Quantitative histochemistry of mucosubstance in tracheal epithelium of the macaque monkey

Experimentally applied irritants and chronic respiratory diseases appear to alter the amount and composition of secretory cell product in surface epithelium and submucosal glands of pulmonary airways. Previous methods used to quantify these changes have been very time-consuming or have not measured the same components of the airway wall. The present study describes a rapid, reproducible, and standardized automated method for quantifying secretory products. The tracheas from eight macaque monkeys were fixed with glutaraldehyde-paraformaldehyde, embedded in glycol methacrylate, serially sectioned at 2 microns, and histochemically stained to demonstrate neutral, sialylated, and sulfated mucosubstances in the cartilaginous, intercartilaginous, and membranous regions of both proximal and distal trachea. Volume densities were determined using an image analyzer and are expressed as volume of stained mucosubstance per unit surface area of epithelial basal lamina. Comparison of the automated method to manual point counting and evaluation of internal variance showed that the automated method had a twelve-fold increase in efficiency with no significant differences in measurements. After weighting the values of each region according to their anatomical contribution, the total secretory product (TSP) for the entire trachea was determined. Periodate-reactive acid material predominated (73%) in luminal surface epithelium, and neutral material predominated (78%) in submucosal glands. Surface epithelium contained 66% of the TSP. The greater contribution by surface epithelium and predominance of acid mucins there resulted in a TSP from the trachea that consisted of 59% acid material (most of which was sulfated) and 41% neutral material. The method proved to be a valid, reproducible, and rapid technique for evaluating variability in abundance of mucosubstances within airway epithelium.     

Carbohydrate histochemistry of the opossum submandibular and major sublingual glands.

Submandibular and major sublingual salivary glands of the opossum contain histochemically demonstrable neutral mucosubstances, nonsulfated acid musosubstances and sulfomucins. Sialomucins could not be demonstrated conclusively with the methods used in this study. Special serous cells of the opossum submandibular gland contained low concentrations of acidic mucosubstances but no appreciable concentration of neutral mucosubstances was seen. Sulfomucins were not observed in special serous cells. The mucous tubules of the submandibular gland contained high concentrations of neutral mucosubstances. No appreciable acidic mucosubstance was demonstrated in the submandibular gland mucous tubules. Unlike the mucous tubules of the submandibular gland, the major sublingual gland mucous tubules contained high concentrations of both neutral and acidic mucosubstances. The mucous tubules often contained sulfomucin-positive cells interspersed among cells that contained high concentrations of non-sulfated acidic mucosubstance. Marked staining of sulfated acidic mucosubstance was seen only in the major sublingual gland, in both the mucous tubules and in the seromucous demilunes. The seromucous demilunes contained both sulfated and non-sulfated acidic mucosubstances.     

Histochemistry of mucosubstances in the gallbladder epithelium of the chick embryo

Mucosubstances of epithelial cells of the chick embryo gallbladder were investigated by histochemical methods from days 12-21 of incubation (stages 38-46). On incubation day 14, only neutral mucins were detected; on day 15, neutral and sulfated mucosubstances were observed in the epithelial cells that invaginate the underlying mesenchyme. In the same sites, at day 16 of incubation, neutral, carboxylated and sulfated mucins were seen. From the 17th day of incubation until hatching, neutral, carboxylated and sulfated mucosubstances were present in the surface cells and in the cells lining the epithelial invaginations. During this period, the chemical characteristics of the secretory material are similar to those observed by Yamada and Hoshino (1972) in the fowl.     

Histochemistry of mucosubstances in the gallbladder epithelium of the chick embryo

Summary Mucosubstances of epithelial cells of the chick embryo gallbladder were investigated by histochemical methods from days 12–21 of incubation (stages 38–46). On incubation day 14, only neutral mucins were detected; on day 15, neutral and sulfated mucosubstances were observed in the epithelial cells that invaginate the underlying mesenchyme. In the same sites, at day 16 of incubation, neutral, carboxylated and sulfated mucins were seen. From the 17th day of incubation until hatching, neutral, carboxylated and sulfated mucosubstances were present in the surface cells and in the cells lining the epithelial invaginations. During this period, the chemical characteristics of the secretory material are similar to those observed by Yamada and Hoshino (1972) in the fowl.Dedicated to Professor Dr. T.H. Schiebler on the occasion of his 65th birthday     

Histology and histochemistry of the parotid and the principal and accessory submandibular glands of the little brown bat

