Modifications in the gills of hill stream Moth catfish, Hara hara (Erethistidae, Siluriformes): A light and scanning electron microscope investigation.

Present study reports significant modifications in surface ultrastructure, histological organization, and histochemical localization of glycoproteins (GPs) in the gills of a hill stream catfish, Hara hara. Punctate microridges on free surface of epithelial cells covering gill arches, gill rakers, gill filaments and secondary lamellae are considered to provide adaptive plasticity to gills in relation to the environment inhabited by fish. Short and stout gill rakers are considered to prevent food particles to pass in opercular chamber along with respiratory current that could damage delicate gill filaments. Mucous goblet cells show presence of different classes of glycoproteins. GPs with oxidizable vicinal diols are considered to control acidity of acidic GPs. GPs with carboxyl groups have been implicated with defensive mechanism against microorganisms. GPs with O-sulphate esters are associated to trap and to lubricate food particles for easy swallowing. Taste buds on gill arches and gill rakers function to select palatable food particles. Occurrence of taste buds on the gill filaments is regarded significant adaptation to analyse the chemical nature of water. This study could play a significant role to understand adjustment of gills in the hill stream fish.

Clinical Implications of Goblet Cells in Dacryoadenosis and Normal Human Lacrimal Glands.

PURPOSE: The purpose of this study was to investigate an enlarged dacryoadenotic lacrimal gland and normal lacrimal glands for the presence of goblet cells (mucocytes). DESIGN: Retrospective clinicopathologic series. METHODS: An enlarged lacrimal gland (dacryoadenosis) without obvious histopathologic alterations was extensively evaluated histochemically, immunohistochemically, and ultrastructurally to detect the presence of goblet cells and to compare the findings with those in five normal lacrimal glands. RESULTS: Granular, zymogen-rich pyramidal acinar cells in normal glands predominated over a previously not reported subpopulation of nongranular, pale-staining cells in both dacryoadenotic and normal lacrimal glands. These cells histochemically stained positively with mucicarmine and Alcian blue. Immunohistochemical and electron microscopic evaluations established that there was a displacement or replacement of cytoplasmic gross cystic disease fluid protein-15 and CK 7-positive tonofilaments in the pale acinar cells by myriad mucus granules. The goblet cells constituted approximately 2% of the normal acinar cells and 5% of dacryoadenotic acinar cells. A depletion of myoepithelial cells and ectopic intra-acinar ductular cells were also observed in dacryoadenosis. CONCLUSION: Dacryoadenosis is caused by an increase in the number of acini without individual acinar cell hyperplasia. A normal cytologic feature of the lacrimal gland is the presence of acinar goblet cells that had been long overlooked; they are increased in number in dacryoadenosis. Intra-acinar ductular cells and the scattered loss of myoepithelial cells are other abnormalities in dacryoadenosis. The presence of lacrimal gland goblet cells may have physiologic implications for the precorneal tear film and its derangements as well as for the histogenesis of mucus-producing carcinomas.

Proteolytic and Opportunistic Breaching of the Basement Membrane Zone by Immune Cells during Tumor Initiation.

Cancer-related inflammation impacts significantly on cancer development and progression. From early stages, neutrophils and macrophages are drawn to pre-neoplastic cells in the epidermis, but before directly interacting, they must first breach the underlying extracellular matrix barrier layer that includes the basement membrane. Using several different skin cancer models and a collagen I-GFP transgenic zebrafish line, we have undertaken correlative light and electron microscopy (CLEM) to capture the moments when immune cells traverse the basement membrane. We show evidence both for active proteolytic burrowing and for the opportunistic use of pre-existing weak spots in the matrix layer. We show that these small holes, as well as much larger, cancer cell-generated or wound-triggered gaps in the matrix barrier, provide portals for immune cells to access cancer cells in the epidermis and thus are rate limiting in cancer progression.

Ultrastructural changes in colonic epithelial cells in a rat model of inflammatory bowel disease.

