| The kidneys of the frog, Xenopus laevis, contain flask cells that purportedly play a vital role in acid-base balance. When studied using freeze fracture electron microscopy, these cells have been shown to contain rod-shaped particles in their plasma membranes that are believed to be the intramembranous portions of proton pumps. The area of the flask and flask membrane length was found to be reduced when the frogs were placed in hyperosmotic medium. Following osmotic stress, the flask area and membrane length increased when the frog received an injection of HCl. It was found using PAGE-autoradiography that frogs receiving the acid treatment incorporated more ;It is proposed that the 69 kd XLepi antigen is homologous to the 70 kd subunit of the plasma membrane proton pump reported in bovine kidney. XLepi mAb will be used to isolate and further analyze the antigen for ATPase activity and potential for electrogenic proton transport. |
