Enzymatic Activity of the Isolated Glomerulus in Normal and Nephrotic Rats*

Recent studies of the nephrotic kidney have implicated the glomerulus as the primary anatomic site of injury. Using the electron microscope, Farquhar, Vernier and Good (1) and other in- vestigators have demonstrated that the most con- sistent and striking alteration is a lesion in the foot process of the glomerular epithelial cell. Hjelt, Stjernvall and Hallman (2), in a study of con- genital nephrosis, found imperfectly formed or absent foot processes. Vernier, Papenmaster and Good (3), and Harkin and Recant (4) have de- scribed similar lesions of the foot process in experi- mental nephrosis induced by the aminonucleoside of Puromycin, and Piel (5) has made similar observations in nephrosis produced by antikidney serum. In the experimentally induced lesion, glomerular injury is found prior to tubular changes (4).