Inflammatory bowel disease (IBD) is a global, chronic intractable disease. The functions of drugs and food components have been evaluated in models of IBD induced by 2,4,6-trinitrobenzene sulfonic acid (TNBS). Here, we used transmission (TEM) and osmium-maceration scanning (SEM) electron microscopy to evaluate the ultrastructure of colonic epithelial cells in rat models of IBD induced by TNBS. Histological evaluation revealed that the intestinal crypts in the most regions of the IBD-model colons were deformed and we classified them as having high cell migration rates (HMIG). The remaining regions in the intestinal crypts retained a relatively normal structure and we classified them as having low cell migration rates (LMIG). Osmium-maceration SEM revealed the mucosal fluid flowing in spaces without secretory granules in crypt goblet cells of both HMIG and LMIG regions, indicating the depletion of goblet cell mucin that is found in patients with IBD. The Golgi apparatus in absorptive cells was stacked and curled in both regions. Osmium-maceration SEM showed membrane network structures resembling endoplasmic reticulum that were large and expanded in absorptive cells with HMIG rather than with LMIG regions in IBD-model colons. These findings indicated that endoplasmic reticulum stress is associated with susceptibility to IBD and that the effects of various agents can be evaluated according to endoplasmic reticulum stress revealed by using electron microscopy in models of IBD induced by TNBS.

Dietary squid ink polysaccharide induces goblet cells to protect small intestine from chemotherapy induced injury.

Gastrointestinal mucositis induced by chemotherapy is associated with alterations of intestinal barrier function due to the potential damage induced by anti-cancer drugs on the epithelial cells. Goblet cells, an important epithelial lining in the intestine, contribute to innate immunity by secreting mucin glycoproteins. Employing a mouse model of chemotherapy induced intestinal mucosal immunity injury by cyclophosphamide, we demonstrated for the first time that polysaccharide from the ink of Ommastrephes bartramii (OBP) enhanced Cyto18, which is a mucin expression in goblet cells. The up-regulation of mucins by OBP relied on the augmented quantity of goblet cells, but not on the changes in the ultrastructure of endoplasmic reticulum (ER). Our results may have important implications for enhanced immunopotentiation function of functional OBP on intestinal mucosal immunity against intestinal disorders involving inflammation and infection.

TNFR1-induced lethal inflammation is mediated by goblet and Paneth cell dysfunction.

Tumor necrosis factor (TNF) is a powerful activator of the immune system and a well-validated target for treatment of autoimmune diseases. Injection of TNF induces systemic lethal inflammation characterized by hypothermia, induction of multiple cytokines, and extensive damage to multiple organs. Previously, we reported that TNF-induced lethal inflammation is strictly TNFR1(P55)-dependent. We also uncovered a crucial role for P55 expression levels in intestinal epithelial cells (IECs), in which P55+/+ expression is sufficient to sensitize to TNF lethality in an otherwise fully protected P55+/- background. Here, we investigated the molecular mechanism that drives TNF toxicity in IECs. Unexpectedly, we found that the degree of TNF-induced enterocyte damage and apoptosis in IECs is equally strong in TNF-sensitive P55+/+ mice and TNF-resistant P55+/- mice. Our results suggest that P55+/+-induced signaling causes goblet and Paneth cell dysfunction, leading to severe epithelial barrier dysfunction. As a result, intestinal permeability and systemic bacterial spread are induced, causing lethal systemic inflammation. In conclusion, we identified P55-induced goblet and Paneth cell dysfunction as a crucial mechanism for TNF-induced systemic and lethal inflammation.

Morphology and ciliary motion of mucosa in the Eustachian tube of neonatal and adult gerbils.

