Search PubMed⌕ Search

Biomedical subjects

K Omori

Publications and source records attributed to K Omori.

At least 181 records · Page 10Linked to original sources
PubMed1989

Quantitative immunocytochemical localization of Na+,K+-ATPase in rat ciliary epithelial cells.

Ultrastructural localization of Na+,K+-ATPase in rat ciliary epithelium was investigated quantitatively by the protein A-gold technique, using an affinity-purified antibody against the alpha-subunit of Na+,K+-ATPase. Immunoblot analysis showed that the antibody bound specifically to the alpha-subunit of Na+,K+-ATPase in the ciliary body. Gold particles were found mainly on the basolateral surfaces of both the pigmented epithelial (PE) and nonpigmented epithelial (NPE) cells with an approximately twofold higher labeling density in the PE cells. A few gold particles were also found on the apical and ciliary channel surfaces of the PE cells, whereas no significant binding was found on the apical surfaces of the NPE cells. The basolateral surfaces of PE and NPE cells are markedly infolded and are much greater in area than the apical surfaces. This means that Na+,K+-ATPase is almost exclusively located on the basolateral surfaces of both the NPE and PE cells. We suggest that the Na+,K+-ATPase of both the NPE and PE cells play an important role in the formation of aqueous humor.

Animals↗
PubMed1987

Solubilization, purification, and characterization of (H+, K+)ATPase from hog gastric microsomes.

The (H+,K+)ATPase-enriched microsomal fraction prepared from hog gastric mucosa by sucrose density gradient centrifugation was effectively solubilized with Emulgen, with apparent preservation of the enzyme activity, and then the ATPase was highly purified by polyethylene glycol fractionation, and Blue Sepharose CL-6B and amino-hexyl Sepharose chromatographies. The purified enzyme showed a single band, with an apparent molecular mass of approximately 94 kDa, on SDS-PAGE, and exhibited both K+-ATPase and K+-stimulated-p-nitrophenyl phosphatase (pNPPase) activities. The optimum pH for the ATPase activity was 7.0. Amino acid analysis of the purified enzyme showed that it contains a large amount of hydrophobic amino acid (42%) and a small amount of glucosamine and galactosamine. The rabbit antibody monospecific for the ATPase, in the Ouchterlony double immunodiffusion and Western blotting tests, markedly inhibited both the K+-ATPase and K+-pNPPase activities.

Adenosine Triphosphatases↗
PubMed1987

Quantitative immunoelectron microscopic localization of (Na+,K+)ATPase on rat exocrine pancreatic cells.

Distribution of (Na+,K+)ATPase in rat exocrine pancreatic cells was investigated quantitatively by immunoelectron microscopy using the post-embedding protein A-gold technique. We found that in acinar and duct cells (Na+,K+)ATPase exists on both the luminal and the basolateral surfaces, with higher particle density on the luminal surface (4.4 times in the acinar cells and 5.6 times in the duct cells). According to Bolender (J Cell Biol 61:269, 1974), the luminal surface represents only 5% of the total cell surface of an average pancreatic acinar cell. It is roughly estimated, therefore, that approximately 80% of the plasma membrane (Na+,K+)ATPase in the acinar cells exists on the basolateral surface. When the acinar and duct cells were compared, more than twice as many particles were found on acinar cells than on duct cells. The enzyme existed on all the cell surfaces, preferentially on the microvilli or on the cell membrane folds, and no clustering was detected. We suggest that the (Na+,K+)ATPase on the basolateral surface is mainly responsible for the extrusion of a large number of sodium ions that are incorporated into the cytoplasm accompanying the secondary active transport of various organic substances and inorganic ions, whereas that on the luminal surface is responsible for active extrusion of sodium ions that are partially responsible for the fluid secretion of the pancreatic cells.

Animals↗
PubMed1987

Quantitative immunoelectron microscopic localization of (Na+,K+)ATPase in rat parotid gland.

