The Altmann's granules in kidney and liver and their relation to granular and fatty degeneration

In the kidneys of dogs, rabbits and guinea pigs we find the following arrangement of the Altmann's granules: In the connecting, the convoluted tubules and in the descending parts of the loops of Henle, the granules are rather coarse, very definitely rodshaped and arranged in radial rows in the basilar two thirds of the cells, often so closely set end to end that it is difficult to make out the dividing lines between them. In the part of the cells directly adjoining the lumen there are few scattered short rodshaped granules and none in the “Bürstenbesatz.” These details are naturally more plainly shown in the large cells of the convoluted tubules but in a general way the smaller cells in the connecting tubules and in the descending loops of Henle resemble them very closely. Some groups of convoluted tubules have much coarser granules than others. I have not been able to make out whether this is a constant anatomic difference or due to different functional stages. If the granules have any relation to the function of the cells, which seems probable, one would surmise that the connecting tubules cannot purely serve the function of conducting the urine from one place to another, all the more so as in the large ducts in the pyramids which serve this purpose alone, the granules are very scanty and irregularly arranged. In the large light cells of the ascending parts of the Henle's loops the granules are exceedingly small, also slightly rodshaped, extremely numerous and scattered all through the cells in an irregular fashion. This might be used as an argument in favor of a difference in function of this portion of the tubules. In the cells of the liver of these animals the granules vary greatly in size from just visible to quite coarse granules.