scispace - formally typeset
Search or ask a question

Showing papers on "Apical cytoplasm published in 1980"


Journal ArticleDOI
TL;DR: It is concluded that there is a great deal of interspecies variability in the cellular morphology of the nonciliated bronchiolar epithelial cell of distal conducting airways in mammalian lung.
Abstract: Two morphologic characteristics have been used to define the nonciliated bronchiolar epithelial cell: (1) abundance of agranular endoplasmic reticulum (AER) and (2) numerous membrane-bound ovoid granules. In this study, we examined lobectomy specimens from three nonsmoking humans: one male (9.5 yr) and two females (62 and 43 yr) for comparison with lung specimens from mammalian species used as experimental models in lung research. Following fixation by airway infusion at constant pressure (20 cm), lung tissue was processed by a selective embedding technique and bronchioles of known anatomic location were studied by electron microscopy. Nonciliated bronchiolar epithelial cells of man contained numerous membrane-bound granules (averaging 6 per cell) in the apical cytoplasm and abundant granular endoplasmic reticulum (GER). AER was not observed. Granules averaged 0.3 μm in diameter and contained a fine granular matrix and parallel tubular arrays. After comparing these features in man with those of fifteen ot...

196 citations


Journal ArticleDOI
TL;DR: Observations support the premise that the superficial layers of non-goblet conjunctival epithelial cells can contribute to an increase in mucus production.
Abstract: • Biopsy specimens from the upper tarsal conjunctivae of ten patients with clinically evident contact-lens-associated giant papillary conjunctivitis (GPC) and eight asymptomatic contact lens wearers without clinically evident conjunctival changes were compared by light and transmission electron microscopy to determine the contribution of nongoblet epithelial cells to increased mucus. A control group consisted of five subjects who had never worn contact lenses. The apical cytoplasm of superficial nongoblet epithelial cells in specimens from all groups showed single-membrane-limited vesicular inclusions that stained metachromatically with toluidine blue and were positive with PAS staining, which indicated mucoprotein content. Some vesicles appeared to discharge their contents into the conjunctival sac. More vesicles were found in the GPC subjects and the asymptomatic contact lens wearers than in the normal subjects. These observations, coupled with the sign of increased or excessive mucus discharge in GPC subjects and in asymptomatic lens wearers, support the premise that the superficial layers of nongoblet conjunctival epithelial cells can contribute to an increase in mucus production.

73 citations


Journal ArticleDOI
TL;DR: The intracellular distribution of aminopeptidase-I in the intestinal and digestive cells of Mytilus edulishas has been shown to be the same as the lysosomal marker enzymes β-glucuronidase and N-acetyl-β-hexosaminidase, and the possible roles which these might play in intrACEllular osmoregulation in response to salinity change are discussed.
Abstract: The intracellular distribution of aminopeptidase-I in the intestinal and digestive cells of Mytilus edulishas been shown to be the same as the lysosomal marker enzymes β-glucuronidase and N-acetyl-β-hexosaminidase. Activity for these enzymes was also associated with the intestinal apical cytoplasm and microvillous border where there was pronounced staining for aminopeptidase-I. Experimental alterations of salinity induced changes in both microdensitometrically and spectrophotometrically determined aminopeptidase-I activity, as an increase with raised salinity and a decrease with lowered salinity. Lysosomal hexosaminidase showed similar changes in activity with altered salinity. Cytochemically determined lysosomal stability was also responsive to salinity changes, indicative of alterations in lysosomal functional capability. The lysosomal distribution of aminopeptidase-I is discussed in terms of the function of lysosomes in intracellular protein turnover, their high concentrations of free amino acids, and the possible roles which these might play in intracellular osmoregulation in response to salinity change.

68 citations


Journal ArticleDOI
TL;DR: Sodium maleate causes proteinuria due to a decreased tubular reabsorption of protein, and it demonstrates a decreased transport of protein from endocytic vacuoles to lysosomes in proximal tubule cells and a subsequent low tubular protein catabolism.

