scholarly journals INFOLDED BASAL PLASMA MEMBRANES FOUND IN EPITHELIA NOTED FOR THEIR WATER TRANSPORT

1956 ◽  
Vol 2 (4) ◽  
pp. 203-208 ◽  
Author(s):  
Daniel C. Pease
Keyword(s):  
Choroid Plexus ◽  
Water Transport ◽  
Ciliary Body ◽  
Plasma Membranes ◽  
Cell Layer ◽  
Submaxillary Gland ◽  
Basal Surface ◽  
Basal Plasma ◽  
Marked Tendency ◽  
Secretory Ducts

Epithelia noted for their water transport have been studied by electron microscopy with particular emphasis upon basal specializations. Epithelia of the submaxillary gland, choroid plexus, and ciliary body are described in this article, and compared with previous observations on the kidney. The basal surface of all these epithelia is tremendously expanded by folds which penetrate deeply into the cytoplasm. In the submaxillary gland this is particularly notable in cells of the serous alveoli and in the secretory ducts. In these instances the folds have a fairly regular distribution and have a marked tendency to turn back upon themselves and so form repeating S-shaped patterns. In the choroid plexus the penetrating basal folds are limited to the lateral regions of each ependymal cell where they blend with the intercellular membranes that are also folded. In the epithelium of the ciliary body it is the inner layer that is specialized. The surface adjacent to the cavity of the eye penetrates irregularly, nearly through the full depth of the cell layer. The exposed surface is, in a fundamental sense, the basal surface of this epithelial layer. It is apparent that the pattern of folding is quite distinctive in the different epithelia. Therefore, the specializations should be regarded as analogous rather than homologous. Topographic considerations presumably limit the manner in which basal cell surfaces might be expanded. Penetrating folds would seem to represent almost the only possible solution.

scholarly journals Insulin Stimulates GLUT4 Trafficking to the Syncytiotrophoblast Basal Plasma Membrane in the Human Placenta

2019 ◽  
Vol 104 (9) ◽  
pp. 4225-4238 ◽  
Author(s):  
Laura B James-Allan ◽  
Jaron Arbet ◽  
Stephanie B Teal ◽  
Theresa L Powell ◽  
Thomas Jansson
Keyword(s):  
Plasma Membrane ◽  
Protein Expression ◽  
Membrane Trafficking ◽  
Human Placenta ◽  
Plasma Membranes ◽  
Glucose Transporter ◽  
Maternal Obesity ◽  
Normal Body Mass Index ◽  
Basal Plasma Membrane ◽  
Basal Plasma

AbstractContextPlacental transport capacity influences fetal glucose supply. The syncytiotrophoblast is the transporting epithelium in the human placenta, expressing glucose transporters (GLUTs) and insulin receptors (IRs) in its maternal-facing microvillous plasma membrane (MVM) and fetal-facing basal plasma membrane (BM).ObjectiveThe objectives of this study were to (i) determine the expression of the insulin-sensitive GLUT4 glucose transporter and IR in the syncytiotrophoblast plasma membranes across gestation in normal pregnancy and in pregnancies complicated by maternal obesity, and (ii) assess the effect of insulin on GLUT4 plasma membrane trafficking in human placental explants.Design, Setting, and ParticipantsPlacental tissue was collected across gestation from women with normal body mass index (BMI) and mothers with obesity with appropriate for gestational age and macrosomic infants. MVM and BM were isolated.Main Outcome MeasuresProtein expression of GLUT4, GLUT1, and IR were determined by western blot.ResultsGLUT4 was exclusively expressed in the BM, and IR was predominantly expressed in the MVM, with increasing expression across gestation. BM GLUT1 expression was increased and BM GLUT4 expression was decreased in women with obesity delivering macrosomic babies. In placental villous explants, incubation with insulin stimulated Akt (S473) phosphorylation (+76%, P = 0.0003, n = 13) independent of maternal BMI and increased BM GLUT4 protein expression (+77%, P = 0.0013, n = 7) in placentas from lean women but not women with obesity.ConclusionWe propose that maternal insulin stimulates placental glucose transport by promoting GLUT4 trafficking to the BM, which may enhance glucose transfer to the fetus in response to postprandial hyperinsulinemia in women with normal BMI.

