Showing papers on "Apical cytoplasm published in 1971"

Epididymal physiology. II. Immunofluorescent analyses of epithelial secretion and absorption, and of bovine sperm maturation.

Abstract: The antigenic changes in bull spermatozoa during maturation and senescence were studied. An attempt was made to localize areas of antigen secretion and absorption within the epididymis and vas deferens using sperm immunofluorescence. acrosomal immunofluorescence of sperm portions was not observed except in presumably senscent spermatozoa from spermatocoeles. Nonciliated antigen-secreting cells were detected by their immunofluorescence in the epithelium of the efferent ducts within the proximal caput epididymidis. These secretory cells produce sperm-coating proteins which are antigenically similar to certain components of seminal vesicle fluid. Immunofluorescence of the apical cytoplasm and stereocilia in the proximal caput epididymidis indicated that this epithelium probably absorbed sperm-specific proteins emanating from the testis. Immunofluorescence in the apical cytoplasm of the epithelium lining the corpus and proximal cauda epididymidis was suggestive of secretory activity. Similar fluorescence in the epithelium of the vas deferens may have resulted from absorption of proteins.(Authors modified)

Ultrastructural studies of the secretion of calcium carbonate by the serpulid polychaete worm, Pomatoceros caeruleus.

Abstract: Pomatoceros caeruleus possesses a pair of simple acinar calcium-secreting glands lying in the ventral peristomium. Each gland has a single large secretory acinus containing columnar secretory cells with basal nuclei. Golgi complexes and flattened cisternae of the rough endoplasmic reticulum are abundant in the midregion and secretory vacuoles fill the apical cytoplasm. Elongate microvilli extend from the apices of the cells into the gland lumen. An organelle-free zone, the intracellular channel, extends from near the base almost to the apex of the cells. It is bordered on one side by the lateral cell membranes and is separated from the organelle compartment by elongate profiles of the rough endoplasmic reticulum. The secretory products of the calcium-secreting glands have the form of cubic or rhombohedral granules with average dimensions of 150–200 mμ on a side. The granules are composed of a fibrous organic matrix in which needle-like calcite crystals are deposited. The possible mode of synthesis of the calcified secretory granules is discussed.

Attachment reaction of rat uterine luminal epithelium. II. The effect of progesterone on the morphology of the uterine glands and the luminal epithelium of the spayed, virgin rat.

Abstract: Ovariosalpingectomized rat uterine glands and luminal epithelium were examined by electron microscopy and in serial cross sections under light microscopy after up to 8 days of treatment with 5 mg progesterone daily. Under light microscopy the gland lumen was narrow or absent in many epon sections but wide in many paraffin sections filled with toluidine blue stained secretion and serial sections showed that the openings were closed allowing no connection between the gland lumen and the uterus. In electron micrographs only those glands without an opening appeared altered by progesterone. The most notable differences in the glandular epithelium were microvilli condensed ribosome-free cytoplasm next to the lumen numerous vesicles sacs and dilated Golgi cisternae in the apical cytoplasm and more giant mitrochondria in the basal cytoplasm than usually seen in controls. In the luminal epithelium there were 3 distinct regions: the apical region had condensed cytoplasm often extruded into the lumen with close-packed smooth empty vesicles; the middle region had granular endoplasmic reticulum mitrochondria dense bodies multivesicular bodies and lipid granules; the basal region contained the nucleus granular endoplasmic reticulum mitrochondria and dense abodies. These observations were interpreted as indicative of a transitional state from secretion to absorption especially since without an opening secretion would be of little significance.

Brunner's glands of the duckbilled platypus (Ornithorhynchus anatinus).

