title: Fluorescent histochemical demonstration of cathepsin B in the rat yolk sac.
abstract: Fluorescence demonstration of cathepsin B (E.C. 3.4.22.1) activity was performed in the yolk sac of rats near term (18th day of gestation). The enzyme demonstration was performed on freeze-dried and celloidin mounted yolk-sac sections using different substituted beta-naphthylamide derivatives as substrates and nitrosalicylaldehyde as coupling agent. The discrete reaction products are localized preferentially in the apical part of the visceral yolk-sac epithelium. There is little doubt that cathepsin B is contained here in the well developed lysosomal apparatus of the yolk-sac epithelium.
mesh_terms: D000818:Animals; D002401:Cathepsin B; D002403:Cathepsins / Q000032:analysis*; D005260:Female; D005453:Fluorescence; D006651:Histocytochemistry / Q000379:methods; D011247:Pregnancy; D051381:Rats; D011919:Rats, Inbred Strains; D013194:Staining and Labeling / Q000379:methods; D015017:Yolk Sac / Q000201:enzymology*
chemical_list: D002403:Cathepsins; D002401:Cathepsin B