DISTRIBUTION OF MUCOSUBSTANCES IN THE DEVELOPING RAT HEART

摘要: Mucosubstances (MS) were examined in 10½-14½-day embryonic rat hearts utilizing nonaqueous fixatives or formaldehyde vapor-fixed frozen sections hydrated concentrated solutions of cetylpyridinium chloride. Ribonuclease-resistant, polyanionic sites limited to the extracellular cardiac jelly, endocardium and fibroblastic cells (cushion tissue) associated with endocardium. The jelly day 10½ embryos principally contained a hyaluronic acid-like carboxylated mucosubstance whose alcianophilia at pH 2.5 was abolished by hyaluronidase but resistant NaOH extraction neuraminidase trypsin digestion. A critical electrolyte concentration 0.2 M MgCl2 alcianophilia. On days 13½-14½ MS restricted cushion tissue partially resisted mild methylation. Sulfated primitive endocardial which gave origin tissue. Dye deposits aldehyde fuchsin, high iron diamine Alcian Blue (pH 1.0) localized on ...