Comparative histochemical distribution of glycogen and alkaline phosphatases in the placenta

Summary The distribution of glycogen, non-specific alkaline phosphatase, and specific phosphatases acting on adenosine monophosphate, adenosine triphosphate, inosine triphosphate, thiamine pyrophosphate, uridine diphosphate, fructose-6-phosphate, fructose-1:6-diphosphate, and glucose-6-phosphate is described in the placentae and accessory structures of the horse, sheep, cat, dog, ferret, rat, rabbit, guinea pig, and man, and in the yolk-sac of the chick, the oviviparous fish Limia maculata, and man.Correlation between the distribution of these substances and placental function is sought, and the results are discussed with respect to the trophoblast, decidua, giant cells, yolk-sac, non-placental chorion and maternal epithelium and uterine secretion, and allantois. The significance of the presence of the enzymes in the carnivore interstitial matrix, the ferret thickened endoderm and the rodent spongy zone is also considered.