Cervical lymph nodes and mast cells in the marsupial Sminthopsis crassicaudata

Abstract

A study of the cervical lymph nodes from the fat-tailed dunnart, Sminthopsis crassicaudata, revealed the nodes were pigmented with lipofuscin and contained many large cells which were identified as mast cells from their ultrastructure and histochemical staining properties. It is believed that the very high density of mast cells in the cervical lymph nodes contributed to a n increase in size of these organs compared to other animals. Very high levels of histamine (90 pg/g) were found in the nodes. Cervical lymph nodes with these unusual features were found not only in healthy, unprimed laboratory bred adults, but also in pouch young, wild caught animals, and adults of the closely related species, Sminthopsis macroura.

Ultrastructural Changes in the Cervical Epithelium during the Estrous Cycle of the Marsupial <i>Monodelphis domestica</i> (Grey Short-Tailed Opossum)

“…The ultrastructural pictures of mast cell granules showed different electron density but no crystalline or scroll-like pattern as found in human mast cells [Drudy et al, 1991]. The same holds true for the other mast cell descriptions of marsupials, as reported by Haynes [1991], Santos and Machado [1994], and Chiarini-Garcia and Pereira [1999].…”

“…Mast cells, which are regarded as immunoregulatory cells [Metcalfe et al, 1997], have recently been described in marsupials, especially in Didelphis but only for lymph nodes, intestine and skin and not for the genital tract [Haynes, 1991;Santos and Machado, 1994;Chiarini-Garcia and Pereira, 1999;Chiarini-Garcia et al, 2000]. Mast cells staining metachromatically with toluidine blue have been mentioned in the uterus of the marsupial Bettongia by Tyndale-Biscoe [1968].…”

Ultrastructural Changes in the Uterine Luminal and Glandular Epithelium during the Oestrous Cycle of the Marsupial <i>Monodelphis domestica</i> (Grey Short-Tailed Opossum)

“…Mast cells have recently been described in marsupials, especially in Didelphis, but only in lymph nodes, intestine and skin, not in the genital tract [Haynes, 1991;Santos and Machado, 1994;Chiarini-Garcia and Pereira, 1999;Chiarini-Garcia et al, 2000]. Mast cells staining metachromatically with toluidine blue were noted in the uterus of the marsupial Bettongia by Tyndale-Biscoe [1968].…”

A Histological and Immunohistochemical Analysis of Lymphoid Tissues of the Tasmanian Devil

“…Abundance of mast cells in the lymph nodes has been described in a Dasyurid, the fattailed dunnart (Smithopsis crassicaudata), and in five Didelphidae marsupials. These mast cells were restricted to the lymphatic sinuses, contained large cytoplasmic granules and were thought to be of a different type from the connective tissue and mucosal mast cell populations (Haynes, 1991;Chiarini-Garcia and Pereira, 1999;Chiarini-Garcia et al, 2000). The medullary sinuses of the devils lymph nodes enclosed large numbers of toluidine blue positive cells, morphologically consistent with mast cells.…”