The Eustachian tube is a small canal that connects the tympanic cavity with the nasal part of the pharynx. The epithelial lining of the Eustachian tube contains a ciliated columnar epithelium at the tympanic cavity and a pseudostratified, ciliated columnar epithelium with goblet cells near the pharynx. The tube serves to equalize air pressure across the eardrum and drains mucus away from the middle ear into the nasopharynx. Blockage of the Eustachian tube is the most common cause of all forms of otitis media, which is common in children. In the present study, we examined the epithelial lining of the Eustachian tube in neonatal and adult gerbils, with a focus on the morphological and functional development of ciliated cells in the mucosa. The length of the tube is ∼8.8 mm in adult gerbils. Scanning electron microscopy showed that the mucosal member near the pharyngeal side contains a higher density of ciliated cells and goblet cells than that near the tympanic side. The cilia beat frequency is 11 Hz. During development, the length of the Eustachian tube increased significantly between postnatal day 1 (P1) and P18. Scanning electron microscopy showed that the mucosa contained a high density of ciliated cells with a few goblet cells at P1. The density of ciliated cells decreased while the density of goblet cells increased during development. At P18, the mucosa appeared to be adult-like. Interestingly, the ciliary beat frequency measured from ciliated cells at P1 was not statistically different from that measured from adult animals. Our study suggests that the Eustachian tube undergoes significant anatomical and histological changes between P1 and P18. The tube is morphologically and functionally mature at P18, when the auditory function (sensitivity and frequency selectivity) is mature in this species.

Cell lineage identification and stem cell culture in a porcine model for the study of intestinal epithelial regeneration.

Significant advances in intestinal stem cell biology have been made in murine models; however, anatomical and physiological differences between mice and humans limit mice as a translational model for stem cell based research. The pig has been an effective translational model, and represents a candidate species to study intestinal epithelial stem cell (IESC) driven regeneration. The lack of validated reagents and epithelial culture methods is an obstacle to investigating IESC driven regeneration in a pig model. In this study, antibodies against Epithelial Adhesion Molecule 1 (EpCAM) and Villin marked cells of epithelial origin. Antibodies against Proliferative Cell Nuclear Antigen (PCNA), Minichromosome Maintenance Complex 2 (MCM2), Bromodeoxyuridine (BrdU) and phosphorylated Histone H3 (pH3) distinguished proliferating cells at various stages of the cell cycle. SOX9, localized to the stem/progenitor cells zone, while HOPX was restricted to the +4/'reserve' stem cell zone. Immunostaining also identified major differentiated lineages. Goblet cells were identified by Mucin 2 (MUC2); enteroendocrine cells by Chromogranin A (CGA), Gastrin and Somatostatin; and absorptive enterocytes by carbonic anhydrase II (CAII) and sucrase isomaltase (SIM). Transmission electron microscopy demonstrated morphologic and sub-cellular characteristics of stem cell and differentiated intestinal epithelial cell types. Quantitative PCR gene expression analysis enabled identification of stem/progenitor cells, post mitotic cell lineages, and important growth and differentiation pathways. Additionally, a method for long-term culture of porcine crypts was developed. Biomarker characterization and development of IESC culture in the porcine model represents a foundation for translational studies of IESC-driven regeneration of the intestinal epithelium in physiology and disease.

Ultrastructural and functional analysis of secretory goblet cells in the midgut of the lepidopteran Anticarsia gemmatalis.

Defoliation caused by Anticarsia gemmatalis larvae affects the commercial production of the soybean. Although regulation of the digestion of soybean components has become part of the suggested strategy to overcome problems caused by Anticarsia larvae, few studies have focused on the morphological and cellular aspects of Anticarsia intestinal tissue. We have therefore further analyzed the morphology and ultrastructure of the midgut of 5th instar larvae of A. gemmatalis. Dissected midgut was subjected to chemical or cryo-fixation and then to several descriptive and analytical techniques associated with both light and electron microscopy in order to correlate anatomical and physiological aspects of this organ. Histological analysis revealed typical anatomy composed of a cell layer limited by a peritrophic membrane. The identified lepidoptera-specific goblet cells were shown to contain several mitochondria inside microvilli of the goblet cell cavity and a vacuolar H(+)-ATPase possibly coupled to a K(+)-pumping system. Columnar cells were present and exhibited microvilli dispersed along the apical region that also presented secretory characteristics. We additionally found evidence for the secretion of polyphosphate (PolyP) into the midgut, a result corroborating previous reports suggesting an excretion route from the goblet cell cavity toward the luminal space. Thus, our results suggest that the Anticarsia midgut not only possesses several typical lepidopteran features but also presents some unique aspects such as the presence of a tubular network and PolyP-containing apocrine secretions, plus an apparent route for the release of cellular debris by the goblet cells.