42 citations


Journal ArticleDOI
TL;DR: It is proposed that the pseudo-ductular lesions of the guinea pig pancreas are derived from acinar cells as a consequence of carcinogen induced cell proliferation leading to immature or dedifferentiated phenotypes.
Abstract: Tumors of the exocrine pancreas of the inbred strain 13 guinea pigs, induced by N-methyl-N-nitrosourea, reveal duct-like glandular differentiation and marked desmoplastic reaction of the stroma, characteristic of adenocarcinoma of human pancreas. During the course of induction of these tumors in the guinea pigs by N-methyl-N-nitrosourea, atypical pseudo-ductular proliferations were encountered in the pancreas which appeared to be precursor lesions for pancreatic carcinoma. The histogenesis of these pseudo-ductular lesions was studied by light and electron microscopy. The earliest changes consisted of dilatation of acinar lumina with decrease of apical cytoplasm and increased mitotic activity of the acinar cells. The actively proliferating, well-formed pseudo-ductules were lined by cuboidal or flattened epithelium containing a prominent nucleus and scant cytoplasm with few or no discernible zymogen granules by light microscopy. By electron microscopy, the cells lining the pseudo-ductules displayed features of immature or embryonic pancreatic acinar cells characterized by prominent nucleoli, marked decrease in rough endoplasmic reticulum with increase of free ribosomes, atypical zymogen granules and abundant microfilaments and microtubules. In two guinea pigs, transition from pseudo-ductular changes to adenocarcinoma was clearly evident. On the basis of these findings, it is proposed that the pseudo-ductular lesions of the guinea pig pancreas, and possibly those occuring in other species, are derived from acinar cells as a consequence of carcinogen induced cell proliferation leading to immature or dedifferentiated phenotypes. This hypothesis can, in part, be confirmed by immunocytochemical localization of pancreatic acinar cell specific secretory proteins and lectins in these pseudo-ductules.

34 citations


Journal ArticleDOI
TL;DR: The observations show that uterine epithelial cells can pinocytose substances derived from blood, transport them to the apical cytoplasm, and release them into the uterine lumen by exocytosis.
Abstract: By 20 min after intravenous injection of horseradish peroxidase on Day 5 of pregnancy the tracer was present between the lateral epithelial cell membranes, in coated and non-coated invaginations in the lateral and basal membranes of epithelial cells, and in pinocytotic vesicles at the periphery of epithelial cells By 60 min after injection the tracer was also distributed in vesicles throughout the epithelial cell cytoplasm By 2 h the tracer was present only in a few vesicles in the apical region of epithelial cells, and some of these vesicles appeared to be fusing with the apical cell membrane Pinocytotic invaginations in the basal membrane of uterine epithelial cells were 4--5-fold more numerous on Day 5 of pregnancy than on Days 1--4 and 7, suggesting a specific role for this activity during early pregnancy The observations show that uterine epithelial cells can pinocytose substances derived from blood, transport them to the apical cytoplasm, and release them into the uterine lumen by exocytosis

27 citations


Journal ArticleDOI
TL;DR: The cytodifferentiation of the intestinal Paneth cell was investigated in 2- to 50-day-old rats by evaluating the phenotypic expression of bacteriolytic lysozyme to provide further evidence that Paneth cells differentiate from a subpopulation of multipotent stem cells residing at crypt bases.
Abstract: The cytodifferentiation of the intestinal Paneth cell was investigated in 2- to 50-day-old rats by evaluating the phenotypic expression of bacteriolytic lysozyme. Samples of duodenum, jejunum, and ileum were exposed to anti-lysozyme antiserum and treated by the periodic-acid Schiff (PAS) technique for the demonstration of carbohydrate moieties. The distribution of the Paneth cell population was then assessed. At days 3-6, Paneth cells were present in ≤ 1% of intestinal crypts and exhibited (a) location in the bases of crypts, (b) apical granules positive for lysozyme, and (c) a slender truncated shape extending to the crypt lumen. By days 6-8, Paneth cells had acquired their typical broad, truncated shape and prominent secretory apparatus. Between 1 and 7 weeks postpartum, the frequency of Paneth cellcontaining crypts in duodenum rose from 9% to 79%; in jejunum and ileum the frequency increased through the third week of life and stabilized at 77%–93% thereafter. At all ages, a rostro-caudal gradient of crypts containing Paneth cells was observed, and greater numbers of paneth cells per crypt were seen caudally. In both suckling and weanling animals, two intermediate cell types were encountered. The first predominated at crypt bases through the fourth week of life and contained lysozyme-positive supranuclear granules, concomitant with an apical aggregation of PAS-positive material. The second type, identical to goblet cells in size and shape, predominated along the walls of intestinal crypts and at the bases of villi, and manifested both lysozyme-positive granules and PAS-positive mucigen droplets in the apical cytoplasm. This cell type appeared by day 12 and persisted through day 50. The results of this study provide further evidence that Paneth cells differentiate from a subpopulation of multipotent stem cells residing at crypt bases. The observation of Paneth cell-goblet cell transitional forms supports the view that these two cell types share a common lineage.