The parotid and the principal and accessory submandibular glands of the little brown bat. Myotis lucifugus (Vespertilionidae), were examined using light microscopy and staining methods for mucosubstances. The parotid gland is a compound tubuloacinar seromucous gland. Parotid gland secretory cells contain both neutral and nonsulfated acidic mucosubstances. The principal and accessory submandibular glands are compound tubuloacinar mucus-secreting glands. They contain somewhat atypical mucus-secreting demilunar cells that often appear to be interspersed between mucous tubule cells. The mucous tubule cells in both the principal and accessory submandibular glands contain sulfonmucins. Demilunar cells of the principal submandibular gland contain moderate amounts of nonsulfated acidic mucosubstances, but the corresponding cells of the accessory submandibular gland contain considerable neutral mucosubstance with very little acid mucosubstance. Intercalated ducts composed of cuboidal or low columnar epithelial cells are present in all three glands. Striated ducts in all glands are composed of columnar cells whose apices bulge into the ductal lumina. Excretory ducts are composed of simple columnar epithelium, with occasional basal cells that suggest a possible pseudostratified nature. The cells of the excretory ducts also have bulging apices. All duct types contain apical cytoplasmic secretory material that is a periodic acid-Schiff positive, neutral mucosubstance. Ductal apical secretory material is more evident in intercalated and striated ducts than in excretory ducts.     

Ultrastructural carbohydrate cytochemistry of gastric epithelium

Synopsis On examination with ultrastructural methods for visualizing thevicinal glycols and acid groups of complex carbohydrates, the most superficial surface epithelium of the rat gastric corpus displayed biphasic mucous droplets consisting of a cortex of hexose-rich (i.e. periodate-reactive) neutral mucosubstance and an uncharacterized denser core plus monophasic droplets with the neutral mucosubstance. In many surface epithelial cells of the foveolae, the biphasic and monophasic droplets with the neutral mucosubstance intermingled in varying proportions with monophasic droplets showing uniform periodate reactivity, a variable degree of dialyzed ironbinding—demonstrative of acidic glycoconjugate, and high iron—diamine affinity—demonstrative of sulphomucin. Deep foveolar epithelium displayed only monophasic droplets, most of which contained acidic periodate-reactive complex carbohydrate. Underiying cells, designated isthmus cells, exhibited monophasic or occasional biphasic granules containing sulphated, hexose-rich mucosubstance. Nascent droplets or granules near the Golgi zone differed from the mature organelles in the distribution of the glycoconjugate. Mucous neck cells occupied a deeper stratum and displayed a uniform population of monophasic mucous droplets with a loose meshwork of neutral mucosubstance.Techniques for demonstrating hexoses ultrastructurally stained all Golgi cisternae in the mucigenic epithelium, showing increasing reactivity toward the maturing face. Distinctive cistemae with moderate reactivity in the Golgi complex of isthmus cells were interpreted as GERL. Acidic mucosubstances were visualized only in the inner, mature cisternae of the Golgi complex of cells storing acidic glycoconjugates, and not in cisternae interpretable as GERL.The apical plasmalemma of isthmus cells uniquely exhibited abundant sulphated glycoconjugate and that of parietal cells revealed a less prominent, periodic neutral mucosubstance. Lateral and basal plasmalemmae varied from unstained to slightly reactive; basement membranes showed moderate reactivity with methods for visualizing complex carbohydrates. Abundance of glycogen further characterized surface epithelial cells of the corpus and of some parietal cells     

Histochemical analysis of goblet cell mucins in the chick embryo colon

The histochemical characteristics of colonic epithelial mucins were investigated in the chick embryo. At the 14th day of incubation it was possible to demonstrate the presence of glycogen. At the 15th day a few epithelial cells showed the presence of neutral and sialylated mucins. On the 16th day, also sulfated secretory material was detectable together with neutral and sialylated mucins in cells with the typical shape of goblet cells. From the 17th day to the 20th day of incubation the two types of acid mucins appeared in some cells to be placed in distinct zones of the supranuclear cytoplasm. At the 21st day, neutral, sialylated and sulfated mucins were all present in the majority of goblet cells, which were found mainly in the epithelium lining the crypts.     