Polarized properties of thyroid cells: A study with cultured porcine cells

1987 ◽  
Vol 116 (1_Suppl) ◽  
pp. S220-S224 ◽  
Author(s):  
Jean Mauchamp ◽  
Odile Chabaud ◽  
Marianne Chambard ◽  
Corinne Gerard ◽  
Claude Penel ◽  
...  
Keyword(s):  
Cell Layer ◽  
Culture Conditions ◽  
Thyroid Cell ◽  
Apical Surface ◽  
Cell Plasma Membrane ◽  
Basal Surface ◽  
Thyroid Cells ◽  
Cell Plasma ◽  
Apical Compartment ◽  
Cell Layers

Abstract. In primary culture porcine cells form polarized cell layers. We have designed culture conditions in which we can have access to only one side of the cell layer, either the apical or the basal surface. In addition, using culture chambers with permeable bottom we can have access to either side of the cell layer which separates two compartments. Using these organized systems we have shown that the iodide concentrating mechanism and the TSH-reseptor adenyl cyclase complex are localized on the basolateral domain of the thyroid cell plasma membrane. We also demonstrated the existence on the apical surface of an amiloride sensitive sodium uptake. Finally we observed that about 10% of newly synthesized thyroglobulin appears to be secreted directly into the basal compartment, 90% being secreted in the apical compartment.

scholarly journals Ultrastructural features of the follicular wall in developing follicles of the sexually immature ostrich (Struthio camelus)

2006 ◽  
Vol 73 (3) ◽  
Author(s):  
M-C. Madekurozwa ◽  
W.H. Kimaro
Keyword(s):  
Granulosa Cell ◽  
Actin Filaments ◽  
Plasma Membranes ◽  
Cell Layer ◽  
Primordial Follicles ◽  
Struthio Camelus ◽  
Zona Radiata ◽  
Ultrastructural Characteristics ◽  
Theca Externa ◽  
Cytoplasmic Processes

The ultrastructure of the follicular wall in primordial, previtellogenic and vitellogenic follicles of the sexually immature ostrich is described in the present study. The follicular wall consists of a zona radiata, granulosa cell layer, basal lamina and thecal layer. Cytoplasmic processes from the plasma membranes of the granulosa cell layer and the ovocyte form the zona radiata in previtellogenic and vitellogenic follicles. The granulosa cell layer transforms from simple cuboidal epithelium in primordial follicles to simple columnar or pseudostratified columnar epithelium in previtellogenic and vitellogenic follicles. Transosomes were observed along the apical and lateral plasma membranes of granulosa cells. The thecal layer in previtellogenic and vitellogenic follicles consists of interna and externa components. The fibroblasts in the theca externa contain microfilaments, which are thought to be actin filaments. The study revealed ultrastructural features, which are associated with the transportation of yolk precursors and nutrients into the ovoplasm. In addition, the study indicates that, although the cells in the theca externa contain microfilaments, they do not possess the ultrastructural characteristics of smooth muscle cells.

Memoirs: Studies on the Golgi Apparatus in Gland-Cells

1926 ◽  
Vol s2-70 (277) ◽  
pp. 75-112
Author(s):  
ROBERT H. BOWEN
Keyword(s):  
Salivary Gland ◽  
Golgi Apparatus ◽  
Secretory Granules ◽  
Submaxillary Gland ◽  
Mucous Cells ◽  
Secretory Cycle ◽  
Golgi Bodies ◽  
Gland Cells ◽  
Structural Differences ◽  
Marked Tendency