26 citations


Journal ArticleDOI
TL;DR: Iron in the tissues of the digestive tract of the common vampire bat has been studied using histochemical, electron microscopic, and autoradiographic methods to reflect the degree of siderosis of each animal's liver and spleen.
Abstract: Iron in the tissues of the digestive tract of the common vampire bat (Desmodus rotundus) has been studied using histochemical, electron microscopic, and autoradiographic methods. This animal is an obligate sanguivore and has a daily intake of dietary iron 800 times that of man. The amount and distribution of tissue iron is not affected by either a single blood meal or starvation but does reflect the degree of siderosis of each animal's liver and spleen. By 7 days after the injection of a trace amount of 55Fe into the peritoneal cavity, labelled siderotic macrophages are present both on the serosa and within the walls of the stomach and intestine. In the lower intestine, such cells can be derived from the germinal centers of Peyer's patches. Siderotic macrophages are often situated in the lamina propria under areas of siderotic epithelium. Label is also present in the apical cytoplasm of mucosal epithelial cells, a region of abundant siderosomes. The ultrastructure of these organelles is extremely variable. Accumulations of membranous whorls and stacks, "stippled bodies," ferritin molecules, and larger "ferruginous" complexes are bounded by one or a number of membranes. Iron is excreted when these epithelial cells are desquamated into the gut lumen. Similar Prussian blue-positive granules are present in the feces. Unlike other glandular cells, the parietal cells of the fundic caecum are siderotic. Their cytoplasm contains abundant siderosomes and ferritin with accumulations of amembranous ferritin bodies in the intracellular canalicular spaces. Prussian blue-positive granules are present in the lumens of fundic glands.

21 citations


Journal Article
01 Jan 1980-Cytobios
TL;DR: The data support the idea that Ca is sequestered in the golgi region, and transported within the secretory vacuoles to the plasma membrane for exocytosis to the lumen.
Abstract: Unfixed, freeze-dried and uncoated sections of lactating mammary tissue from rat were analysed for element concentration using a scanning electron microscope fitted with energy-dispersive X-ray analytical equipment. The subcellular concentration (mmol/kg dry weight) of calcium and several other elements (Na, Mg, P, S, Cl and K) was measured in: the basal-lateral cytoplasm, the nucleus, the apical cytoplasm, and the alveolar lumen in the lactating epithelium. The element concentration data was correlated to the ultrastructural features of the microprobed areas. Ca was concentrated, 4- to 5-fold, in the apical cytoplasm in comparison to other parts of the cell. The lumen contents show a 10-fold increase over the apical cytoplasm. The apical cytoplasm includes the Golgi apparatus and secretory vacuoles containing dense granules or casein micelles. The latter are numerous in the lumen. Because most of the CA in milk is known to be bound to the casein micelles, our data support the idea that Ca is sequestered in the golgi region, and transported within the secretory vacuoles to the plasma membrane for exocytosis to the lumen.

16 citations


Journal Article
TL;DR: It appears that protein secretion in the ram seminal vesicle follows the typical pattern of serous glands, and the possibility that fructose is extruded as the vacuoles open at the luminal cell surface is discussed.
Abstract: The ultrastructure of the secretory cells of the ram seminal vesicle was studied on material fixed by immersion or by vascular perfusion The signs of apocrine secretion seen after immersion fixation did not appear after perfusion fixation and are therefore interpreted as artefacts Instead, vacuoles with a granule in them were seen Such vacuoles were observed in the Golgi apparatus and in the apical cytoplasm Further indications of merocrine secretion were also found It therefore appears that protein secretion in the ram seminal vesicle follows the typical pattern of serous glands The possibility that fructose is extruded with the protein as the vacuoles open at the luminal cell surface is discussed

15 citations


Journal ArticleDOI
TL;DR: Myosin was localized in rat intestinal epithelium by means of indirect immunofluorescence and immunoelectron microscopy (unlabeled antibody peroxidase method), using a specific antibody to myosin from chicken gizzard.
Abstract: Myosin was localized in rat intestinal epithelium by means of indirect immunofluorescence and immunoelectron microscopy (unlabeled antibody peroxidase method), using a specific antibody to myosin from chicken gizzard. Immunoreactivity was localized in the apical cytoplasm, where it was concentrated along the rootlets of the microvillar filament bundles and in the terminal web. A model of microvillar contraction is proposed.