Effect of esophagoplasty on structural reorganization of colon transplant.

We studied ultrastructural reorganization of the colon transplant in delayed period after esophagoplasty. It was found that during functioning of the artificial esophagus, a complex of adaptive and pathologic processes occurs in the mucosa. Focal sclerosis of the mucosa and slight epithelial degeneration with hyperplasia and hypersecretion of goblet cells were found in biopsy specimens with stenosis of the anastomosis. In case of colonopathy of the transplant, more pronounced epithelial degeneration and proliferation accompanied by abundant polymorphocellular stromal infiltration were seen. Deformation of the transplant was characterized by progressive atrophic and sclerotic reorganization of the mucosa. Goblet cells with ultrastructural signs of hypersecretion predominated in the population of epithelial cells of the colon transplant; oligomucus and poorly differentiated cell and colonocytes with signs of alteration and degenerative changes in cytoplasmic organelles were also found.

Effect of passive smoking on the ultrastructure of the nasal mucosa in children.

OBJECTIVES/HYPOTHESIS: Passive exposure to cigarette smoke has been implicated in a number of respiratory childhood disorders. Most studies concerning smoking were directed to its carcinogenic effect on the lungs. However, the effects of smoking on nasal respiratory mucosa have not been widely studied. The aim of the present study was, therefore, to study the ultrastructural changes in the nasal mucosa of a pediatric population exposed to passive smoking. STUDY DESIGN: The study included 20 children between the ages of 5 and 11 years, who were scheduled for tonsillectomy and at the same time had a positive history of prolonged exposure to household passive smoke. Another 10 children with a negative household smoking history were included as a control group. All children were nonatopic and with a negative family history of allergy. None of them had adenoids or infective rhinosinusitis. METHODS: At the time of surgery, a 1-mm(3) biopsy was taken was taken from the lower border of the inferior turbinate. The specimens were processed and examined with electron microscopy RESULTS: Examination of the nasal mucosa showed several ultrastructural changes. These included patchy loss of cilia, generalized loss of cilia, squamous metaplasia, hyperplasia of goblet cells and seromucinous acini, and vascular congestion. More severe changes were observed with longer passive exposures to cigarette smoke. The study did not disclose any evidence of ongoing allergic reaction or neoplastic transformations. CONCLUSIONS: Children exposed to passive cigarette smoke may develop several structural changes in the respiratory nasal mucosa with subsequent negative effects on its ciliary activity and mucociliary function. As a result of these effects, defense mechanisms of the nose may be ruined or lost, and those children may develop persistent sinonasal infections. Exposure of these children to passive smoking for longer periods of time may also induce other significant changes that were not detected in the present study.

Histochemical and ultrastructural observations of respiratory epithelium and gland in yak (Bos grunniens).

Submucous glands and epithelial mucous cells of yak (Bos grunniens) respiratory tract have been studied by a variety of histochemical methods and transmission electron microscopy for differentiating and characterizing serous and mucous cells. By light microscopy, the distribution, numbers of mucous cells, volume of mucous glands (Reid index), and the ratio of mucous cell to serous cell in the bronchial tree were measured with different staining. Histochemically, a majority of mucous cells, presented in the surface epithelium of bronchi and glands, secreted neutral and acid mucosubstances, only a few sulfated mucosubstances were present. No mucus-producing cells were observed from the terminal to respiratory bronchiolar level. Ultrastructurally, serous cells in glands of the lamina propria had two distinct forms: one type filled with many round dense secretory granules, plentiful RER and few other organelles, similar to other animals; the other type contained some oval mitochondrial and distended RER, the granules resembled the former. The mucous cells in gland were similar to that of epithelium, which containing abundant secretory granules with an eccentric core. The mucous cells of the surface epithelium differ from other animals in the structure and histochemistry of their secretory granules. Analysis of the size and distribution of the secretory granules and other organelles of serous cells suggested that differences represent different phases of a secretory cycle, not various populations of cell or granules.

