the brush border of the epithelium, extending along the entire length of the tubules. These findings agree with the current view that a vacuolar ATPase is situated at the apica l membrane of Malpighian tubule cells and other insect epithelial cell s, being the energizing element of an electrogenic potassium pump. Whe n antibodies were tested on tubules in different secretion conditions prior to fixation, no differences were observed in the distribution of the vacuolar ATPase.