PubMed Health⌕ Search

Biomedical subjects

S Iseki

Publications and source records attributed to S Iseki.

At least 73 records · Page 4Linked to original sources
PubMed1991

Ontogenic appearance of three fatty acid binding proteins in the rat stomach.

With the use of specific antibodies against three structurally different fatty acid binding proteins (FABPs), viz, liver FABP (L-FABP), heart FABP (H-FABP), and intestinal FABP (I-FABP), the localization and relative amount of the immunoreactive proteins were determined by immunoblotting and immuno-cytochemistry in the gastric epithelium of rats during prenatal and postnatal development. H-FABP immunoreactivity was first detected at embryonic day 20 (E20), with predominant localization in the parietal cells, whereas I-FABP immunoreactivity was detected at the day of birth in the surface mucous cells. Both immunoreactivities were continuously localized in the same cell types with increasing intensity into adulthood. In contrast, the immunoreactivity for L-FABP showed remarkable changes in intensity and localization during development of the rat stomach. It was first detected in the surface mucous cells of E19. In the first 2 weeks of postnatal life, i.e., the suckling period, L-FABP immunoreactivity reached a peak in intensity and was localized not only in the surface mucous cells, but also in some of the parietal cells, brush cells, and endocrine D cells. In the following few weeks of weaning, the reactivity of surface mucous cells and parietal cells disappeared, leaving only a small amount of total L-FABP immunoreactivity in the adult stomach, which was localized exclusively in the brush cells and D cells. These results revealed that the appearance of the three types of FABPs in the rat stomach is specific to cell types and developmental stages.

Animals↗
PubMed1991

Postnatal development of the brush cells in the common bile duct of the rat.

The postnatal development of brush cells in the distal segment of the common bile duct of the rat was examined with respect to cell number and immunoreactivity for liver fatty acid-binding protein (L-FABP). The brush cells, distinguishable from the principal cells by scanning electron microscopy, first appeared in the common bile duct 4 weeks after birth. They showed a remarkable increase in number, with a sex difference in time, i.e., between 8 and 12 weeks in the male and between 10 and 14 weeks in the female. In both sexes, the frequency of brush cells reached approximately 30% of total epithelial cells by 16 weeks and remained constant until 40 weeks of age. Cells with positive immunoreactivity for L-FABP first appeared in small numbers at 8 weeks. Immuno-electron microscopy revealed that all immunoreactive cells were brush cells. They increased in number gradually from 16 to 40 weeks with no sex difference. At 40 weeks, the immunoreactive cells reached approximately 7.5% of total epithelial cells, corresponding to one-fourth of the number of brush cells. These results indicate that the occurrence of the brush cell population in the common bile duct is a late event in the postnatal development of the rat and that its functional maturation progresses with aging.

Animals↗
PubMed1991

Expression of transforming growth factor beta 1 in the submandibular gland of the rat.

We employed immunocytochemical and in situ hybridization techniques to study the expression of transforming growth factor beta 1 (TGF-beta 1) in rat submandibular gland. Immunoreactivity for TGF-beta 1 was observed in the cells of granular convoluted tubules (GCTs), striated ducts, and excretory ducts, whereas it was absent in the intercalated ducts and secretory acini in both male and female rats. Immunoelectron microscopy revealed the ultrastructural localization of TGF-beta 1 in the secretory granules of GCT cells. On the other hand, signals for rat TGF-beta 1 mRNA were abundant in the GCT and striated duct cells but were lacking in the excretory duct cells. These results provided evidence for the production of TGF-beta 1 in the GCTs and striated ducts of rat submandibular gland.

Animals↗
PubMed1990

An immunocytochemical study on the occurrence of liver fatty-acid-binding protein in the digestive organs of rats: specific localization in the D cells and brush cells.

Rat liver fatty-acid-binding protein (L-FABP) was originally isolated from the liver parenchymal cells and later found also in the intestinal absorptive cells. By light- and electron-microscopic immunocytochemistry we examined the distribution of L-FABP in the entire digestive system of the rat and revealed two other cell types, i.e. the endocrine D cell and the brush cell, to be specifically immunoreactive for L-FABP. The immunoreactive D cells, identified by the simultaneous immunoreactivity for somatostatin and by characteristic endocrine granules, were found in the stomach epithelium and pancreatic islets. The immunoreactive brush cells, identified by the ultrastructural features of cell apex, were found primarily in the stomach epithelium and also in the epithelia of the rectum and common bile duct. Almost all immunoreactive brush cells had a thin process in contact with the basement membrane. No secretory granules with dense cores similar to those of the endocrine cells were observed in the brush cells. The present findings reveal L-FABP to be a useful marker of the gastrointestinal D cells and brush cells, especially of the latter, confirming that the brush cell is a distinct entity different from any other cell types in the gastrointestinal epithelia. Furthermore, FABP may be involved in the specific functions of these cell types related to fatty acid metabolism.

