A comparative study of local defense spots within the peritoneal cavity in Japanese quails,Coturnix coturnix japonica(Galliformes, Phasianidae) and Wistar rats,Rattus norvegicus(Rodentia, Muridae)

Abstract

The local defense spots (milky spot) are found on the greater omentum but also in other peritoneal regions, as well as on the pleura and pericardium. Milky spots are small accumulations of leukocytes scattered around the capillaries. The most frequent cells in milky spots are the macrophages, followed by lymphocytes and mast cells. In this study, the structure of milky spots of quails and rats after antigenic stimulation with bovine serum albumin were examined at the light microscope levels by applying conventional histochemical and immunohistochemical methods. The parietal peritoneum and mesentery samples from quails and parietal peritoneum, mesentery and omentum majus samples from rats were collected. Local defense spots were seen as local lymphoid cell aggregations in the omentum, mesentery and parietal peritoneum in rats, whereas in quails they were seen only in the mesentery. After the bovine serum albumin injection, the dimensions of spots were at their biggest 6 hours after injection (p < 0.001) in the rat and 1 hour after injection (p < 0.01) in the quail. Lymphocytes, macrophages (MHC II positive cells in quail), plasma cells and mast cells were detected within the aggregates of both rat and quails. In conclusion, it was determined that the quails have local defense spots at the mesentery like the milky spots of rats. In addition, the present study findings confirm that local defense spots react to antigenic stimulation by innate and adaptive immunity in rats and quails.