title: Engagement of the periesophageal ring during Holothuria polii response to erythrocyte injection.
abstract: In Holothuria polii, the periesophageal ring is an important organ supplying spherule cells after stimulation with foreign material. In animals injected with formalinized sheep erythrocytes, in fact, a depletion of spherule cells is observed in the periesophageal ring, whereas in the connective tissue, in the external epithelium and around the antigen-injected site, small, transparent cells can be visualized. It is supposed that the latter are stem cells of spherule cells.
authors.affiliation: Istituto di Istologia ed Embrologia, Facoltà di Scienze, MM.FF.NN, Università di Palermo, Italy. dancona@unipa.it
authors.forename: G
authors.initials: G
authors.lastname: D'Ancona Lunetta
authors.forename: M L
authors.initials: ML
authors.lastname: Michelucci
mesh_terms: D000818:Animals; D000941:Antigens / Q000008:administration & dosage; D002452:Cell Count; D002455:Cell Division; D004912:Erythrocytes / Q000187:drug effects / Q000276:immunology*; D004947:Esophagus / Q000276:immunology / Q000473:pathology*; D005557:Formaldehyde / Q000494:pharmacology; D007249:Inflammation / Q000276:immunology / Q000473:pathology*; D012616:Sea Cucumbers / Q000276:immunology*
chemical_list: D000941:Antigens; D005557:Formaldehyde