Changes in numbers and heparin content of peritoneal fluid mast cells of growing rats measured by flow cytofluorometry

A cytofluorometric method, based on berberine staining of mast cell heparin, was used for flow cytofluorometric counting and heparin quantitation of mast cells in crude peritoneal suspensions of growing rats. The automatic flow cytofluorometric counting of mast cells correlated well with hemocytometer cell counts. The mean mast cell heparin content obtained by flow cytofluorometry showed good agreement with such obtained by cytofluorometry of microscopically identified mast cells. The number of peritoneal mast cells and the mean mast cell heparin content was found to increase as the animals grew older. The results of the microscope fluorometric measurements suggested that the heparin content was normally distributed within mast cell populations of both young and old rats. However, the heparin distributions obtained by flow cytofluorometry were often positively skewed but did not fulfill the condition of the log-normal distribution.     

Maturation of adult rat peritoneal and mesenteric mast cells

Summary Repopulation and maturation of rat mesenteric and peritoneal mast cells were studied after mast cell depletion by intraperitoneal injection of distilled water. Immature mast cells were first identified in the mesentery and peritoneal fluid 5 and 6 days, respectively, after water injection. The most immature mast cells that could be identified contained a few orthochromatic granules. Upon maturation, the granules became metachromatic and increased in size and number. Heparin, revealed by toluidine blue staining and berberine sulfate fluorescence, appeared simultaneously with orthophthaldialdehyde (OPT)-induced histamine fluorescence. Paraformaldehyde-induced serotonin fluorescence appeared somewhat later. Repopulation of mesentery and peritoneal fluid by mast cells seemed to be independent of each other and to occur from undifferentiated precursor cells.     

Distribution, density and heterogeneity of canine mast cells and influence of fixation techniques

 The present study was carried out to determine the physiological distribution of mast cell numbers and types in the dog according to tissue location, staining and fixation methods. Tissue samples from stomach, duodenum, lung, lymph node, skin and uterus were evaluated. Samples were fixed in formalin as well as in Carnoy’s fluid. The average number of mast cells was determined using a metachromatic staining method. Protease content of mast cells was examined with a double enzyme-immunohistochemical staining technique, using a histochemical reaction for chloroacetate esterase to detect chymase activity and an immunohistochemical staining method for the detection of tryptase. Canine mast cells can be subdivided into formalin-sensitive and -resistant mast cells. Three subtypes were identified according to their content of the mast cell-specific proteases tryptase (T) and chymase (C): T-, TC- and C-mast cells. Significant differences regarding the distribution of mast cell subtypes as well as the influence of the fixation method can be observed. This underlines the fact that data regarding mast cell heterogeneity from other species, obtained by different fixation methods, are not comparable. This fact has to be taken into consideration when evaluating mast cell subtypes under pathological conditions. Accepted: 29 January 1998     

Mast cell dynamics in the house rat (Rattus rattus) ovary during estrus cycle, pregnancy and lactation.

The distribution of mast cells in various ovarian compartments was studied during different stages of the reproductive cycles in Rattus rattus. Two types of mast cell populations were recognized with light microscopy i.e., light purple and deep purple, the latter also includes deeply stained cells with extruded granules. Mast cells identified by electron microscopy showed the ultrastructural features during granule formation and release of their content. Significantly higher numbers of mast cells per unit area of ovary were seen at estrus and diestrus. Numbers of mast cells also remained high during pregnancy with possible involvement of mast cell products in vascularization of corpora lutea. A positive correlation existed between mast cell counts and embryo number during pregnancy. However, numbers of mast cells declined significantly after parturition.     

Monitoring ofgfp-taggedMoraxella sp. under starvation condition

A PNP(p-nitrophenol)-degradingMoraxella sp. was genetically marked bygfp gene for monitoring. Stable chromosomal integration of the introducedgfp gene was confirmed by examining the transformants under epifluorescent microscope. The survival ofgfp-taggedMoraxella sp. cells during long-term storage under starvation condition was examined by viable cell counting and direct fluorescence microscopic counting. The number of green fluorescent cells obtained by direct microscopic counting was approximately 10 times greater than viable cell counts by plating. The number of cells from both counting methods was higher at lower temperature (4°C), although the drop of cell number after 8 weeks of starvation was comparable (approximately 100 fold drop from initial counts). Results obtained by two different methods correlated well with each other indicating that thegfp markedMoraxella sp. can be directly monitored following environmental release using epifluorescence microscopy.     

