Some observations on the uterus of the rat during the puerperium

This thesis deals with some of the changes that occur in the rat's uterus during the post-partum period. In the first part the behaviour of the endometrium is described with particular attention being paid to that of the epithelium. The area of endometrium left devoid of epithelium by the separation of the placenta was re-epithelialised by cells which spread inwards from the existing marginal epithelium. There was no evidence of the bare area being covered by a new epithelium arising from stromal cells. Re-epithelialisation was rapid and was completed within thirty-six hours. Glycogen was absent from both the normal and the spreading epithelium. Ribonucleic acid was present in the cytoplasm of the normal epithelial cells but was much reduced in the spreading epithelial cells. There was a vacuolar degeneration of the epithelium, similar to that which occurs during oestrus, and which was most marked at thirty-six hours. There was no evidence of exfoliation of the placental site and the endometrial portion of the placental artery appeared to be absorbed in situ. In the second part the involution of the metrial gland ifs considered. The metrial glands of lactating and non-lactating animals involute in the same way and at the same speed. Involution of the gland la rapid in the early stages, is nearly complete by fifteen days, and is finished by the twentieth day of the puerperium. Typical granulated metrial gland cell forms only a small proportion of the total cell population of the gland. They disappear by the fifth day, presumably disintegrating. They do not become lipoid containing or phagocytose pigment. The specific granules of the metrial gland cells are probably formed by a mucopolysaccharidejoined to mi alkaline protein. "Encapsulated" giant cells derived from the placental artery were present in the glands and the adjacent endometrium. These cells were multinucleate, basophilic and surrounded by a "capsule" of neutral mucopolysaccharide. They persist until the fourteenth day. The gland placental artery within the metrial was absorbed by the fifteenth day, die third section is devoted to a consideration of the characteristics of a pigment which is to be found in the metrial glands and the adjoining part of the endometrium from the second day of the puerperium onwards, the pigment was yellowish-brown in colour and was Intracellular, It contained ferric iron and can therefore be regarded as a haemosiderin. However, it had other properties, which suggest that there is also a lipid component present. This lipid component behaved in many ways like the lipogenic pigments, Lipid is not usually associated with haemosiderin