Research On Morphology And Histochemistry Of Mast Cells In Bovine Mammary Gands

This research was conducted to study the morphology and histochemical properties of mast cells in bovine mammary glands during each period by method of special staining, transmission electron microscopy and immunohistochemistry. This would provide guidance for further study on the mechanism of immunopathology of cow mastitis, its diagnosis and treatment.Specimen of mammary gland from 21 healthy dairy cow of different stages were selected. These stages were non-pregnant stage and the other 6 stages after parturition including 8,20,60,120,240 and 300 days These specimen were fixed by Carnoy's fluid and neutral formalin. The result of five parts of test was as followed.1. HE staining was used to observe the morphological change in different period of breast.The results showed that there was large amount of connective tissue and small alveolus in non-pregnant mammary gland. After parturition, the number of alveolus increased, the acinar cavity was full of milk. The number of alveolus was the most in mammary of 60 days after parturition, and the amount of connective tissue was the lest among all stages. The number of alveolus decreased in mammary of 120 days after parturition, the acinar cavity became smaller and the connective tissue increased.2. The modified toluidine blue staining (MTB) method and Alcian blue-Safranin O staining (AB/S)method were employed to investigate the distribution and number of mast cells. The results showed that the mast cells had various shapes during each period. Most of them were located in the interalveolar stroma and intralobular connective tissue. Compared with non-lactating period, the number of mast cells decreased remarkably during lactating period (P＜0.01).The number of mast cells was the lest in mammary gland 60 days after parturition. Meanwhile the effect of two staining methods was compared. The results showed that the mast cells were only stained blue by Alcian blue. Mast cells can be shown well by being fixed by Carnoy'liquid and dyed by MTB.The results showed that mucosal mast cells existed in mammary glands.3. The effect was compared of two staining methods including MTB and AB-S and two fixing liquid including Carnoy's fluid and neutral formalin. The results showed that the mast cells were only stained blue by Alcian blue, the effect of Carnoy was better than that of neutral formalin, the effect of MTB was the better.4. Mast cells in different developmental stages of breast were observed by electron microscopy. The results showed that there was no significant difference in ultrastructure among different periods of mammary gland.5. Immunohistochemical method was employed to investigate the expression of tryptase and 5-HT of mast cells of mammary gland. The results showed that the rule of the distribution of mast cells was similar to that of the toluidine blue positive cells.