Selection of a simple protease procedure for identifying mast cells in routinely processed human tissues

Proteases present in mast cell granules have been harnessed to demonstrate mast cells in human tissues. A number of substrate mixtures were tested. D-Val-Leu-Arg-4-methoxy-2-naphthylamide (MNA) plus Fast Blue B was the best for identifying human mast cells, yielding the most specific and complete staining. The procedure is simple and the results are permanent. Cryostat sections of aldehyde-fixed routine preparations or paraffin sections of Carnoy-fixed tissues give the most satisfactory results. Mast cells are stained a strong red color that stands out distinctly from the surrounding tissues, so that they can be easily identified by simple microscopy. A double-staining technique, first for protease and subsequently using Alcian Blue, showed that as progressive protease staining occurs, the alcianophilia of mast cells is lost. This procedure demonstrated that mast cells in the mucosa of human gut generally required longer incubations to develop protease staining than in other connective tissue sites. In post-mortem tissues, mast cells retain their protease activity well and so can be demonstrated in cryostat sections of aldehyde-fixed material, giving a more complete picture than with Alcian Blue. The synthetic substrate D-Val-Leu-Arg-MNA can be recommended for routine identification of mast cells in human tissues.     

Mast cells in the rat gastric mucosa are not primarily responsible for PGD2 generation

The present study investigates the contribution of gastric mast cells on PGD2 generation in rat gastric mucosa. Cold-restraint induced stress or i.v. carbachol injection methods were used for gastric mast cell degranulation. In 19 stressed, 15 carbachol-infused and 14 control rats, gastric mast cell counts and gastric mucosa PGD2 assay were performed. Gastric mucosal content of PGF2 alpha was also determined in carbachol infused and control rats. The mean number of gastric mast cells was significantly lower in stressed and carbachol infused than in control rats. Despite these differences in gastric mast cell counts, neither PGD2 or PGF2 alpha contents in the gastric mucosa were significantly different in mast cells degranulated rats than in control animals. These results suggest another source of PGD2 in the rat gastric mucosa other than mast cells.     

Hormones in the nucleus. Immunologically demonstrable biogenic amines (serotonin, histamine) in the nucleus of rat peritoneal mast cells

Using 1-ethyl-3(3-dimethyl-aminopropyl)-carbodiimide (EDAC) fixation and immunocytochemical confocal microscopic study, bright serotonin and histamine fluorescence appeared in the nucleus of rat peritoneal mast cells. In case of paraformaldehyde fixation, this was not observed. The phenomenon can be explained by the cross-linking effect of EDAC, which did not allow the efflux of biogenic amines from the nucleus. This means that biogenic amines are present in the nucleus of mast cells, and this is supported by the flow cytometric measurement data of the whole cell. Other hormones studied (triiodothyronine, insulin, and endorphin) were not present in the nucleus. Four pharmaca with biogenic amine-influencing character in the central nervous system were used for studying the relation between the external (surrounding and cytoplasmic) and nuclear biogenic amine content of mast cells. Fluoxetine, a serotonin reuptake inhibitor depleted nuclear as well as cytoplasmic serotonin content. Clorgyline, a MAO-A inhibitor, decreased cytoplasmic serotonin content and weakened nuclear serotonin fluorescence. The tryptophan hydroxylase inhibitor, para-chlorophenylalanine (PCPA), and the mast cell degranulator, Compound 48/80, reduced cytoplasmic serotonin content without influencing nuclear content. Histamine fluorescence was influenced solely by fluoxetine. The results show that nuclear 5-HT content is dependent firstly of serotonin uptake and reuptake. To our knowledge, this is the first exact report on the presence of non-steroid-type-receptor-transported hormones inside the nucleus of a cell.     

Prolonged exposure to hyperoxia increases perivascular mast cells in rat lungs.

Prolonged hyperoxia, as may be used to treat patients with severe hypoxemia, can lead to lung injury, respiratory failure, and death. Resident mast cells play important roles in regulating the lung response to changing environmental conditions, as evidenced by their roles in asthma and airway hyperresponsiveness. In this study we evaluated the effect of prolonged hyperoxia on the number and distribution of mast cells in the rat lung. In rats maintained in normoxia, mast cells were distributed primarily in the loose connective tissue surrounding large bronchioles and vessels of the lung. In rats exposed to normobaric hyperoxia for 72 hr, mast cell number in lung sections increased significantly, and mast cells were found preferentially accumulated around vessels throughout the lung. Notably, mast cells around smaller vessels were abundant in hyperoxic lungs but rare in normoxic lungs. Also, mast cells were increased in the pleura of lungs exposed to hyperoxia. These changes in mast cell number and distribution in response to hyperoxia were evident in aged (22-month-old) rats as well as young (3-month-old) rats. As mast cell-derived mediators have many effects, e.g., on vascular leak and vascular tone, positioning of increased mast cell numbers throughout the lung vasculature may be an important contributor to changes in lung function subsequent to persistent hyperoxia.     

