Gastric Surface Epithelium Research Articles

Histochemical reactivity of peanut lectin-horseradish peroxidase conjugate.

A peanut lectin-horseradish peroxidase (PL-HRP) conjugate has been applied to histochemical staining of paraffin sections of various mouse organs. The PL-HRP conjugate has selectively reacted with secretory bodies, the Golgi zone, and the apical cell surface in various cell types. Some positive sites, including lingual and tracheal serous glands, Brunner's glands, and the brush border of the proximal straight nephron, contained periodic acid-Schiff (PAS)-positive glycoconjugate with no affinity for basic reagents. The stored secretion in these sites was interpreted as containing neutral glycoprotein with terminal galactose residues which could, in part at least, account for the PAS reactivity. Duodenal goblet cells, which exhibited basophilia attributable to sulfate esters, also bound PL-HRP. As the binding was affected by prior sialidase digestion, the secretory glycoprotein in the duodenal goblet cells was judged to contain oligosaccharides with sulfate esters and terminal galactose uncapped by sialic acid. All sites known from their basophilia to form sialomucin failed to stain with the PL-HRP conjugate, but consistently gained reactivity following sialidase digestion and were inferred, therefore, to possess glycoproteins with oligosaccharide side chains containing subterminal galactose and terminal sialic acid. Lingual mucous glands, known to secrete a mucosubstance with basophilic properties indicative of the presence of sulfate esters but not sialic acid, stained with PL-HRP only after sialidase digestion and, accordingly, were reinterpreted as containing both sulfate esters and terminal galactose-sialic acid dimers. Staining of gastric surface epithelium demonstrated a srongly PAS-reactive neutral glycoprotein, and that of goblet cells in the cecum disclosed PAS-positive sulfated glycoprotein. The latter two sites lacked PL-HRP affinity without or with prior sialidase treatment and apparently possessed neither terminal galactose residues nor galactose-sialic acid dimers. PL-HRP affinity was observed exclusively in the Golgi cisternae of some epithelial cells, thus indicating that galactose occurs transiently as a terminal residue in this site. A few histologic sites, such as pancreatic and gastric zymogen cells and renal tubules, were devoid of both PAS reactivity and basophilia indicative of the presence of complex carbohydrate but stained strongly with the PL-HRP conjugate by means which are not understood. Galactose in the PL-HRP solution blocked or reversed the PL-HRP binding in most of the structures with an affinity for the conjugate, supporting the conclusions that the reagent is specific for galactosyl residues.

Morphology and Histochemistry of Non-Tumorous Gallbladder Epithelium. A Series of 103 Cases

One hundred and three gallbladders were excised from 81 female and 22 male patients. Different non-tumorous morphologic and histochemical changes and their frequency were studied in these gallbladders and in their various components. Histochemical methods were used to visualize sulphated, non-sulphated acid, and neutral mucins. Sulphated mucin predominated in normal columnar epithelium and in the glands of the neck region, whereas non-sulphated acid mucin and neutral mucin predominated in goblet cell areas, in superficial gastric-type epithelial areas and in antral-type glands. Goblet cells were present in 67 specimens, enterochromaffin cells in 42, superficial gastric-type epithelium in 16, antral-type glands in 40, antral-type mucosa in 8 and intestinal-type mucosa in one specimen. Goblet cells, enterochromaffin cells, and gastric surface epithelium columns appeared initially in the surface portions of the folds. No relationship was established between the degree of metaplasia, the age of the patient, the duration of symptons, and the severity of illness.

Phagocytosis of cells in the gastric surface epithelium of the rat

Gastric surface epithelial cells (SEC) from fed rats, from rats fasted for 16 h and from mucosae exposed in an ex-vivo chamber to 16 mM aspirin for 5 min were examined by transmission electron microscopy. SEC have the capability to phagocytose adjacent epithelial cells and parietal cells. Phagocytosis is rare in mucosae from fasted animals but common in fed animals or after brief exposure to aspirin. Phagocytic capabilities are not restricted to the progenitor zone but exist throughout the surface epithelium. Phagocytosis may provide a mechanism for the removal of damaged or senescent cells from the surface epithelium.

Goblet Cells, Enterochromaffin Cells, Superficial Gastric-Type Epithelium and Antral-Type Glands in the Gallbladder

