Showing papers on "Apical cytoplasm published in 1976"

Effect of thiol-oxidation of glutathione with diamide on corneal endothelial function, junctional complexes, and microfilaments.

Abstract: Intracellular-reduced glutathione (GSH) was removed by thiol-oxidation with diamide during in vitro perfusion of the corneal endothelium. By 15 min the normal mosaic-like pattern of the endothelial cells was disrupted by serpentine-like lines of cell separation at the cell juntions. After 45 min of perfusion, infividual clusters of cells formed cup-shaped islands. The resultant exposure of Descemet's membrane to the perfusion solution resulted in corneal swelling. Transmission electron microscopy revealed that the endothelial cells separated at the apical junctions and that the microfilaments in the apical cytoplasm of cells formed dense bands, whereas the other subcellular organelles were normal in appearance. The change in cellular shape may be due to loss of cellular adhesion which results in the condensation of the microfilaments or contraction of the microfilaments. The addition of glucose to the perfusate prevented the diamide effect, and the diamide effect could be reversed upon removal and perfusion of a glutathione bicarbonate Ringer's solution. These results suggest that the ratio of reduced to oxidized glutathione in the endothelial cells plays a role in the maintenance of the endothelial cell barrier function.

Uteroglobin in the rabbit. I. Intracellular localization in the oviduct, uterus, and preimplantation blastocyst.

Abstract: The localization and release of uteroglobin (UGL) were investigated immunohistologically in the oviducts and uteri of female rabbits from oestrus through the 7th day post coitum and the blastocyst on the 7th day post coitum. UGL was detected within Fallopian tube cells even during oestrus. Granules of UGL appeared toward the bases of these cells. Subsequently, the cells became almost entirely filled with UGL. Drop-like protrusions of the apical cytoplasm suggest a mechanism of apocrine extrusion. All stages of filling and extrusion were visible during the entire preimplantation period. During oestrus, synthesis of UGL within uterine cells becomes sufficiently advanced so that extrusion has either already begun or is about to begin. UGL positive material first appears in the supranuclear regions. Later the entire cytoplasm shows a positive reaction. An uneven distribution of UGL cells is observed in the endometrium. Since only the glands adjacent to the myometrium and cells of the cavum epithelium contain UGL, a striking mosaic of UGL positive and negative cells results. The present report is the first detecting UGL in single cells of the blastocyst. Both entodermal and ectodermal cells proved to be UGL positive. The synthesis and section of UGL in the oviduct and uterus and the possible origins of UGL in the blastocyst are discussed.

Fine structure and cytochemistry of the intralobular ducts of the human parotid gland

Abstract: An intralobular duct of a human parotid gland has two parts, an intercalated part and a striated part. Intercalated ducts are lined with low cuboidal cells endowed with scanty cytoplasmic organelles. Striated ducts are lined with columnar cells rich in mitochondria and glycogen particles, and are characterized by extensive infoldings of the basal plasma membrane. The apical cytoplasm of the cells of the striated ducts shows a number of membrane-bound granules having a diameter of about 0-15 mum. These granules contain material of varying electron density which does not react with silver or with the histochemical reagents employed in the present study. Thus, on the basis of their small size and histochemical characteristics, they are distinct from the large and dense secretory granules observed in the so-called granular striated ducts of some animals. In addition, cells of striated ducts contain lysosomes, peroxisomes, and large lipoid bodies which give histochemical reactions typical of lipofuscins. Bodies of myoepithelial cells have been observed only in intercalated ducts. Their processes, however, extend into the proximal parts of striated ducts.