Distribution of (Na+,K+)ATPase on the cell membranes of acinar and duct cells of rat parotid gland was investigated quantitatively by immunoelectron microscopy using the post-embedding protein A-gold technique. In acinar cells, ATPase was localized predominantly on the basolateral plasma membranes. A small but significant amount of (Na+,K+)ATPase was, however, detected on the luminal plasma membranes, especially on the microvillar region of the acinar cells; the surface density on the luminal membrane was approximately one third of that on the basolateral membranes. In duct cells, many gold particles were found on the basolateral membrane, especially along the basal infoldings of the plasma membranes, whereas no significant gold particles were found on the luminal plasma membranes, suggesting unilateral distribution of ATPase in duct cells. We suggest that in acinar cells sodium ion is not only transported paracellularly but is also actively transported intracellularly into the luminal space by the (Na+,K+)ATPase located on the luminal plasma membranes, and that water is passively transported to the luminal space to form a plasma-like isotonic primary saliva, while in the duct cells the same ion is selectively re-absorbed intracellularly by (Na+,K+)ATPase found in abundance along the many infoldings of the basal plasma membranes, thus producing the hypotonic saliva.

Animals↗
PubMed1986

Quantitative immunoferritin localization of leucine aminopeptidase on canine hepatocyte cell surface.

Rabbit monospecific antibody against canine kidney leucine aminopeptidase (LAP) (EC.3.4.11.2) specifically immunoprecipitated kidney and also liver LAP activity from corresponding plasma membrane preparations previously solubilized with Triton X-100. Immunological specificity of the antibody was also shown by immunoblotting of LAP from canine and rat liver plasma membranes and by electrophoretic analyses of the precursor forms in MDCK cells. Canine liver was pre-fixed by perfusion with 0.6% glutaraldehyde and the dissociated liver cells were prepared without losing their polarized structure (22). They were incubated with ferritin antibody conjugates against canine kidney LAP at the saturation level, and the distribution of ferritin particles on the three surface domains of the hepatocytes was investigated quantitatively by counting ferritin particles on the cross-sectional profiles of these surfaces. Our analysis clearly indicated that LAP exists only on the bile canalicular surface, and no significant number of ferritin particles was detected either on the sinusoidal front or on the lateral surface. Ferritin particles were distributed homogeneously both on the microvillar and intermicrovillar regions. All the bile canalicular surface domains of all the hepatocytes were heavily labeled with ferritin particles, without exception.

Animals↗
PubMed1986

The (Na+, K+)ATPase of rat kidney: purification, biosynthesis, and processing.

(Na+, K+)ATPase was purified from rat renal outer medulla by concanavalin A- and wheat germ agglutinin-lectin Sepharose affinity chromatographies. The antibody, which was raised in rabbits, markedly inhibited ATPase activity. The monospecificity of this antibody was assayed by the Ouchterlony double immunodiffusion and Western blotting tests. The endoplasmic reticulum (ER)-rich, and Golgi-rich subfractions were prepared from the rat kidney microsomal fraction by sucrose density gradient centrifugation. On the immunoblot, the molecular weight of the alpha subunit in both fractions was 95 kilodalton (Kd); whereas, that of the beta subunit was 50 Kd in the ER-rich fraction and 54 Kd in the Golgi-rich fraction. When treated with endoglucosidase H, the 50 Kd component was converted to 38 Kd, but the 54 Kd component was endoglucosidase H resistant. These results suggest that the beta subunit (38 Kd) is glycosylated cotranslationally in the ER (50 Kd) then is converted to the mature type subunit (54 Kd) in the Golgi apparatus.

Amino Acids↗
PubMed1986

[Autosomal translocation and associated male infertility].

Four balanced autosomal reciprocal translocations were found through mitotic chromosome analysis among 72 subfertile males, 27 with azoospermia and 45 with sperm counts below 40 X 10(6)/ml. They were 46, XY, t(3; 20; 21) with azoospermia, 46, XY, t(14; 21) with sperm counts below 1 X 10(6)/ml, 46, XY, t(1; 19) lqh+ with azoospermia and 46, XY, t(3; 16) with sperm counts 27 X 10(6)/ml. Histological, cytogenetic and hormonal analysis were performed. Testicular biopsies from the first 3 carriers revealed complete spermatogenic arrest at the spermatocyte stage and meiotic studies of the same biopsies showed severe reduction in numbers of cells in 2nd meiotic division. In spite of severely defective spermatogenesis, serum gonadotropins of the carriers were within normal range, except for LH of the 4th case. Other chromosomal aberrations observed were 5 Klinefelter's syndrome, 2 autosomal minor variants (46, XY, 15p+ and 46, XY, 14s+) and 1 small Y.

Chromosomes, Human, 1-3↗