Cigarette smoke total particulate matter increases mucous secreting cell numbers in vitro: a potential model of goblet cell hyperplasia.

Cigarette smoking is associated with chronic obstructive pulmonary disease (COPD)--a term encompassing chronic lung inflammation, chronic bronchitis and emphysema. Goblet cell hyperplasia is a characteristic feature of the lung epithelium in COPD patients contributing to the overproduction of airway mucus, including mucin MUC5AC. Using an in vitro model of differentiated lung epithelium we have investigated morphological and cellular changes in response to interleukin (IL)-13 (2.5-20 ng/ml), cigarette smoke total particulate matter (TPM; 0.31-20 microg/ml) and three mainstream cigarette smoke constituents: acrolein, formaldehyde and acetaldehyde (all at 0.001-1 microM) over 28 days during differentiation (agents replaced daily Monday-Friday). Control cultures of human bronchial epithelial cells (HBECs) underwent mucociliary differentiation producing a columnar epithelium containing goblet, ciliated and basal cells. Non-cytotoxic doses of IL-13 induced a significant increase in the percentage of MUC5AC positive cells. Using both flow cytometry and immunocytochemical techniques for identification of MUC5AC positive cells, TPM treatment induced an increase in MUC5AC positive cells, becoming maximal at 5 microg/ml. Acrolein treatment also increased the percentage of MUC5AC positive cells. However, formaldehyde or acetaldehyde had little effect. This study demonstrates that lung toxicants can induce a profound effect on cellular differentiation in an in vitro model of the human lung epithelium.

Histologic changes in the auditory tube mucosa of rats after long-term exposure to cigarette smoke.

PURPOSE: The aim of the study was to investigate the effect of cigarette smoke on the auditory tube and middle ear mucosa after long-term exposure (4 and 6 months). MATERIALS AND METHODS: Fifteen rats were divided into 3 groups. The experimental groups were exposed to cigarette in a smoking chamber for 4 and 6 months (n = 5 each). A control group (n = 5) was placed in the same chamber without exposure to cigarette smoke. Histologic changes of the auditory tube mucosa were observed through light and electron microscopes. Histologic changes of the middle ear mucosa were also observed through light microscopes. RESULTS: The histologic changes consisted of a proliferation of goblet cells and an increase of mucus secretion in auditory tube. Squamous metaplasia was paradoxically decreased according to the duration of exposure in auditory tube. The number of goblet cell was gradually increased according to the duration of exposure in the auditory tube and middle ear. CONCLUSIONS: Long-term passive smoke directly affects the auditory tube and middle ear mucosa. Histologic changes of auditory tube mucosa consisted of goblet cell proliferation and excessive mucus secretion.

[Normal human bulbar conjunctiva on confocal microscopy in vivo].