Histochemical investigations on the secretory cells in the oesophagogastric tract of the Eurasian green toad,Bufo viridis

The secretory cells of the oesophagogastric tract of the Eurasian toad, Bufo viridis, were examined using standard histochemical methods and lectin histochemistry. Two goblet cell types were found in the oesophageal epithelium, differing in their morphology and the histochemical features of the secretory granules. These contained mainly acidic glycoconjugates, both sulphated and carboxylated, and a small amount of pepsinogen. Type I goblet cells contained stable class-III mucosubstances, which were absent in Type II. No pluricellular oesophageal glands were found. The oesophagogastric junction had a superficial epithelium similar to that of the oesophageal epithelium, with alveolar pluricellular glands, secreting stable class-III mucins, and few oxynticopeptic cells. The gastric mucosa presented secretory cells both in the surface epithelium and in the gastric glands. Superficial and foveolar cells produced neutral mucins with Gal1,3GalNAc residues. Neck cells, oxynticopeptic cells and endocrine cells were found in the gastric glands. Neck cells produced stable class-III mucosubstances. A functional gradient was observed in the oxynticopeptic cells from the oral to the aboral fundus, with a decrease in pepsinogen secretion towards the aboral fundus and a possible increase in HCl secretion. In the pyloric mucosa, the oxynticopeptic cells disappeared and the glands produced only neutral mucins, without stable class-III mucosubstances.     

Histological,histochemical, and ultrastructural investigations on the gastrointestinal system of antarctic seals: Weddell seal (Leptonychotes weddellii) and crabeater seal (Lobodon carcinophagus)

The morphology of the principal sections of the gastrointestinal system of two Antarctic seals with different dietary habits, namely, the Weddell seal (Leptonychotes weddellii) and the crabeater seal (Lobodon carcinophagus), has been investigated. Histologically examined by light microscopy, the tissue layers of the gastrointestinal tract of both seals are almost identical to those observed in most other mammals and no major differences in principle organization could be found between the two seal species. The ultrastructure of the gastric and intestinal epithelial cells has been examined and is also closely comparable to that of these cells in other mammals; however, Paneth cells have not been found in our material. In general, therefore, adaptations of the gastrointestinal tract to the aquatic environment or the diet are not obvious at the morphological levels of organization studied. Histochemical differences are found between the two closely related species; mucins of the surface epithelium in the stomach of Weddell seals are highly sulfated, while those in the crabeater seal are not. Mucous neck cells in Weddell seals contain acid mucosubstances, while those of crabeater seals contain neutral ones. Goblet cells in the small and large intestine in Weddell seals contain both neutral and acid mucosubstances. Both mucin types are detected in the crabeater seal; however, the mucins of the colon in the crabeater seal are more highly sulfated than those in the Weddell seal. The ratio of globet cells to enterocytes in the large intestine of crabeater seals is higher than that in Weddell seals. © 1995 Wiley-Liss, Inc.     

The histological structure and histochemistry of the mucosa of the nasal conchae in geese,Anser anser

We investigated the histological structure and histochemistry of the nasal conchae of geese and compared these structures with those of other avian species. The rostral, middle and caudal conchae were dissected from the nasal cavity of eight geese, fixed in Carnoy’s solution and embedded in paraffin. The entrance of the rostral concha was lined by keratinized stratified squamous epithelium, which toward the middle concha was replaced by modified keratinized squamous epithelium, the deep layer of which opened into tubular glandular structures containing secretory epithelium on crypt-like invaginations. The lamina propria of the rostral concha contained numerous Grandry’s and Herbst corpuscles, which are pressure-sensitive receptors peculiar to waterfowl. The lamina propria of the middle concha contained solitary lymphoid follicles and lymphocyte infiltrations. The cartilaginous component of the middle concha was highly convoluted and resembled a spiral of two and a half scrolls, which were lined by pseudostratified columnar epithelium. We observed that unlike mammals, this epithelium contained mostly intraepithelial alveolar glands rather than goblet cells. The caudal concha was similar to the middle concha, but less convoluted. It was lined by olfactory epithelium and its lamina propria contained serous Bowman’s glands as well as olfactory nerve fibers. Histochemical examination demonstrated that while none of the conchae contained sulfated mucins, except for the cartilage, the intraepithelial glands of the rostral and middle conchae contained mostly carboxylated acidic mucin and some neutral mucin, and were thus of the mixed type. The outermost scroll of the spiral of the middle concha contained some periodate-Schiff stained mucins. Of the glands of the mucosa of the middle concha, the deep tubuloalveolar glands in the convex parts of the scrolls contained primarily acidic mucins, while the shallow intraepithelial alveolar glands in the concave parts of the scrolls contained primarily neutral mucins. Our findings indicate that the rostral and caudal conchae primarily have a sensory function and the middle concha participates in mucosal defense.     