Abstract: Brunner's glands in the platypus form a lobulated, glandular collar confined to the submucosa of the most distal portion of the stomach. The glands end immediately proximal to the gastrointestinal junction and excretory ducts empty in the region where the stratified squamous epithelium lining the stomach changes abruptly to the intestinal lining epithelium of the duodenum. An individual gland of Brunner is composed of several elongate lobules drained by intralobular ducts which often join to form a single excretory duct. Light and electron microscopic studies have shown the secretory tubules to be comprised of large, pyramidal cells limited basally by a delicate basal lamina. The ergastoplasm, cisternae of which are dilated and contain amorphous material, is associated with numerous ribosomes. In basal and perinuclear regions intercisternal granules and smooth surfaced vesicles are found. Numerous small vesicles found in supranuclear areas apparently form from the smooth membrane portions of ergastoplasm located adjacent to Golgi complexes. Membrane-bound amorphous granules of varying electron density occupy the apical cytoplasm and show a tendency to coalesce before emptying their contents into the adjacent lumen. The intralobular duct system is lined initially by a columnar epithelium which changes to a simple squamous form before the ducts combine to form a short excretory duct lined by stratified squamous epithelium. The epithelium lining the duct system contains relatively few organelles but appears to be engaged in a limited amount of synthesis and release of secretory material. Histochemical studies indicate that both the secretory tubules and the duct system elaborate a neutral mucopolysaccharide.

Ultrastructural differentiation of the endodermal cells of the yolk sac of the bat, Tadarida brasiliensis cynocephala.

Abstract: In Tadarida, the endodermal cells that form the yolk sac originally delaminate from the inner cell mass and proliferate to form a complete lining of the trophoblastic vesicle, creating a bilaminar omphalopleure. These cells remain squamous until the splanchnic mesoderm migrates in between the two layers of the omphalopleure, at which time they begin to hypertrophy. The current study is an analysis of the cytological changes that accompany this hypertrophy as well as additional changes that occur throughout the remainder of the gestation period. Among the early changes are: (1) the formation of numerous microvilli along the apical surface of the cells, (2) the appearance of coated vesicles, also along the apical plasma membrane, (3) the establishment of a system of absorption tubules in the apical cytoplasm, (4) an increase in mitochondria, and (5) the appearance of glycogen within the channels of the membranous organelle. A wave of hematopoietic activity follows the migration of splanchnic mesoderm around the trophoblastic vesicle, and at this time the erythroblasts and embryonic erythrocytes can be seen in a close relationship with the endodermal cells. Subsequent changes include the enlargement of the membranous organelle and the appearance of a paracrystalline membranous structure. In addition, the endodermal cells store large quantities of lipid and glycogen that are substantially depleted just before birth.

An electron microscopic study of the small intestine in human cholera.

Abstract: An electron microscopic study of the small intestine in human cholera has shown severe interstitial edema in the lamina propria due to an increased vascular permeability with rarefaction of the endothelial cells (source of water). The epithelial intercellular spaces basal to the apical junctional complex is irregularly widened (intercellular passage of water).

Ultrastructure of calcium phosphate-containing cells in the serpulid polychaete worm Pomatoceros caeruleus.

Abstract: A small patch of cells in the epithelium of the anterior surface of the collar of the serpulidPomatoceros caeruleus contains membrane-bound vacuoles filled with crystalline material. The crystals have rhomboidal or rectangular profiles and have been shown by electron diffraction analysis to be composed of hydroxyapatite and calcium magnesium phosphate. The apices of the cells are bordered by microvilli. Some cells also have apical cilia. The cells contain Golgi complexes in the apical cytoplasm. Large numbers of mitochondria are distributed thoughout the cytoplasm. The possible function of these mineral-containing cells as sites for storage of calcium and/or phosphorus is discussed.

Some observations on the fine structure of thyroids of hibernating and aroused bats