OBJECTIVE: To analyze the morphology of human bulbar conjunctiva by in vivo laser scanning confocal microscopy. METHODS: This research was a cross-sectional study. From February to July 2008, 50 eyes of 50 healthy subjects were enrolled in this study. They had no history of ocular trauma, infection or contact lens wear and had no found after routine slit-lamp examinations. In vivo laser scanning confocal microscopic examinations were performed on the superior, inferior, nasal and temporal bulbar conjunctiva and the images were recorded. The morphology of bulbar conjunctiva was analyzed and the density of epithelial cells, dendritic cells and goblet cells were calculated. One-way analysis of variance (ANOVA) was used to compare the means of epithelial cell densities in different layers and goblet cell densities in different positions. Subsequently the datum between two groups were analyzed by least significant difference (LSD). RESULTS: Superficial epithelial cells of bulbar conjunctiva were characterized as large loose-arranged cells with a hyporeflective nucleus. The mean density is (1643 +/- 206) cells/mm(2). Intermediate epithelial cells were captured with features of oval small tight-arranged cells with a punctiform hyperreflective nucleus. The mean density is (4693 +/- 228) cells/mm(2). Basal epithelial cells appeared to be polygonal and regular-arranged within hyperreflective cell borders. The mean density is (4420 +/- 230) cells/mm(2). There was a significant difference among three kinds of conjunctival epithelium (F = 1160.312, P = 0.000). The presumed goblet cell was defined as a large hyperreflective oval-shaped cell with relatively homogeneous brightness, crowded in groups or mainly dispersed. The mean density is (432 +/- 72) cells/mm(2). The dendritic cell appeared to be hyperreflective corpuscular particles with dendritic processes scattered among conjunctival epithelial cells. The mean density is (22 +/- 25) cells/mm(2). The basement membrane, a prominent hyperreflective band, separated epithelial cells from subepithelial structure. Bulbar conjunctival substantia propria, beneath the basement membrane, was mainly composed of highly vascularized, loose connective tissues which were irregularly arranged fibers or a network of fibers, punctiform hyperreflective immune cells and sharp flows of blood vessels. CONCLUSION: In vivo laser scanning confocal microscopy is a useful tool in the analysis of the bulbar conjunctival morphology, which provided a fast and noninvasive method for the diagnosis of ocular surface diseases.

The ets-domain transcription factor Spdef promotes maturation of goblet and paneth cells in the intestinal epithelium.

BACKGROUND & AIMS: Stem cells within the intestinal epithelium generate daughter cells that undergo lineage commitment and maturation through the combined action of the Wnt and Notch signaling cascades. Both pathways, in turn, regulate transcription factor networks that further define differentiation toward either enterocytes or 1 of 3 secretory cell lineages (Paneth, goblet, or enteroendocrine cells). In this study, we investigated the role of the Wnt-responsive, Ets-domain transcription factor Spdef in the differentiation of goblet and Paneth cells. METHODS: The in vivo function of Spdef was examined by disrupting the Spdef gene in mice (Spdef(-/-) mice) and analyzing the intestinal phenotype using a range of histologic techniques and DNA microarray profiling. RESULTS: In accordance with expression data, we found that loss of Spdef severely impaired the maturation of goblet and Paneth cells and, conversely, led to an accumulation of immature secretory progenitors. Spdef appears to positively and negatively regulate a specific subset of goblet and Paneth cell genes, including Cryptdins, Mmp7, Ang4, Kallikreins, and Muc2. CONCLUSIONS: Spdef acts downstream of Math1 to promote terminal differentiation of a secretory progenitor pool into Paneth and goblet cells.

Allergic and idiopathic rhinitis: an ultrastructural study.

Nasal hyperreactivity is one of the most important underlying mechanisms in both allergic (AR) and idiopathic rhinitis (IR). In order to study the pathomorphological changes in this entity, tissue samples from patients with AR, IR, and from patients without chronic inflammation were taken during nasal surgery. Primary antibodies against Substance P (SP), calcitonin gene-related peptide (CGRP), and endothelial nitric oxide synthases (NOS III) were applied and the immunocomplexes were visualized by immunocytochemistry. The nasal mucosa of patients with AR and IR showed similarities on the ultrastructural level. Neurogenic inflammation was indicated by a strong innervation pattern with sensory nerve fibers containing SP and CGRP. We could show that extensive edema and cellular infiltration might be characteristic for AR. On other hand there was no evidence of eosinophilic or NO involvement in IR. Finally, on the ultrastructural level, AR and IR showed many similarities. Based on these findings anti-inflammatory therapy modalities could be recommended for both types of rhinitis.

Morphometric and ultrastructural comparison of the olfactory system in elasmobranchs: the significance of structure-function relationships based on phylogeny and ecology.