Ultrastructure of baboon parotid gland

Abstract: The parotid gland of the olive baboon, Papio anubis, was examined by electron microscopy. The acini are all serous in nature, and consist of pyramidal cells with abundant secretory granules of varying size. These granules consist of a dense matrix in which a denser spherule or lenticular body is present. Granules linked by a short isthmus are observed in the apical cytoplasm, and granules in the process of discharging their contents to the acinar lumen may be connected to the luminal plasma membrane by a neck-like protrusion. Intercalated duct cells contain granules reminiscent of those found in the rat submandibular acinar cells. The striated ducts consist of tall cells interlocked in a complex fashion near their bases, with numerous vertically-oriented mitochondria lodged in their basal crenulations. Small vesicles whose contents vary in density are present in the apical cytoplasm as are large deposits of lipofuscin. The striated duct cells display a proclivity for ballooning into the duct lumen. Excretory ducts consist of simple to pseudostratified columnar epithelium, and lack basal striations or apical blebs.

Studies on the posterior silk gland of the silkworm Bombyx mori. VI. Distribution of microtubules in the posterior silk gland cells.

Abstract: There are two microtubule systems in the posterior silk gland cells. One is a radial microtubule system in which the microtubules run radially from the basal to the apical cytoplasm and in which fibroin globules (secretory granules of fibroin) and mitochondria are arranged along these microtubules, thus composing a "canal system" which is assumed to be responsible for the intracellular transport of fibroin globules. The other is a circular microtubule system in the apical cytoplasm which is composed of bundles of microtubules and microfilaments running in a circular arrangement around the glandular lumen at an interval of approximately 4 mum at the end of the fifth instar. This system is presumably concerned with secretion and/or intraluminal transport of fibroin.

Electron microscope immunohistochemical localization of thyroglobulin in the rat thyroid gland.

Abstract: In order to make a precise identification of the organelles containing thyroglobulin (TG) in the thyroid follicular cells, an electron microscope immunohistochemical localization of TG was conducted in the rat thyroid gland. In both control and TSH-treated rats, TG was detected in the follicular lumen, in large vesicles which correspond to the classical colloid droplets, in apical vesicles, and also in the apical cytoplasm. When the formation of colloid droplets was prevented by the previous administration of L-thyroxine, a positive reaction for TG was observed only in the colloid and apical vesicles, and diffusely in the cytoplasm. These results clearly establish for the first time the presence of immunoreactive TG in apical vesicles, luminal colloid and colloid droplets, and cytoplasm (possibly cell sap). They confirm previous indirect evidence suggesting that apical vesicles are involved in the transport of TG and that colloid droplets whose formation is induced by TSH, do contain TG. (Endocrinology 98...

Freeze-etching observations on the characteristic arrangement of intramembranous particles in the apical plasma membrane of the thyroid follicular cell in TSH-treated mice

Abstract: Thyroid glands of normal, TSH-treated and Thyradin (powdered thyroid)-treated mice were examined by means of the freeze-etching method. Intramembranous particles on the PF (= A face) face of the apical plasma membrane often form aggregates especially in TSH-treated mice. Each aggregate, about 200 nm in diameter, and consisting of 15–25 large particles, corresponds to a depression of the apical cytoplasm, and the particles sometimes form rosettes. Particle-aggregates are very rare in the apical plasma membrane of the thyroid follicular cell of the Thyradin-treated animal. In the cytoplasm just beneath the particle-aggregate no secretory granules, reabsorbed colloid droplets or other special structures are found.

Some histochemical studies on the prostate, urethral and bulbourethral glands of the one-humped camel (Camelus dromedarius).

Abstract: The histochemical localization of carbohydrates, ribonucleoproteins (RNA), lipids, some hydrolytic enzymes, succinate and lactate dehydrogenase and acetylcholinesterase were investigated in the prostate, urethral and bulbourethral glands of the camel. These glands probably secrete carbohydrate-protein complexes. In the bulbourethral glands, they are sulphated mucopolysaccharides. RNA was seen in the cytoplasm of the prostate and urethral glands. Neutral lipids were cytoplasmic and present in moderate amounts in the prostate and urethral glands and in traces, in the bulbourethral gland. Acid phosphatase-containing granules were abundant in the prostate, moderate in the urethral glands and in traces in the bulbourethral glands. Alkaline phosphatase was observed in the apical cytoplasm of the prostate and bulbourethral glands and in the ducts of the urethral glands. ATPase and adenosine 5-monophosphatase were seen in the basal laminae and interstitial tissue. In the urethral glands, adenosine 5-monophosphatase was distributed diffusely in the cytoplasm. Succinate dehydrogenase was seen in the urethral and bulbourethral glands. Varying degrees of lactate dehydrogenase activity was observed in all the glands. Acetylcholinesterase was confined to neural elements. The pars disseminata and the urethral glands were considered as two distinct glandular zones along the pelvic urethra. The significance of these histochemical results is discussed.

