Quantification of mast cells and microflora in the vaginal cul-de-sac of the brushtail possum (Trichosurus vulpecula).
Mast cells are typically associated with biological responses to intracellular parasitic or bacterial invasion in gut and pulmonary tissues. Large numbers of these cells are present in the vaginal cul-de-sac, a component of the reproductive tract in female brushtail possums (Trichosurus vulpecula). The presence of mast cells in this area may reflect microbial presence or indicate a role for mast cells in reproductive function in this marsupial. In this study, the number and spatial location of mast cells in vaginal cul-de-sac tissues at different reproductive stages was determined, and related to the presence of microflora. Vaginal cul-de-sac tissue was collected from juvenile (n = 5), lactationally anoestrous and cyclic adult brushtail possums (n = 6 per group). Oestrous cyclicity was induced by removal of pouch young and reproductive status was confirmed by laparoscopy. Tissue was collected aseptically for microbiological procedures. The fractionator and optical disector stereological methods were used to quantify mast cell populations. In all groups, microflora populations were low (< 5 x 10(5) organisms g(-1)). Mast cell density in epithelial tissue was highest in lactationally anoestrous and luteal phase brushtail possums and lowest in follicular phase animals. No correlation between the numbers of bacteria isolated and mast cell density was apparent. Gram stained tissue showed no evidence of bacterial invasion. Mast cell density was significantly lower in epithelial tissue from follicular phase animals, corroborating previous studies in which an increase in mast cell degranulation coincided with high oestrogen concentrations.
Mahoney
P M
PM
Department of Anatomy and Structural Biology, University of Otago, PO Box 56, Dunedin, New Zealand. trish.mahoney@stonebow.otago.ac.nz
Hurst
P R
PR
McLeod
B J
BJ
McConnell
M A
MA
D000780:Anestrus; D000818:Animals; D001419:Bacteria / Q000302:isolation & purification*; D002452:Cell Count; D005260:Female; D005498:Follicular Phase; D008183:Luteal Phase; D008407:Mast Cells / Q000166:cytology*; D009893:Opossums / Q000033:anatomy & histology / Q000382:microbiology*; D014621:Vagina / Q000166:cytology / Q000382:microbiology*