Histochemical and quantitative biochemical changes in mucopolysaccharides of the term placenta of the diabetic rat.
Full-term placentae of rats with streptozotocin-induced diabetes were analysed histochemically and biochemically for changes in mucopolysaccharide content. The experimental diabetes induced severe cystic degeneration in the spongiosa zone of the placenta and this was accompanied by extracellular deposition of hyaluronate and neutral polysaccharides. The labyrinth zone was affected to a lesser extent. Biochemical analysis also revealed quantitative differences in the total contents of mucopolysaccharides (MPS) between the two zones of the placenta in both diabetic and normal placentae. The spongiosa had a higher total mucopolysaccharide content than the labyrinth. Polysaccharides of low molecular weight were always predominant. The amount of hyaluronate exceeded the quantitites of sulphated mucopolysaccharides which were found in relatively small amounts in both placental zones. In diabetic placentae there was a two- to threefold increase, which was more pronounced in the spongiosa. The increase was observed among all types of MPS. A close correlation between the accumulation of MPS in the placenta and the degree of maternal hyperglycaemia was found. The placentae of the three streptozotocin-resistant animals showed neither histological nor biochemical changes. It is suggested that the accumulation of MPS in the diabetic placenta might be a consequence of a shift in carbohydrate metabolism induced by hyperglycaemia or a persistence of the fetal metabolic features as a part of a retarded maturational process of the placenta.
D000818:Animals; D003921:Diabetes Mellitus, Experimental / Q000378:metabolism*; D005260:Female; D006025:Glycosaminoglycans / Q000032:analysis*; D006651:Histocytochemistry; D010920:Placenta / Q000032:analysis* / Q000473:pathology; D011247:Pregnancy; D011254:Pregnancy in Diabetics / Q000378:metabolism*; D051381:Rats; D011919:Rats, Inbred Strains
D006025:Glycosaminoglycans