Looking for RER granules in alveolar type II cells necessitated going back through hundreds upon hundreds of electron micrographs from about 9 different mammalian species, some experimental like this particular animal (#20) from an inhalation study with a colleague. This animal received 300 ppm ethoxyethanol for several weeks. (I would have to look up the original data to know how many weeks – I should do that).  But the purpose here was to see whether there was any appearance of plaited protein organization within the RER profiles of the cytoplasm.

This electron micrograph shows some odd cisternae of RER, but nothing that really resembles the RER granules found in guinea pig and ferret and to a lesser extent in dog.  The profiles here (highlighted in cyan) do have a few more invaginations than typically seen, at least I have to assume that this is what they are, rather than any oddly organized proteins within.  I was tempted to see them as organizaed protein initially, but think it is just the result of tangential section through more tubular rather than a more sheet-like profiles of RER.  Long evans hooded male rat, Neg 9911, animal @0, block 26538, 10,000 mag, pole piece V (Siemens 1A), enlargement 4x.