Morphochemical analysis of epithelial mucosubstances in the gall bladder of the fowl (Gallus Domesticus)

Summary The epithelium of the fowl gall bladder have been reacted for a series of light microscopic stainings of mucosaccharide and protein histochemistry, in an attempt to characterize the epithelial mucosubstances. On the basis of the data of the present morphochemical analysis, the epithelial mucosubstances are concluded to be sulfated, carboxylated and neutral mucopolysaccharide-protein complexes. The cytophysiological significances of these mucosubstances have been briefly discussed.This investigation was supported in part by a Grant in Aid from the Takeda Science Foundation (Osaka, Japan).     

Variation in glycogen and mucins in the equine uterus related to physiologic and pathologic conditions

Histochemical stains were applied to six equine uterine biopsies representative of the physiologic breeding season, Spring and Fall transition, and Winter anestrus periods. These were compared with uterine biopsies from six mares with intrauterine urine pooling, eight mares used to study the uterine response to indwelling catheterization, and necropsy specimens from four pregnant mares at approximately 60 or 100 d of gestation. Alcian blue staining at pH 2.5 or 1.0 was used to identify the presence of carboxylated and sulfated acid mucins or only suflated acid mucins, respectively. Periodic acid-Schiff staining was used to identify neutral mucosubstances or glycogen, with or without prior diastase digestion. The uterine glands contained glycogen, which was most abundant during the physiologic breeding season. The luminal epithelial cells during the physiologic breeding season and Spring and Fall transition contained predominately carboxylated acid mucins. Carboxylated acid mucin secretion also was stimulated by indwelling catheterization and intrauterine urine pooling. It is hypothesized that secretion of carboxylated acid mucins by the endometrial epithelium may be elicited by hormonal or irritative/inflammatory stimuli, and it may be a protective response.     

Distribution and histochemical characterization of goblet cells in the nasal cavity of piglets

The present study was designed to compare the distribution of goblet cells and the histochemical composition of mucosubstances produced by these cells in the nasal cavity of piglets aged from 1 to 28 days. Serial transverse sections were stained to demonstrate neutral, acidic, and sulfated mucosubstances. Sections located at eight reference levels rostrocaudally in the nasal cavity and defined regions on these sections were used for goblet-cell counting. There was a nonhomogeneous distribution of goblet cells in the nasal cavity of piglets. A rostrocaudal increase in goblet-cell density was observed with the highest densities found in the ventral meatus and on the septum. There was no difference in this pattern of distribution according to age of the piglets. However, age-related differences were observed in the prevalence of goblet cells containing sialomucins, sulfomucins, or both. While sialomucins were prevalent at 1 and 14 days, sulfomucins predominated in the rostral half of the cavity at 28 days. Our results indicate a maturation of the products of secretion with aging in piglets. The affinity of infectious agents for sialylated glycoconjugates and the predominance of sialomucins in the nasal cavity of newborn piglets could account for their greater susceptibility to bacterial infection.     

The cephalic glands of Brazilian reptilia and amphibia. IV. Histology of labial, premaxillary, and Duvernoy's glands in the colubrid snake Oxyrhopus trigeminus

A study of the morphology of the salivary glands of the colubrid snake Oxyrhopus trigeminus showed the following: The acini of supralabial, infralabial, and premaxillary glands are formed by mucous and mucoserous cells; the tubules of Duvernoy's gland are formed by seromucous cells; and mucous cells produce neutral and acid mucosubstances, mucoserous cells secrete neutral and acid mucosubstances and protein, and seromucous cells have neutral mucosubstance and protein secretions.     

Structure and mucous histochemistry of the intestinal respiratory tract of the mud loach, Misgurnus anguillicaudatus (Cantor)

The straight intestinal tract of the mud loach Misgurnus anguillicaudatus was divided into an intestine and rectum which consisted of a mucosa (epithelial layer), lamina propria‐submucosa, muscularis and serosa. The intestine and rectum have shorter mucosal folds and a thinner wall. Extensive vascular capillary networks were present in the mucosa of the intestine and the rectum. The diffusion distance between the vascular capillaries and the lumen in the intestinal and rectal mucosal epithelium was about 11.2 μm (±1.12). The majority of the epithelial mucous cells contain acidic mucins although there are small amounts of a mixture of acidic and neutral mucins. The intestinal tract of M. anguillicaudatus is probably modified to suit its role of respiration for the deficient oxygen supply within their environment.     

