Editorial: What can insect malpighian tubules reveal about human diseases?

Abstract

It is now more than fifty years since Ramsay first pointed out the potential usefulness of the insect malpighian tubule for the study of epithelial transport. The tubules, composed of a single layer of cells, extending from the junction of the mid- and hind gut, are the principal organs of osmoregulation and excretion in insects. Ramsay devised a brilliantly simple method for studying these tubules, a technique which remains essentially that used today. Such an experimental preparation possessed all the essential features for the study of epithelial transport of salts and water, the ability to control and assay the composition of the fluids on both sides of the cells, to measure the electrical potential difference across the tissue, and to penetrate with microelectrodes the cellular cytoplasm, and thus determine the intracellular electrical potential, and ion activities. Yet in spite of some 1000 papers on the properties of malpighian tubules, some details of the mechanism by which they produce secretion remain obscure.