Histochemical heterogeneity of dermal mast cells in athymic and normal rats

Abstract

Mucosal mast cells (MMC) and connective tissue mast cells (CTMC) of the rat contain different proteoglycans, which can be distinguished using histochemical methods. The chondroitin sulphate proteoglycan of the MMC, unlike the heparin of the CTMC, does not show fluorescent berberine binding, is susceptible to aldehyde fixatives and stains preferentially with Alcian Blue in a staining sequence with Safranin. The majority of the dermal mast cells are typical CTMC and are located in the deep part of the dermis. Subepidermal mast cells are comparatively few in normal rats but numerous in athymic rats and mice. These cells differ from other dermal mast cells in that they stain preferentially with Alcian Blue and they appear to contain little histamine. We examined some of the histochemical properties of the skin mast cells of female PVG-rnu/rnu rats and their heterozygous littermates aged from 5 to 29 weeks. The thiazine dye-binding of the subepidermal mast cells was partially blocked by formaldehyde fixation and only about half of them showed a weakly fluorescent berberine binding. The critical electrolyte concentration of the Alcian Blue staining of the subepidermal mast cells was between that of CTMC and MMC. Deaminative cleavage with nitrous acid abolished the staining of all skin mast cells, while that of the MMC was unaffected. There were no statistically significant differences in the staining patterns of the dermal mast cells between different ages or groups of rat. These results indicate that the subepidermal mast cells contain a heparin proteoglycan which is, however, different from that of the typical CTMC of other sites. They thus appear to represent a second example of a mast cell within a defined anatomical location exhibiting a distinct proteoglycan expression.

Two Pharmacological Phases in Antigen-Induced Immediate Airway Response in Rats

“…16,17) In rodents, there are two types of mast cells, connective tissue type mast cells (CTMCs) and mucosal mast cells (MMCs). 18) These two types of cells differ not only in tissue distribution but also in pattern of mediator production. In rat airway, CTMCs and MMCs are observed in the submucosal region and epithelial layer, respectively.…”

Thymus Dependence of Compound 48/80-Induced Mucosal Mast Cell Proliferation

“…In situ histochemical analysis of the proteoglycans of the subepidermal CTMC has thus shown that they con tain a heparin proteoglycan which is different from that of the MMC [Aldenborg and Enerback, 1986],…”

“…These cells, like the MMC, appear to contain little histamine, stain with alcian blue in a staining sequence with safranin, and show a cationic dye-binding which is susceptible to blocking by formaldehyde [Aldenborg and Enerback, 1986].…”

Lectin histochemistry of the mast cell: Heterogeneity of rodent and human mast cell populations

“…0018-2214/90 $03.00 +.12 9 1990 Chapman and Hall Ltd. their staining to nitrous acid and variation of ionic strength (Enerback, 1987). However, these techniques also reveal a finer degree of heterogeneity in heparincontaining mast cells in both rodents and man (Marshall et al, 1987;Aldenborg & Enerback, 1988).…”