On the harderian gland of the domestic duck (Anas platyrhynchus)

Summary The parenchyma of the Harderian gland of the domestic duck consists of numerous tubular terminal portions, lined by a simple columnar epithelium. Its secretory surface is increased by intratubular folds. Within the cytoplasm of the epithelial cells secretory granules are observed. Polysaccharides of different nature are demonstrated. Strikingly, all centrally located cells contain a periodate reactive mucin. The successive administration of the PAS reaction and of Alcian Blue reveals the coexistence of acid and neutral mucins in the same cells. A metachromatic reaction of the mucosubstances at pH 1.0 was observed and the presence of acid sulfated groups in the Harderian gland, as demonstrated byAlcian Blue at pH 0.5, thereby confirmed. There was no glycogen reaction.The author wishes to thank Prof. Dr. W. Kühnel for his assistance and introduction to the topic for his dissertation. His thanks also go to Prof. Dr. G. Petry, and Prof. Dr. E. Roosen-Runge of the University of Washington, Seattle, USA, for their interest and suggestions.     

Histochemical analysis of mucous cells in the epidermis of brown trout Salmo trutta L.

A histochemical study of the epidermal mucous cells of brown trout revealed that they contained both neutral and acidic mucosubstances which were diastase-resistant, PAS-reactive. Neuraminidase treatment, methylation and combined staining procedures suggested that the acidic nature of the mucins was due mainly to the presence of sialic-acid containing glycoprotein. These results augment data derived from biochemical analyses of the epidermal mucus of salmonid fish.     

Structure and carbohydrate histochemistry of the stomach in eight species of teleosts

The histology and carbohydrate histochemistry of eight teleostean stomachs are compared. Three gross anatomical types of stomachs are described and their shapes appear to correlate somewhat with feeding habits. Each type can be divided histologically into a corpus and pylorus. Gastric glands, containing only one cell type, occur in the copora of all species, but are present in the pylori of esocids only. As a single cell can produce both enzymes and hydrochloric acid such cells may be comparable to those of amphibians but not mammals. Lamina propria and submucosa are indistinctly separated in corpora but better defined in pylori by an intervening muscularis mucosa. The arrangement of the muscularis into inner circular and outer longitudinal layers is the opposite of that seen in the esophagus. Gastric mucous cells show species variations in localization of epithelial mucosubstances, which in broad terms are recognized as sulfomucins, sialomucins and neutral mucosubstances. A piscivorous diet does not appear to demand any particular type of carbohydrate. Within the Centrarchidae, gastric pit cells vary in carbohydrate content from only neutral mucosubstance to only weakly acidic sulfomucin; two species contain both types. A positive PAS reaction on the surface of gastric epithelial cells is suggestive of a striated border and thus possibly absorptive function. The absence of stomachs in some teleosts and the evolutionary and dietary significances are discussed.     

Regeneration of colonic mucosa in the rat

As part of a study of ulcer formation and healing, regeneration of colonic mucosa in rats was studied following placement of a surgical lesion. Alterations in mucosubstances and connective tissue were examined and their possible significance discussed. The sequence of events in healing was: (1) The mucosa adjacent to the lesion tipped into the lesioned area. The crypts in this mucosa became lined with cells which contained no mucus and had no striated borders. Later in the experimental period, these undifferentiated cells gave rise to cells containing carboxymucins. Cells containing sulfomucin, neutral mucin, or having striated borders arose from the carboxymucin cells. (2) An epithelial ledge of undifferentiated cells migrated onto a sulfated glycosaminoglycan, fibrous interface between necrotic and living tissue in the lesion. (3) Crypt formation began with the appearance of intraepithelial anlagen. (4) Crypts lengthened by a process of epithelial-connective tissue proliferation from the base of the crypt upwards. Following completion of connective tissue regeneration, crypts formed by invading the reestablished lamina propria. (5) The first mucous cells in the ledge contained carboxymucins. As crypt formation occurred, these cells gave rise to typical columnar absorptive cells, to cells containing sulfomucins, and to cells containing neutral mucins. (6) Lengthening of crypts ceased following the appearance of a sulfated acid glycosaminoglycan—collagenous layer deep in the submucosa.