Cyclic ultrastructural changes in ewe uterine tube (oviduct) infundibular epithelium.

Abstract: Ultrastructural features of the uterine tube (oviduct) infundibulum of ewes have been studied, with special reference to cyclic changes in the ciliated and the secretory cells. Tissue from the uterine tube infundibulum was taken from 12 Rambouillet crossbreed ewes which were killed at intervals (days 1 (or estrus), 3, 9, 10, 12, and 16) throughout the estrous cycle. The presence of cilia was demonstrated throughout the estrous cycle, and true degeneration or loss of cilia was not apparent at any phase of the cycle. Presence of fibrous granules, which are supposedly related to basal body replication, was demonstrated in the apical cytoplasm of ciliated cells on day 1 of the estrous cycle. Small ciliary buds were especially present on day 1, indicating active formation of cilia during the follicular phase of the cycle. The presence of fibrous granules, basal bodies, and ciliary buds at estrus indicates that ciliogenesis in the ewe uterine tube is stimulated by high levels of endogenous estrogen. Rootlets were observed both during the follicular and the luteal phases of the cycle. The rootlets were about 1 mum long, and their fine structure indicates that they might function as anchoring structures for the motile cilia. The most striking feature during estrus was the occurrence of glycogen granules in the cytoplasm of ciliated and secretory cells. These granules were in the apical cytoplasm and basal region of some epithelial cells. They were minimal or absent during the luteal phase of the estrous cycle. The presence of electron-dense glycogen particles was clearly demonstrated within basal bodies. Possibly the glycogen within the basal bodies functions as a source of energy for ciliary movement and the cytoplasmic glycogen as nourishment for the ovum. The secretory cells also showed characteristic cytologic changes which were correlated with the phase of the estrous cycle. Maximal secretory cell differentiation was apparent during the follicular phase, at which time these cells were characterized by well-developed rough endoplasmic reticulum, numerous ribosomes, and secretory granules of varied size, shape, and density. A most remarkable feature of the granules was their membranous structure, consisting of concentric lamellae of equal dimensions. Typical extrusion of secretory granules into the tubal lumen was apparent during the follicular and the luteal phases of the estrous cycle. Cytoplasmic projections containing nuclei protruded into the tubal lumen and some were free in the lumen, especially during the luteal phase of the estrous cycle. The presence of a well-developed endoplasmic reticulum and numerous secretory granules during estrus indicate that secretion in the ewe uterine tube is presumably under the control of circulating high plasma concentrations of estrogen.

Electron microscopic studies of estrogen-induced ciliogenesis and secretion in uterine tube of the gilt.