From a material derived from routine investigations, 40 gallbladder specimens were selected in which metaplastic cells had been observed. All the cholecystectomies were performed for gallstones. Of the patients 6 were male and 34 female. The mean age was 51.2 years. 36 specimens revealed goblet cells, enterochromaffin cells were found in 22, antral-type (pseudopyloric) glands in 23 and islands of gastric surface epithelium in 15 specimens. Histochemical methods to visualize sulphated, non-sulphated acid and neutral mucins were used. Ordinary gallbladder epithelium showed a predominance of sulphated mucosubstance. Sporadic goblet cells usually occurred in so-called goblet cell areas which, if small, were located in the tops of folds and only when larger also in the deeper parts of folds. As the goblet cell area enlarged, the relative proportion of sulphated mucin diminished and correspondingly non-sulphated acid mucin increased, while neutral mucin was noted both in the goblet cells and in the intervening columnar cells. In 20 specimens there were enterochromaffin cells in the goblet cell areas while only 2 specimens revealed enterochromaffin cells outside the goblet cell area. The glands outside the neck region of the gallbladder resembled gastric antral glands in their general architecture and in the appearance of individual cells. A part from frequent enterochromaffin cells (in 12 specimens) the glands are composed of mucous cells. The glandular cells contained sulphated mucin, non-sulphated acid and neutral mucin chiefly in the peripheral parts of glandular cells. In the gallbladders there were numerous abnormalities in some areas: heavy mucous secretion, goblet cells, enterochromaffin cells and superficial gastric-type epithelial spots were seen chiefly in the upper parts of folds, while proliferation of antral-type glands occurred in the basal parts. It is probable that some common pathological factors are responsible for the frequent simultaneous appearance of different types of metaplasia.

The effects of acetic and acetylsalicylic acids on the appearance of the gastric mucosal surface epithelium in the scanning electron microscope.

Acetic and acetylsalicylic acids have previously been found to increase the gastric mucosal permeability to ions. It has been suggested that this effect is due to cellular swelling caused by intracellular accumulation of the ionized acids. In an attempt to verify this hypothesis, specimens from both normal mucosae and from mucosae irrigated with solutions of either acetic or acetylsalicylic acid were studied in the scanning electron microscope. The normal cells appeared polygonal and closely attached. The acid-treated cells generally were swollen, and the intercellular junctions appeared incompletely broken. The result thus supported the hypothesis.

Enzyme cytochemistry of the abraded gastric surface epithelium. An aid in the diagnosis of early atrophic gastritis and focal intestinal metaplasia.

Enzyme cytochemistry of the abraded gastric mucosa was here developed as a new procedure and applied to the study of atrophic gastritis. This new technic consists of determining 5 enzymes in the superficial epithelium of the gastric mucosa, abraded by conventional cytologic brush technic—namely, alkaline phosphatase, acid phosphatase, leucine amino peptidase, lactic acid dehydrogenase and diphosphopyridine nucleotide diaphorase. Enzyme cytochemistry of the abraded surface epithelial cells was correlated, in 49 individuals, with the histology and cytology of the gastric mucosa, as obtained by gastric suction biopsy and conventional cytologic technic. In addition, in 31 of these patients, enzyme histochemistry of the gastric surface epithelium, obtained by gastric suction biopsy, was studied and correlated with enzyme cytochemistry of the smears of the abraded surface epithelium of the stomach. The results obtained indicate similar yields of cytochemical and histochemical methods in individuals with normal gastric mucosa and chronic superficial gastritis. However, enzyme cytochemical study of the abraded mucosa appears to be superior to histologic and enzyme histochemical examination of the gastric suction biopsy specimens in recognizing the early atrophic lesions of the gastric mucous membrane. These manifest themselves by positive reactions of the abraded surface epithelium for acid phosphatase, lactic acid dehydrogenase and diphosphopyridine nucleotide diaphorase. Enzyme cytochemistry is especially important in diagnosing the focally distributed intestinal metaplasia, which is often missed in gastric suction biopsy. This can be easily recognized by strongly positive reactions of the abraded surface epithelium for alkaline phosphatase and leucine amino polypeptidase. In view of the relation existing between the foci of intestinal metaplasia and development of gastric cancer in this area such a recognition may be significant in the followup of patients presenting this type of lesion.

Morphologic and histochemical demonstration of protein in gastric surface epithelium in protein-losing gastropathies.

Protein droplets have been found in damaged gastric surface epithelium in various gastropathies, in the majority of which plasma protein loss into the gastric lumen is known to occur. The droplets, which are believed to contain plasma protein and hemoglobin, may represent the pathway by which plasma proteins are transported from stromal blood vessels through the mucosa into the gastric lumen. The significance of the hemoglobin in the droplets is not known, but significant leakage of this compound may also take place in gastropathies although this phenomenon has not been as well documented as the plasma protein loss.

Electrolyte Movement Across Canine Antral and Fundic Gastric Mucosa

Isosmotic HCl solutions containing a nonabsorbable dilution indicator were instilled into vagally denervated canine antral and fundic pouches to study the comparative rates of electrolyte flux across the gastric surface epithelium from these two areas. Similar changes occurred in both pouches but hydrogen loss, sodium gain, and fluid entry were two to three times greater in the antrum; potassium entry was 10 to 12 times greater. Measurement of surface area of two antral, one mixed, and one fundic pouch suggest an even greater difference between the relative rates of electrolyte movement across these two types of gastric surface epithelium. Neither a cationic exchange of hydrogen for sodium nor dilution and neutralization by entering bicarbonate can alone account for the hydrogen ion loss. A combination of mechanisms, some as yet unknown, appears more likely. This increased antral permeability may be related to the physiological inhibition of gastrin release and the increased susceptibility of the antral mucosa to acid-peptic ulceration. The present data suggest that a significant portion of potassium appearing in gastric juice collected from the whole stomach enters through some component of the gastric mucosa other than parietal cells.