This study investigated the relationship between olfactory morphology, habitat occupancy, and lifestyle in 21 elasmobranch species in a phylogenetic context. Four measures of olfactory capability, that is, the number of olfactory lamellae, the surface area of the olfactory epithelium, the mass of the olfactory bulb, and the mass of the olfactory rosette were compared between individual species and groups, comprised of species with similar habitat and/or lifestyle. Statistical analyses using generalized least squares phylogenetic regression revealed that bentho-pelagic sharks and rays possess significantly more olfactory lamellae and larger sensory epithelial surface areas than benthic species. There was no significant correlation between either olfactory bulb or rosette mass and habitat type. There was also no significant difference between the number of lamellae or the size of the sensory surface area in groups comprised of species with similar diets, that is, groups preying predominantly on crustaceans, cephalopods, echinoderms, polychaetes, molluscs, or teleosts. However, some groups had significantly larger olfactory bulb or rosette masses than others. There was little evidence to support a correlation between phylogeny and morphology, indicating that differences in olfactory capabilities are the result of functional rather than phylogenetic adaptations. All olfactory epithelia exhibited microvilli and cilia, with microvilli in both nonsensory and sensory areas, and cilia only in sensory areas. Cilia over the sensory epithelia originated from supporting cells. In contrast to teleosts, which possess ciliated and microvillous olfactory receptor types, no ciliated olfactory receptor cells were observed. This is the first comprehensive study comparing olfactory morphology to several aspects of elasmobranch ecology in a phylogenetic context.

Morphological regional differences of epithelial cells along the midgut in Diatraea saccharalis Fabricius (Lepidoptera: Crambidae) larvae / Diferenças morfológicas regionais das células epiteliais ao longo do intestino médio de larvas de Diatraea saccharalis Fabricius (Lepidoptera: Crambidae)

The sugarcane borer, Diatraea saccharalis Fabricius, is a pest to sugarcane and many other crops. This work aims to characterize morphological variability in the epithelial cells (columnar, goblet and regenerative) along the midgut of D. saccharalis larvae. Fragments of the midgut (anterior, middle and posterior regions) were fixed and processed by light and scanning electron microscopy. There are both cytochemical and ultrastructural differences in the morphology of the epithelial cells, depending on their localization along the midgut. The apical surface of columnar cells shows an increase in both number and size of the apical protrusions from the anterior to the posterior midgut regions. There is an increase in the amount of PAS-positive (Periodic Acid-Schiff Reaction) granules detected in the cytoplasm of both the columnar and regenerative cells, from the anterior to the posterior region. The goblet cell apical surface is narrow in the anterior region, and enlarged in the posterior midgut; the chamber's cytoplasm extrusion are small and thin at the apical cavity surface, being thicker, longer and more numerous at the basal portion of the cavity. Our results suggest that the sugarcane borer midgut has two morphologically different regions, the anterior and the posterior; the middle region is a transitional region.

A broca da cana, Diatraea saccharalis Fabricius, é uma praga da cana-de-açúcar e outras plantações. O objetivo deste trabalho foi caracterizar variações morfológicas nas células epiteliais (colunares, caliciformes e regenerativas) ao longo do intestino médio de larvas de D. saccharalis. Fragmentos do intestino médio (anterior, mediano e posterior) foram fixados e processados para microscopia de luz e eletrônica de varredura. Existem diferenças morfológicas citoquímicas e ultra-estruturais nas células epiteliais, dependendo da sua localização no intestino médio. A superfície apical de algumas células colunares exibe projeções citoplasmáticas que aumentam em número e volume da região anterior para a posterior do intestino médio. Existe aumento dos grânulos PAS-positivos (Reação de Schiff) no citoplasma apical das células colunares e regenerativas, da região anterior para a posterior. A câmara das células caliciformes, na região anterior do intestino médio, mostra seu ápice estreito, enquanto que na posterior essa porção da câmara é alargada; as evaginações citoplasmáticas da câmara são pequenas e finas no ápice, sendo numerosas, longas e mais espessas na porção basal. Os resultados sugerem que o intestino médio da broca da cana apresenta duas regiões morfologicamente distintas, a anterior e posterior; a região mediana é uma região de transição.