Adriamycin Binds to the Matrix of Secretory Granules during Mast Cell Exocytosis

The antineoplastic drug adriamycin induces exocytosis in rat peritoneal mast cells followed by a significant uptake of the drug into the secretory granules. The drug is fluorescent, allowing visualization of its accumulation and binding to mast cell granules by fluorescence microscopy. At the same time, the well known inorganic dye ruthenium red was used as a probe because of its great affinity for heparin in the mast cell secretory granules as visualized by bright field microscopy. Competition between adriamycin and ruthenium red for binding to the negatively charged matrix of granules was demonstrated. Biochemical studies were also performed to confirm microscopic observations. Adriamycin may be of interest for studying mast cell secretion; it is not only a strong fluorescent dye for mast cell granules that are in communication with the extracellular space, but it also induces mast cell exocytosis.     

Cytofluorometric quantitation of 5-hydroxytryptamine in mast cells: an improved technique for the formaldehyde condensation reaction

A simple technique for the condensation of cellular 5-hydroxytryptamine (5-HT) with formaldehyde gas is described. The technique, which is especially suited for quantitative cytofluormetric studies, involves the generation of formaldehyde gas from dry paraformaldehyde in a closed reaction vessel with the addition of a measured quantity of water. The fluorescence yield of 5-HT was tested at various humidities. Optimal results were obtained with the addition of 100 mg water to a 1000 ml reaction vessel containing 6 g of dry paraformaldehyde. A major advantage of the method if the fact that the humidity during the reaction can be precisely controlled. The fluorescence yield of 5-HT, tested over a 50 day period showed excellent reproducibility. The stoichiometry of the reaction was tested by comparison of cytofluormetic data with that obtained by analysing the 5-HT content of pooled mast cells with an independent biochemical method. A highly satisfactory correlation (r = 0.96) was obtained within the range of 0.1 to 4 pg of 5-HT per cell. The limit of sensitivity of the cytofluorometric method was found to be of the order of 10(-13) g, and was determined by the fluorescence blank of the mast cells. This contributes to between 10 and 30 per cent of the total fluorescence emission from mast cells containing about 0.2 pg of 5-HT.     

新生大鼠雌激素注射后睾丸肥大细胞的变化

新生大鼠注射雌二醇后,睾丸肥大细胞于第30天可见到,细胞数量随年龄增长而增多,生后4－6个月,睾丸网附近仍可见大量肥大细胞。睾丸内的肥大细胞比皮肤内的结缔组织肥大细胞（CTMC）小而与小肠粘膜的粘膜肥大细胞（MMC）相近,AB－S染色后基本着蓝色,硫酸小檗碱荧光染色后呈现中等强度黄色荧光,结果提示,新生大鼠雌激素注射后睾丸内肥大细胞的增多可能与免疫过程有关,睾丸内肥大细胞与CTMC和MMC皆有所不同。     

Stochastic model for mast cell proliferation in culture of murine peritoneal cells

We recently identified two types of mast cell colonies derived from murine peritoneal cells: type 1 and type 2. Type 1 mast cell colonies consisted of berberine sulfate(+)- safranin(+) connective tissue-type mast cells (CTMC) and were derived from mature CTMC in the heaviest fraction obtained by Percoll density gradient centrifugation. In contrast, type 2 mast cell colonies consisted of alcian blue(+)- berberine sulfate(-)- safranin(-) mucosal mast cells (MMC) and were derived from immature progenitors in low density fractions. We replated a total of 60 type 1 and 60 type 2 mast cell colonies and examined their capability for producing secondary colonies. Although all of the primary colonies yielded secondary colonies, the replating efficiencies of individual colonies varied over a wide range. Cumulative distributions of secondary colonies from both type 1 and type 2 primary colonies could be fitted well by gamma distributions obtained by computer simulation. These findings are in agreement with the stochastic model for CTMC- and MMC proliferation. Cytological analyses of secondary colonies from primary type 1 colonies revealed heterogeneous distributions of alcian blue(+)- safranin(-)- berberine sulfate(-) mast cells, suggesting that transdifferentiation from mature CTMC to safranin(-)- berberine sulfate(-) mast cells is also governed by stochastic mechanisms.     