Abstract: The time required for occurrence of estrogen-induced uterine tubal (oviductal) ciliogenesis and for differentiation of secretory cells was studied, utilizing electron microscopy procedures. Sixteen cycling gilts were ovariectomized; 3 to 4 months later, 12 principal gilts were each given subcutaneous injections of 17 beta-estradiol in 0.5 ml of corn oil at the rate of 200 mug/day, and 4 control gilts were given injections of corn oil only at the rate of 0.5 ml/day. Two principals each were killed on days 1, 2, 3, 4, 5, and 7 after start of treatment. The epithelial heights were low and completely atrophied 3 to 4 months after ovariectomy. Uterine tubal cilia were absent in all the control gilts. Cytologic changes were not seen in the atrophied epithelium of ovariectomized gilts 1 day after estradiol treatment, but definite proliferative elements consisting of an extensive fibrillar meshwork encrusted with granules (60 to 80 nm) were observed in close association with the nuclear envelope and in the apical cytoplasm after 2 days of estradiol treatment. By day 3, enlarged electron-opaque granules referred to as condensation forms, undergoing various stages of depletion, were closely associated with radially arranged procentrioles. These associations have been referred to as generative complexes. The presence of many generative complexes indicates that maximal production of basal bodies can be expected after 3 days of treatment with estradiol. The depletion of the condensation forms produced hollow spheres with thin walls as the procentrioles grew in length and assembled their microtubules. Enlarged mature-appearing basal bodies were abundant in the cytoplasm after 3 days of estradiol treatment. These bodies aligned themselves linearly along the luminal surface of the cell. Small ciliary buds were then formed above the cell surface, and ciliary filamentogenesis occurred in the bud. Motile cilia were observed on day 3, but cilia numbers increased markedly between day 4 and days 5 and 7. Procentrioles were generated from the diplosomal centriole after 2 days of estradiol treatment. These observations have provided evidence for both ancentriolar and centriolar basal body replication in the ciliated cells of uterine tube of the gilt. Maximal secretory cell differentiation occurred after 3 days of estradiol treatment. Hypertrophy of cytoplasmic organelles was evident on day 3, but the number of secretory granules and amount of rough endoplasmic reticulum increased markedly on days 5 and 7. Close association of secretory granules, Golgi apparatus, and endoplasmic reticulum was evident after estadiol treatment. These data indicate that both ciliated and secretory cells are sensitive to estrogen.

A quantitative study of pinocytosis and lysosome function in experimentally induced lysosomal storage.

Abstract: The highly pinocytic epithelial cells of the visceral yolk sac from 17.5-day rat conceptuses were used as a model in which to induce engorgement of the vacuolar system by direct accumulation of substances that are not hydrolysed by lysosomal enzymes. The ultra-structural appearances of these cells in pregnant animals that 24-48h before had received intraperitoneal injections of Triton WR-1339, polyvinylpyrrolidone, dextran or sucrose revealed gross abnormalities that were confined to the vacuolar system; in comparison with normal tissue the number, and in some cases the size, of vacuoles was increased, leading to close packing within the apical cytoplasm and distortion of the normal rounded shape. By culturing yolk sacs in vitro, rates of ingestion of 125I-labelled polyvinylpyrrolidone and of 125I-labelled bovine serum albumin were determined, together with the rate of digestion of the labelled protein. The rates of exocytosis of 125I-labelled polyvinylpyrrolidone and of lysosomal enzymes were also determined. No significant differences between normal and highly vacuolated tissues were found. Apparently marked vacuolation of these cells by these agents is without significant effect on pinocytosis, exocytosis or intralysosomal proteolysis.

The effect of carbofuran-toxication on the chloragogen tissue of Tubifex tubifex Müll. (Oligochaeta).

Abstract: Chloragogen cells, subserving ion exchange and electron accepting functions, were studied in Tubifex tubifex after insecticide treatment. Chloragogen cells were strongly influenced by in vivo carbofuran poisoning. The first alterations in the chloragogen cells became activated, both the formation and release of the chloragosomes reached a high rate. The released chloragosomes were phagocytosed by the amoebocytes. At an advanced stage of the toxication a heavy loading of the apical cytoplasm of chloragogen cells with lipid droplets, finally degenerative changes both in the chloragogen cells and amoebocytes were observed. Possible mechanisms of the carbofuran toxication and of the protective function of chloragogen cells in T. tubifex are discussed.

Ultrastructural studies of prepubertal porcine uterine tube epithelium.

