Mononuclear and IgA-containing cells in the lacrimal gland of germ-free and conventional rats.
Mononuclear cells in the lacrimal (exorbital) glands of five germ-free, five ex-germ-free, and five age-matched conventional rats were counted by light microscopy. Tissues from these rats were also examined by electron microscopy. IgA-containing plasma cells were counted by immunofluorescence microscopy in the lacrimal glands of five germ-free and five conventional rats. The median number (and range) of mononuclear cells per ten high-power fields was 25 (14-28) in germ-free rats, 33 (32-43) in ex-germ-free rats, and 41 (36-50) in conventional rats. The median number (and range) of IgA-containing plasma cells per ten high-power fields was two (0-5) in germ-free and 44 (29-72) in conventional rats. The differences in the numbers of mononuclear cells in the lacrimal glands of germ-free as compared with ex-germ-free and with conventional rats were statistically significant (P less than 0.004). The difference between the numbers of IgA-containing plasma cells in germ-free as compared with conventional rats was also statistically significant (P less than 0.004). Electron microscopy revealed that the mononuclear cells in all groups of rats consisted of macrophages and lymphocytes. These observations suggest that the number of mononuclear cells, and particularly IgA-containing plasma cells, in the rat lacrimal gland can be increased by systemic and/or local immunologic stimulation.
D000818:Animals; D002452:Cell Count; D005856:Germ-Free Life; D007070:Immunoglobulin A; D007765:Lacrimal Apparatus / Q000276:immunology / Q000648:ultrastructure*; D008214:Lymphocytes / Q000648:ultrastructure*; D008264:Macrophages / Q000648:ultrastructure*; D008297:Male; D008854:Microscopy, Electron; D008856:Microscopy, Fluorescence; D010950:Plasma Cells / Q000276:immunology; D051381:Rats; D011919:Rats, Inbred Strains
D007070:Immunoglobulin A