The importance of mast cells for the neutrophil influx in immune complex-induced peritonitis in mice

The role of mast cells in polymorphonuclear leukocyte (PMN) influx in Ag-antibody complex-induced peritonitis was evaluated in mast cell-deficient WBB6F1-W/Wv (W/Wv) mice and their normal littermates, WBB6F1-+/+ (+/+). Peritoneal cell influx was evaluated after i.p. injection of preformed immune complexes. The first significant elevation in the PMN count over PBS-treated controls in +/+ mice was observed 2 h after stimulation. During the period of maximum leukocyte concentrations (6 to 10 h), the increase in total cell count was 5-fold and in PMN 25-fold. In W/Wv mice the PMN influx started 2 h later than in the +/+ mice, and the maximum response (8 to 10 h) was only 50% of that in controls. Reconstitution of mast cells in W/Wv mice for 2 wk or more restored the PMN response to immune complexes. Mast cell release due to AG-antibody complexes was evaluated by measuring fluorescence intensity after berberine sulfate staining for heparin in mast cells from unstimulated as well as stimulated +/+ mice. There was a significant decrease in fluorescence intensity as early as 15 min after stimulation. By 30 min the fluorescence intensity had declined by 65%. This indicates extensive mast cell release that started before PMN mobilization. These experiments demonstrate that mast cells make a significant contribution to immune complex-induced inflammation.     

Subcellular localization of brain mast cell histamine in developing rat

The intracerebroventricular administration of compound 48/80 or polymixin B to rats 0 to 60 days old, produced a decrease both in the histamine which sediments in the crude nuclear fraction, as well as in the number of mast cells in the brain. In contrast, the histamine-releasers did not affect histamine levels in subcellular fractions where neuronal histamine is found. Once released, histamine disappeared rapidly (t 1/2 = 3.8 min). In untreated animals and in those treated with histamine releasers, the number of mast cells/g in the whole brains of developing rats and in the cerebral regions of adult rats showed a close correlation with the histamine levels in the crude nuclear fraction. The content of histamine per mast cell in adult rat brain was estimated to be about 13 pg/cell. Histologic examination of the subcellular fractions revealed the presence of intact mast cells in the crude nuclear fraction obtained from untreated animals, and of degranulated mast cells in the same fraction obtained from animals treated with histamine releasers. The mast cell contribution to adult rat brain histamine levels was about 22%. Our results strongly support that most of the histamine which sediments in the crude nuclear fraction of the rat brain is located in mast cells. Determination of histamine in the crude nuclear fraction and in the supernatant of this fraction is proposed as an easy way for identifying the cellular pool altered by any treatment affecting brain histamine levels.     

从甲状腺肥大细胞探讨胎儿器官肥大细胞的差异

研究肥大细胞在人胎儿甲状腺发育中数量、分布及组化性质的改变,以探讨胎儿器官发育中肥大细胞的差异。取45例不同胎龄的人胎甲状腺石蜡切片做甲苯胺蓝染色和阿尔辛蓝－－藏红染色,并测定肥大细胞的临界电解质浓度值及进行硫酸小蘖硷荧光染色。结果显示：3月龄胎儿甲状腺内开始出现肥大细胞,数量极少,主要分布在被膜及小叶间结缔组织内,甲苯胺蓝染色肥大细胞颗粒呈淡紫蓝色,阿尔辛蓝－－藏红染色呈蓝色,临界电解质浓度值较低,硫酸小蘖硷染色未见显黄色荧乐的肥大细胞,从3月龄到足月随着胎龄增长,肥大细胞数量缓慢增多,8月龄时肥大细胞经甲苯胺蓝染色,其颗粒呈紫红色,阿尔辛蓝－－藏红染色出现少量含红色和红蓝混合染色颗粒的肥大细胞,临界电解质浓度值偏高,可见少量显黄色荧光的肥大细胞,结果表明：在人胎儿3月龄时甲状腺发育中开始出现肥大细胞,但随胎儿发育肥大细胞的组化性质改变不明显。     

Mast cells in normal and sectioned peripheral nerve

Summary An investigation is reported on the properties and quantitative distribution of mast cells in normal and sectioned peripheral nerve. A considerable number of mast cells has been found in the epineurial connective tissue in normal rats, as well as scattered mast cells in the endoneurium. After nerve section there was an about five-fold increase in the number of endoneurial mast cells throughout the distal part of the sciatic nerve.The mast cell granules in normal and sectioned nerve showed the same histochemical properties as mast cell granules in other tissues, i.e. strong toluidine blue metachromasia resistant to alcohol dehydration, and persistence of dye binding and metachromasia at pH below 1. Furthermore, the metachromasia is unaffected by extraction with chloroform and methanol prior to staining. The metachromatic component of the mast cell granules can be differentiated by these properties from other metachromatic structures in normal and sectioned nerve. The significance of the findings is discussed, in particular the possible relation of endoneurial mast cells to the degradation of myelin. Acknowledgements. The authors are indebted to Miss Kristina Müntzing for skilful technical assistance.     