Journal ArticleDOI
TL;DR: The present results provide new morphological evidence for the vagus-nerve control of D cells, which may regulate the activity of islet cells.
Abstract: In an attempt to determine the neural control of pancreatic D cells, the pancreatic islets of the domestic fowl were examined electron microscopically from 1 to 28 days after abdominal vagotomy Exocytotic release of many secretory granules from D cells occurred one day after vagotomy Rough endoplasmic reticulum developed and formed an arrangement of concentric whorls in the cytoplasm of D cells after axotomy The altered D cells were also characterized by the occurrence of many peculiar dense bodies in the apical cytoplasm at all time periods studied These bodies varied in shape and size, containing several round vesicles The D cells were extensively depleted of granules after the longer time periods following vagotomy The present results provide new morphological evidence for the vagus-nerve control of D cells, which may regulate the activity of islet cells

Journal ArticleDOI
TL;DR: Epizootic diarrhea of infant mice (EDIM), studied under natural conditions, reveals a typical histopathological picture given by the vacuolation of the enterocytes of duodenojejunal villi, which often involves the entire length of the villi , sparing the crypts.

Journal ArticleDOI
TL;DR: Observations suggest the presence of an intracellular mechanism controlling the location and concentration of transported substrates during intestinal absorption.
Abstract: Electron-microscopy autoradiography, using freeze-dried frozen sections of unfixed tissue, was used to study the distribution of actively transported materials in the jejunal epithelium of the rat in vitro. After a few minutes incubation, the grain density over the organelle-packed interiors of the apical cytoplasm of the columnar absorptive cells was significantly greater than that over the structureless peripheral cytoplasm. This difference in the relative specific activities of the 2 subcellular compartments increased during accumulation of labelled galactose, and decreased as preloaded galactose was washed out of the epithelium. A similar compartmentation was observed in vascularly perfused intestines exposed to labelled galactose from either the mucosal or the serosal sides. These observations suggest the presence of an intracellular mechanism controlling the location and concentration of transported substrates during intestinal absorption.

Journal Article
TL;DR: Tansepithelial passage of protein was proven by its demonstration within the lysosomal systems of macrophages and nerves in the lamina propria and the demonstration of exogenous protein within the macrophage system of the colon is of interest in view of the putative allergic basis of certain bowel conditions.
Abstract: The uptake of exogenous protein by the colonic mucosa in neonatal rats was studied after enema infusions of horseradish peroxidase, of immunoglobulin conjugated with horseradish peroxidase, of unconjugated immunoglobulin, and of normal saline. Specimens of colonic mucosa were processed for the histochemical demonstration of peroxidase activity and then prepared for electron microscopy. Enzyme activity and, by inference, exogenous protein were located on the luminal plasma membrane of epithelial lining cells, in pinocytotic vesicles in their apical cytoplasm, in Golgi-associated sacs and in their secondary lysosomes. Protein was also located within lymphocytes which had invaded the epithelium. Transepithelial passage of protein was proven by its demonstration within the lysosomal systems of macrophages and nerves in the lamina propria. The demonstration of exogenous protein within the macrophage system of the colon is of interest in view of the putative allergic basis of certain bowel conditions.

Journal Article
TL;DR: Changes in oviductal lesions associated with the continuous feeding of diethylstilbestrol seem to indicate continued protein synthesis by the secretory cells but a deficiency in the packaging of this protein into secretory granules.
Abstract: Selected oviductal lesions associated with the continuous feeding of diethylstilbestrol (DES) were examined ultrastructurally Virgin female mice were fed diets containing 0, 320 and 640 ppb DES from 4 weeks of age. All animals reported on in this study were removed from the study and sacrificed for histopathological and electron microscopy examination when moribund and ranged from 622 to 762 days on the experiment. One oviductal change consisted of markedly vacuolated ciliated epithelial cells located primarily in the fimbria. Electron microscopy revealed that the large vacuoles were present throughout the cytoplasm of affected cells. These vacuoles were not lipid and appeared to be fluid-filled. No significant alterations in number or structure of cilia were observed. Since this alteration was seen in both DES and control animals, it may be age-related. A second kind of oviductal lesion consisted by enlarged secretory cells located predominantly in the isthmus. The cytoplasm of these cells consisted of extremely enlarged, dilated rough endoplasmic cisternae forming a subnuclear mass. Numerous primary and secondary lysosomes were seen in the apical cytoplasm between the cell membrane and nucleus. No evidence of a Golgi complex was seen. These alterations were seen only in DES-exposed animals and seem to indicate continued protein synthesis by the secretory cells but a deficiency in the packaging of this protein into secretory granules.