Discussion of the results here reported will be postponed to a later paper, pending the completion of two other studies on the Golgi apparatus in gland-cells. But by way of summary, attention may here be called to the following points which in part furnish a general corroboration of the results of other recent work on the Golgi apparatus in gland-cells, and in other respects extend the work of previous writers in a number of directions. 1. In gland-cells of both serous and mucous types, the Golgi material undergoes a very extensive hypertrophy in the earlier stages of the secretory cycle. 2. There is a marked tendency in cells of the serous type for the Golgi apparatus to be extended throughout the mass of developing granules, while in mucous cells the apparatus tends to maintain a more compact and peripheral location. This is apparently correlated with the fact that in mucous cells the secretory granules are completed very soon after their formation, while in serous cells the whole content of granules seems to progress gradually toward a simultaneous completion. 3. The Golgi apparatus in the salivary gland of an invertebrate (Limax) has been shown to consist of the scattered Golgi bodies characteristic of many invertebrate tissues. 4. The topographical and structural differences in the Golgi apparatus of different types of gland-cells have made possible the demonstration that: (a) The demilune cells of the submaxillary gland are distinct from the predominant mucous cells, and indeed are probably of a serous nature. (b) The cells of the pulmonate salivary gland are of two types, mucous and serous, between which, at least in their active stages, no interchangeable relations exist. 5. In all the types of gland-cells examined, a very close topographical relation was found between the Golgi material and the developing secretory granules.

scholarly journals Mice Expressing Myc in Neural Precursors Develop Choroid Plexus and Ciliary Body Tumors

2018 ◽  
Vol 188 (6) ◽  
pp. 1334-1344 ◽  
Author(s):  
Morgan L. Shannon ◽  
Ryann M. Fame ◽  
Kevin F. Chau ◽  
Neil Dani ◽  
Monica L. Calicchio ◽  
...  
Keyword(s):  
Choroid Plexus ◽  
Ciliary Body ◽  
Neural Precursors

Extrarenal tissue distribution of CHIP28 water channels by in situ hybridization and antibody staining

1994 ◽  
Vol 266 (4) ◽  
pp. C893-C903 ◽  
Author(s):  
H. Hasegawa ◽  
S. C. Lian ◽  
W. E. Finkbeiner ◽  
A. S. Verkman
Keyword(s):  
In Situ Hybridization ◽  
Epithelial Cells ◽  
Tissue Distribution ◽  
Choroid Plexus ◽  
Ciliary Body ◽  
Fluid Transport ◽  
Pancreatic Acini ◽  
Antibody Staining ◽  
Strong Hybridization

This study is an extension of in situ hybridization experiments showing expression of mRNA encoding CHIP28 in selected epithelial or endothelia in spleen, colon, lung, and eye (H. Hasegawa, R. Zhang, A. Dohrman, and A. S. Verkman. Am. J. Physiol. 264 (Cell Physiol. 33): C237-C245, 1993). Additional tissues from rat were screened by in situ hybridization, and tissues from rat and humans were stained with a polyclonal anti-CHIP28 antibody. Northern blot showed the 2.8-kilobase mRNA encoding CHIP28 in kidney, lung, and heart. In situ hybridization showed strong hybridization in epithelial cells in choroid plexus, iris, ciliary body, and lens and in epithelial and subepithelial layers of trachea. Except for colonic crypts, specific hybridization was not observed in the gastrointestinal tract, liver, thyroid gland, and muscle. Immunoblot of tissues from exsanguinated rats showed immunoreactive CHIP28 protein in kidney, lung, trachea, and heart. In fixed frozen rat and/or human tissues, the anti-CHIP28 antibody stained epithelial cells in kidney proximal tubule and thin limb of Henle, lung alveolus, bronchial mucosa and glands, choroid plexus, ciliary body, iris, lens surface, colonic crypt, sweat gland, pancreatic acini, gallbladder epithelium, and placental syncytial trophoblast cells. Endothelial cells were stained in many tissues. These studies indicate a wide and selective CHIP28 tissue distribution, suggesting an important role for CHIP28 in fluid transport. The absence of CHIP28 in many nonrenal membranes believed to be water permeable suggests the existence of non-CHIP28 water transporters.

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