title: Peculiar tonsil-like structure near vagina of the laboratory shrew, Suncus murinus.
abstract: After finding tonsil-like structures near the entrance of vagina of a laboratory shrew (Suncus murinus), which we subsequently designated as vaginal tonsils, we performed detailed immunohistochemical and developmental studies. The location of T and B cells in the vaginal tonsils differed from that in the palatine tonsils or that in the lymphoid nodes of other animals. The boundary between the germinal center region and the region encompassing follicular interfollicular tissue was not clear. B cells were widely distributed and very dense in the parenchyma, but they were scattered in the epithelial area (B cells were present in around 90% of the vaginal tonsil tissue). In contrast, T cells were scattered in the parenchyma and in the epithelial area (T cells were present in around 10% of the vaginal tonsil tissue). B cells were more prominent than T cells throughout the development of these structures and the epithelium was invaded by many immigrating cells. The size of the vaginal tonsils changed during postnatal development. Vaginal tonsils are structurally similar to other tonsils, and they may function to protect the vagina from infection.
authors.affiliation: Department of Anatomy, School of Health Sciences, Aichi, Japan. ksakai@fujita-hu.ac.jp
authors.forename: Kazuyoshi
authors.initials: K
authors.lastname: Sakai
authors.forename: Hideki
authors.initials: H
authors.lastname: Imada
authors.forename: Masanori
authors.initials: M
authors.lastname: Shinzato
authors.forename: Kazuhiro
authors.initials: K
authors.lastname: Nishii
authors.forename: Ei-ichi
authors.initials: E
authors.lastname: Miyachi
authors.forename: Yoshimitsu
authors.initials: Y
authors.lastname: Katoh
authors.forename: Kouji
authors.initials: K
authors.lastname: Yamada
mesh_terms: D000818:Animals; D001402:B-Lymphocytes / Q000166:cytology; D005260:Female; D018858:Germinal Center / Q000166:cytology; D008221:Lymphoid Tissue / Q000033:anatomy & histology* / Q000166:cytology; D012788:Shrews / Q000033:anatomy & histology*; D013601:T-Lymphocytes / Q000166:cytology; D014621:Vagina / Q000033:anatomy & histology*