The effect of vinblastine‐induced microtubule loss on kidney podocyte morphology

The effect of intravenous injections of vinblastine sulfate on the renal glomerular epithelium was studied by scanning and transmission electron microscopy. Two hours after treatment with vinblastine, microtubules were almost completely lost from the podocyte cell bodies and major processes, and crystalline inclusions of a tubular nature had appeared within the cytoplasm. Coincident with this loss of microtubules, podocyte major processes at first collapsed and then became significantly thinner as they appeared to lose much of their cytoplasm to the nucleated cell body. These observations suggest that microtubules serve to maintain the shape and integrity of podocyte major processes. At no time after vinblastine treatment did we note any alteration in podocyte pedicel morphology.