Abstract: Ultrastructural details of prepubertal porcine uterine tube (oviduct) were studied in normal, growing gilts and compared with observations reported in other species. Tissues from the ampulla region of uterine tube were taken from 6 prepubertal gilts (106 to 139 days old) to determine cytodifferentiation of ciliated and secretory cells. The epithelium consisted of 2 distinctive cells, the ciliated and the secretory cells. Cilia were observed in the uterine tube of prepubertal gilts; however, degeneration of cilia was not observed in the present study. Most prominent observations were the occurrence of fibrous granules in the apical cytoplasm of ciliated cells. These fibrous granules contained electron-dense material and were present near basal bodies. The most unusual feature was the occurrence of procentrioles around a condensation form. These data indicate that ciliated cells are sensitive to estrogen. Intimate morphologic association between fibrous granules and basal bodies indicate that fibrous granules might provide precursor material for the development of cilia and rootlets. The cytoplasm of the secretory cells contained rough endoplasmic reticulum of tubular form and numerous ribosomes. Evidence for synthesis, storage, and release of secretory granules was not apparent. It is suggested that the secretory cells are not sensitive to the low, circulating concentration of plasma estrogen. The ultrastructure of the stromal cells and lymphatic capillary was described for the 1st time. The uterine tube stromal cells were characterized by prominent nucleus and a few cytoplasmic organelles. The lymphatic capillaries were distinguished by the blood capillaries, their much wider lumen, endothelium with an attenuated cytoplasm, absence of basal lamina, and overlapping and interdigitating intercellular junctions. The fine structure of the porcine uterine tube lymphatic capillary generally resembled that of other mammalian species.

Electron microscope study on the tracheal epithelium of rats with special references to the non-ciliated cells

Abstract: To elucidate the ultrastructural organization of the tracheal epithelium and especially the fine structure of the non-ciliated cells (brush cells), the electron microscope observations were carried out. Many rats in the postnatal developmental stages and adult ones were used in this study. The tracheal epithelium of the rats is composed of a simple columnar or a pseudostratified ciliated epithelium, and it contains four distinct types of cells; ciliated cells, mucous cells (goblet cells), basal cells, and non-ciliated cells (brush cells). The ciliated cell has a clear cytoplasm compared with those of the other types of cells and favorable amount of cell organelles. Sometimes, the process of the ciliogenesis can be sproradically seen in the presumably ciliated cells early in the postnatal developmental stages and also in the adult ones. The mucous secretory cells with a fairly dense cytoplasm provided with plenty of rER and other cell organelles are more predominant in number in immature rats. However, there are scarcely seen the mucous cells provided with a typical goblet composed of many secretory granules in the apical cytoplasm. Non-ciliated cells aligned the luminal surface of the tracheal epithelium are divided into two categories, one is the mucous secretory cell and the other is the so-called brush cell provided with the brush border on its luminal surface, and the latter also contains many characteristic granules of small size. Some of these granules contain a dense spherical core, and frequently situate in the basal part or along the lateral cell boundary clustered in small groups. On the other hand, there are frequently observed many naked nerve endings, and most of them contain both small clear vesicles and large cored vesicles, and others contain also small granular vesicles, neurotubules, small mitochondria or scarce glycogen particles. However, no epithelioneural junctions can be discerned between the brush cells and the nerve endings in the epithelium. These findings mentioned above may be probably assumed that the brush cell plays a role of an endocrine function to secret the containing granules into the connective tissue of the tracheal mucous membrance in rats.

VI. Distribution of Microtubules in the Posterior

Abstract: There are two microtubule systems in the posterior silk gland cells. One is a radial microtubule system in which the microtubules run radially from the basal to the apical cytoplasm and in which fibroin globules (secretory granules of fibroin) and mitochondria are arranged along these microtubules, thus composing a "canal system" which is assumed to be responsible for the intracellular transport of fibroin globules. The other is a circular microtubule system in the apical cytoplasm which is composed of bundles of microtubules and microfilaments running in a circular arrangement around the glandular lumen at an interval of -4/zm at the end of the fifth instar. This system is presumably concerned with secretion and/or intraluminal transport of fibroin. It has been suggested by a number of authors that microtubules are involved in the secretion processes of a variety of cells such as the secretion of