Number, fixation properties, dye-binding and protease expression of duodenal mast cells: comparisons between healthy subjects and patients with gastritis or Crohn’s disease

Summary There is an accumulation of evidence to suggest that mast cells may play a key role in gastrointestinal inflammation. We have investigated the numbers and heterogeneity in staining properties of mast cells in biopsies of the duodenum of normal subjects (n = 10), and of normal duodenum from patients with Crohn’s disease of the ileum and/or colon (n = 7) or with Helicobacter-associated gastritis of the antrum/corpus (n = 6). In normal donors, two subsets of mast cells, one located in the duodenal mucosa and the other in the submucosa, were clearly distinguished by their morphology and dye-binding properties. Whereas submucosal mast cells stained metachromatically with Toluidine Blue after neutral formalin fixation and emitted a yellow fluorescence after staining with Berberine sulphate, those in the mucosa were invisible using these stains. In patients with gastritis or Crohn’s disease, there were marked changes in the numbers of mucosal mast cells compared with control subjects, even though the duodenal biopsies were from apparently uninvolved tissue. Gastritis was associated with increased mucosal mast cell numbers (controls: 187 ± 23 cells mm−2; gastritis: 413 ± 139 cells mm−2; p = 0.0004), but mean mucosal mast cell counts in the uninvolved duodenum of Crohn’s patients were actually decreased (34 ± 30 cells mm−2, p = 0.0147). The clear differentiation between mucosal and submucosal mast cells on the basis of metachromasia with Toluidine Blue was not seen in biopsies from the patients with gastritis or Crohn’s disease. Previous studies which have suggested that there are no distinct mucosal and submucosal mast cell subsets in the human intestine may, therefore, have been affected by the use of tissue from diseased subjects. Heterogeneity in the expression of mast cell tryptase and chymase was seen by immunohistochemistry using specific antibodies, but the relative numbers of mast cell subsets were critically dependent on the methods used. Using a sensitive staining procedure, the majority of mucosal mast cells stained positively for chymase as well as for tryptase, an observation confirmed by immunoelectron microscopy and immunoabsorption studies. Our findings suggest that early stages in intestinal inflammation may be reflected in changes in mast cell numbers and in their staining properties, and call for a reappraisal of mast cell heterogeneity in the human intestinal tract This revised version was published online in November 2006 with corrections to the Cover Date.     

Green fluorescent protein-based system for analysis of E-selectin-mediated adhesion

Numerous cell-based or cell-free systems for study of selectin adhesion use radiolabeled tracers. However, in addition to handling problems associated with the use of radioisotopes, these assays have difficulty relating a number of counts to a number of adherent cells. Here, we describe an assay that uses the natural fluorescence of the green fluorescent protein (GFP) to measure binding of cells to E-selectin. We elaborated an adhesion system composed of a cell monolayer expressing E-selectin ligand to which monodispersed fluorescent Chinese hamster ovary (CHO) cells expressing E-selectin are added. Due to GFP autofluorescence, adhered cells can be easily distinguished from cell monolayers by fluorescence microscopy, and adhesion can be measured by cytofluorometry. We applied this GFP-based adhesion assay to measure the adherence of a pancreatic tumor cell line and found that the binding parameters of these cells satisfy a number of E-selectin-specific criteria.     

Single-locus control of the mast cell population in mouse skin

The number of mast cells in connective tissue from dorsal skin varied markedly among mouse strains. Inbred strains of mice were typed into three groups, high (NC and NZB mice), low (B6, B10, and BALB/c mice), and intermediate (C3H/He and DBA/2 mice), by their mast cell content in the skin. However, the strain differences in the number of mast cells was marginal at the age of weaning but became distinct with age. This could be explained mainly by the frequently observed clustering of mast cells in adult NC and NZB mice and the rarely observed clustering in younger mice as well as in adult B10 and BALB/c mice. The breeding experiment revealed that the difference in the number of mast cells between NC and B10 mice was controlled by a single autosomal dominant locus, for which we propose the designation Mcr (mast cell regulator). The role of the Mcr locus with regard to the frequency of the mast cell population in connective tissue is discussed.