Glycogen Infiltration

GLYCOGEN INFLTRATION, a pathological phenomenon consisting either of excessive deposition of glycogen or of its appearance in tissues and cellular regions which in the norm contain it at all (e.g. in the central nervous system, in cellular nuclei, etc.). G. i. is established in many diseases. First of all it refers to diabetes mellitus, in which, independently of its type (nervous, pancreatic, etc.), significant glycogen deposits are found in a whole series of organs. The kidneys take first place, where glycogen is deposited with great constancy, mainly in the epithelium of Henle's loops and in the part of the convoluted tubules immediately preceding them, and sometimes the amount of it here can be so great that on a freshly cut organ a reaction with iodine is macroscopically achieved. On ordinary microscopic preparations, where glycogen is extracted, the corresponding cells appear swollen and as if empty or sharply vacuolized. The reaction to glycogen is also given by some cells of the epithelium of the straight tubules, Bowman's capsule, and individual epithelial nuclei less often. Since in the normal kidney glycogen is barely definable, and its selective accumulation in the epithelium of Henle's loops occurs besides diabetes mellitus only in rare cases of certain intoxications (e.g. morphine), the described changes of the kidneys are rightly considered the most important and reliable morphological sign of diabetes. In the liver as an organ capable of physiologically containing significant deposits of glycogen, the presence of it not only in the protoplasm but also in the nuclei of liver cells is characteristic for diabetes mellitus (with the exception of cases of death from coma). The nuclei swell, lose their chromatinic pattern and acquire a bubble-like appearance, becoming quite similar to nuclei in vacuolar degeneration (see), with the only difference that instead of watery fluid various-sized droplets of glycogen are found in them. From other organs, which give no reactions to glycogen in the norm but contain it in diabetes, one should name the central nervous system (where it is deposited mainly in glial elements, rarely in ganglion cells), then the optic nerve and the retina of the eye. Besides diabetes G. i. is observed in the following pathological conditions. 1. In disorders of circulation, e.g. in the liver and in the kidneys in venous stasis, as well as in anemic areas (obtained e.g. on the basis of stenosis of the supplying vessel). At the edge of anemic infarcts (kidneys, myocardium) containing glycogen are not only epithelium and muscle fibers but also connective tissue cells, endothelium and leukocytes. 2. In infectious and toxic influences on tissues, glycogen often appears in blood leukocytes, predominantly neutrophilic (in anemic states, leukemias and many infectious diseases), as well as in many cellular elements (stable cells of connective tissue, granulation elements, endothelium, leukocytes, etc.) located in the area of various inflammatory processes of both exudative and proliferative character (abscesses, tuberculous and syphilitic granulomas, etc.). 3. In some tumors, mainly those which are distinguished by immaturity or embryonal type of the cells constituting them or which originate from tissues normally containing significant amounts of glycogen (e.g. chondroma). According to data of Lubarsch (Lu-barsch), based on the study of more than 1.500 tumors, teratomas, rhabdomyomas, hypernephroid tumors and chorionepitheliomas contain glycogen in 100%, sarcomas in 57%, carcinomas in 44%; fibromas, osteomas, angiomas and gliomas never detect it. The significance of G. i. in relation to each individual case can far from always be established, since the appearance or increase of glycogen in the tissue is dependent on a whole series of factors (on the structure and properties of the cellular elements themselves, on the phase of their carbohydrate metabolism, on the character and strength of the damaging agent, etc.). The same histological picture of glycogen deposits can result either from excessive supply or resorptive assimilation of the corresponding nutrient material, or thanks to a decrease in the cell's capacity for further processing of the nutrient material, or perhaps even as a result of molecular disintegration of the cell. Thus the evaluation and interpretation of the morphological data obtained by us in this field requires great caution for now.