Acid alcoholic brilliant cresyl blue stain for gastric and other mucins.

Some but not all samples of brilliant cresyl blue (6-methyl-7-dimethylamino-2-phenoxazin chloride) under C. I. No. 51010 in Conn's Biological Stains when dissolved at 1% level in 50–70% alcohol containing 1% concentrated (12 N) hydrochloric acid, stain (in 30 min) a wide variety of human and laboratory animal mucins blue black on an almost unstained background. The mucoprotein of the gastric surface epithelium and of the peptic gland neck cells of several species reacts strongly. A 16 hr 60° C methylation in 0.1 M methyl-sulfuric acid in methanol is required to block the staining of these gastric and some intestinal mucins, while 1–2 hr intervals suffice to prevent the staining of mast cells, cartilage and metachromatic sulfomucins generally. Saponification (1% KOH/70% alcohol, 20min) does not restore staining in either location group, indicating that sulfate mucins are probably reacting in both.

Enzyme histochemistry of chronic atrophic gastritis

In early chronic atrophic gastritis there appear patches of altered surface epithelium having the morphologic and histochemical characteristics of a regenerating mucosa. This suggests that prior injury to the neck and crypt areas of the normal gastric surface epithelium may have pathogenetic significance in the onset of this disease.

Gastric pepsin, mucus and clinical secretory studies. II. The role of the mucous barrier in the defense of the stomach vs. peptic ulceration. Carbohydrate histochemistry of gastric epithelial secretions in dog.

SummaryHistochemical methods specific for carbohydrate constituents distinguish a number of widely different entities in several types of gastric epithelial cells in the dog.The surface gastric epithelium reveals basophilia, indicating mucosubstances rich in both carboxyl groups (presumably sialic acid) and sulfate esters. The carboxyl‐type basophilia predominates in the superficial convolutions, and that attributed to sulfate is found in the foveolar walls. The strong reactivity with both the periodic acid‐Schiff (PAS) and the periodic acid‐para diamine (PAD) methods for vicinal‐hydroxyls indicates presence of hexose‐ or deoxyhexose‐rich mucosubstances in both of these areas. Susceptibility of basophilia to blockage by initial periodate‐meta diamine treatment points to presence of vicinal‐glycols in proximity of the acid groups in surface epithelium mucin. The surface epithelium in the pylorus differs slightly in that its secretion is less strongly basophilic.The mucous neck cells secrete an apparently neutral mucosubstance which differs from the surface epithelium in its lack of both PAD reactivity and basophilia. The parietal cells also form a diastase‐resistant, neutral, carbohydrate‐rich substance. The zymogen cells are abundant, deep in the glands of the cardiac portion and the body of the stomach, but less numerous in the intermediate zone. They contain apical granular secretion apparently rich in sulfated mucosubstances. Lack of reactivity toward vic‐glycol methods, resistance of alcianophilia or azurophilia to a previous periodate‐meta diamine sequence, and resistance of mixed diamine staining to previous periodate oxidation indicate absence of residues with unsubstituted adjacent hydroxyls (e.g., hexose or deoxyhexose), in this acid mucosubstance.The pyloric glands resemble mucous neck cells in their strong PAS staining and lack of PAD reactivity, but differ in that they show a weak staining indicative of sulfomucin.

Factors Influencing the Delayed Effect of Irradiation on Gastric Bioelectric Activity in Rat

In a previous report, an indirect effect of X-irradiation on gastric bioelectric activity was described in the rat (1). Normal gastric bioelectric activity in rat has been linked to sodium ion movement across the mucosa (2), and in the rabbit, at least, a similar sodium dependence of part of the gastric bioelectric current is known (3). However, little information is available on the factors influencing the irradiation effect on this ion transport system. That other factors may operate in conjunction with irradiation to inhibit electrical activity was suggested by a complex time course leading to the most severe depression in gastric bioelectric activity on the seventh to eighth postirradiation day. Little early effect was detectable, and the 7to 8-day minimum did not correlate well with the time course of other features of irradiation injury in the gastrointestinal tract of rats. Such injury, typical at higher X-ray doses, shows a 3-day critical time for biliary outpouring of sodium (4), and inhibition of normal ileal resorption of sodium is more marked at 67 hours than at earlier times (5). The time of bioelectric changes also seemed unrelated to the gastric epithelial surface renewal rate, which in nonirradiated rats has been estimated at 3 days (6). At similar and lower X-ray doses in the rat, several other kinds of change have been reported in the gastrointestinal tract, showing varying and in some cases overlapping time courses-for example, effects on motility (7, 8), on mucosal and intestinal weights and DNA (9, 10), on glucose oxidation (11), and on tissue cholinesterase (10). These findings suggest that certain of the irradiation effects might represent an end result of interactions at several tissue levels, as for example between extrinsic autonomic nerve tissue and the secretory epithelium, or between dietary factors and the epithelium. In the present report, dose sensitivity