Abstract: The fine structure of thyroids of hibernating and aroused bats, Myotis lucifugus, was observed with the electron microscope. (1) In the hibernating bat for 5 months the thyroid follicular epithelial cell is markedly attenuated and the rough endoplasmic reticulum and Golgi apparatus are very poor in development, while the mitochondria are larger and distributed throughout the cytoplasma. Intracellular colloid droplets are difficult to find. Homogeneously dense small granules suggesting primary lysosomes are numerous. Half an hour to 2 hours after injection of 100 μc of 125I, very few silver grains are recognized in a follicle lumen electron microscopic autoradiographically. (2) Half an hour to 2 hours after the intraperitoneal injection of 1 unit of thyroid stimulating hormone (TSH) into hibernating bats, several colloid droplets, many small smooth-surfaced vesicles and a few coated vesicles appear in the apical cytoplasm of the thyroid follicle epithelial cell. The small vesicles are gathered around the large droplet, and some of them are fused with it. The rough endoplasmic reticulum does not show any marked reaction. These facts suggest the possibility that the luminal colloid is reabsorbed in the form of large droplets as well as in the form of small vesicles. Dense granules (lysosomes) gathered near the colloid droplets and some of the colloid droplets themselves become heterogeneously dense. Half an hour to 2 hours after injection of 100 μc of 125I simultaneously with TSH into hibernating bats, silver grains which are markedly increased in number, as compared with those of the non-treated hibernating animal, are recognized in the follicle lumen electron microscopic autoradiographically. (3) At 2–3 hours after injection of TSH into the hibernating bat, the appearance of crystals in over half of the colloid droplets is characteristic. Each crystal consists of aggregates of numerous needle-like filaments, about 65 A in diameter, running parallel with one another. Center to center distances between these filaments cut in longitudinal section are about 150 A. The filaments are arranged regularly along two or three axes. These crystals are considered to be altered thyroglobulin. (4) The follicular epithelial cells of aroused bats (24° C, laboratory room in winter) from the hibernation show heterogeneity in their fine structure. Some cells seem active, and the others look inactive. In 15-day aroused bats, though most cells are flattened and the rough endoplasmic reticulum is sparse, a few cells show a fairly well developed rough endoplasmic reticulum with somewhat dilated cisternae. Large colloid droplets occur sometimes in a few cells. Lysosomal dense granules, reduced in number as compared with those of hibernating animals, are considered to originate from the Golgi apparatus. In 30 and 40-day aroused bats, the rough endoplasmic reticulum of most cells becomes more enlarged, and some follicular cells are quite similar to those of non-hibernating bats obtained in the field. In 60-day aroused bats, all the follicular epithelial cells show quite the same feature as the active thyroid cell of non-hibernating mammals.

Changes in the ultrastructure of Nematospiroides dubius (nematoda) intestinal cells during development from fourth stage to adult.

Abstract: The general fine structure of intestinal cells and changes which occur in ultrastructure during development from fourth-stage to adult N. dubius are reported. In fourth-stage worms pigment granules are prominent in intestinal cells. In adults the number of pigment granules appears to be reduced and phagolysosomes containing membranous profiles and pigment material increase in number. Another reorganization of cell structure involves mitochondria which are randomly distributed in the cytoplasm of cells in fourth-stage worms, concentrated in the apical cytoplasm in worms in the molting process, and confined to the base of cells in adult worms. Other changes involved structure of the nucleus, rough endoplasmic reticulum and glycogen content of cells.

Localization of parotin in bovine parotid gland, demonstrated by the immunohisto-chemical method

Abstract: The localization of parotin, which has been believed to have hormonal properties, is demonstrated in bovine parotid gland by means of immuno-histochemical technique.The bright specific fluorescence, showing the localization of parotin, was encountered in the cytoplasm of supra- and para-nuclear regions in the cells of the duct system, but was not seen in the myoepithelial cells situated at the basal part of the duct. While, there was no specific fluorescence in the cytoplasm of the acinar cells. This fact explained that the presence of parotin was not able to be proved in the cytoplasm of the acinar cells by the immuno-histochemical method. On the other hand, according to the Ogata's report (1939), the parotin produced in the acinar cells was secreted into the lumen of the acinus, and the major part of the secreted parotin was re-absorbed in the apical cytoplasm of the cells of the striated duct. The absorbed parotin was then supposed to remove toward the basal part of the cells and to be oozed out into the interstitial connective tissue. If parotin were taken into the lumen of the lymphatic or blood vessels in such a way as mentioned above, strong specific fluorescence would not be observed at all in the intercalated duct or in the excretory duct. Consequently, parotin may be produced by the duct cells, or little amount of the parotin secreted from the acinus may be condensed in the tubular portion, or the presumable precursor of parotin may be secreted by the acinar cells and transformed into the parotin as soon as the precursor is re-absorbed in the duct cells.