Animals↗
PubMed1990

Light microscopic localization of hepatic fatty acid binding protein mRNA in jejunal epithelia of rats using in situ hybridization, immunohistochemical, and autoradiographic techniques.

An in situ hybridization technique using a [35S]-labeled oligonucleotide probe was employed, in combination with immunohistochemistry and autoradiography, to examine gene expression for hepatic fatty acid binding protein (FABP) in the jejunal epithelia from both fed and fasted rats. In rats fed ad libitum, immunoreactivity and mRNA signal for FABP were localized to the absorptive epithelial cells lining the villus, whereas they were absent in the crypt epithelial cells. The level of FABP mRNA was relatively low in the tip of the villus, although FABP immunoreactivity remained high in this area. Animals fasted for 3 days exhibited a downward shift of the lower boundary of the FABP-expressing cell population into the middle portion of the crypt, in terms of the immunoreactivity and the mRNA signal. The proliferative cell compartment of the crypt, as revealed by [3H]-TdR incorporation, showed no substantial change in size between the fed and fasted states. The present results provided evidence that (a) during the differentiation and upward migration of the absorptive epithelial cells, the expression of FABP gene begins at the crypt-villus junction and declines before the cells reach the villus tip, and (b) fasting induces an earlier expression of the FABP gene in the maturing crypt epithelial cells.

Animals↗
PubMed1989

Purification and characterization of a fatty-acid-binding protein from the gastric mucosa of rats. Possible identity with heart fatty-acid-binding protein and its parietal cell localization.

Fatty acid-binding protein (FABP) was purified from rat gastric mucosa by successive Sephadex G-75 chromatography, DEAE-cellulose chromatography and HPLC on an RP-2 (Merck) reversed-phase column. The purified stomach FABP migrated as a single band corresponding to an apparent molecular mass of 15 kDa on SDS/PAGE. Stomach FABP appeared to be identical with rat heart FABP, as judged from its electrophoretic mobility, amino acid composition and tryptic peptide map. In addition, the amino acid sequences of two selected tryptic peptides coincided completely with the rat heart FABP sequence deduced from that of cDNA. Stomach FABP showed immunochemical identity with rat heart FABP when tested with an antiserum against rat heart FABP. Immunohistochemically, stomach FABP was specifically stained with anti-(rat heart FABP) serum in parietal cells of the gastric mucosa. The results suggested that the primary structure of stomach FABP is identical with that of rat heart FABP, and showed that stomach FABP is localized in parietal cells of the gastric mucosa.

Amino Acid Sequence↗
PubMed1989

Immunocytochemical localization of hepatic fatty acid binding protein in the rat intestine: effect of fasting.

Localization of hepatic fatty acid binding protein (h-FABP) in the small and large intestines of rats was studied by light and electron microscopic histochemistry using the peroxidase-antiperoxidase (PAP) method. In the small intestine of rats fed ad libitum, an intense FABP immunoreactivity was confined to the absorptive epithelial cells of the villi, but not of the crypts. The lowest margin of the immunoreactive cell sheet was closer to the crypts in the proximal than in the distal portions of the small intestine. In the large intestine, FABP immunoreactivity was present in the surface epithelial cells, with higher intensity in the proximal than in the distal portions of the intestine. After fasting rats for two days, many crypt cells exhibited intense immunoreactivity for h-FABP, resulting in an extension of the lowest margin of the immunoreactive cell sheet deep into the crypts. Such expansion of the immunoreactive cell population was reversed by refeeding the animals. With regard to the intracellular localization of immunoreactivity in the jejunum, the basolateral portion of the cytoplasm exhibited a more intense immunoreaction than the apical portion in the majority of immunoreactive cells lining the villi, whether the animals were fed or fasted. The immunoreactive products appeared in the cytoplasmic matrix without association with any subcellular structures.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1989

Specific localization of hepatic fatty acid-binding protein in the gastric brush cells of rats.

An immunocytochemical study by light- and electron microscopy using the antibody against rat hepatic fatty acid-binding protein (FABP) revealed the brush cells in the gastric epithelium of rats to be intensely immunoreactive. The immunoreactive cells were present in a group in the distal wall of the groove between forestomach and glandular stomach, as well as scattered singly in the surface and foveolar epithelia of the glandular stomach. Almost all immunoreactive brush cells had a thin basal process in contact with the basement membrane. No secretory granules with dense cores, similar to those of endocrine cells, were observed in the brush cells. The specific appearance of FABP-immunoreactivity in the brush cell indicates that this cell type is a distinct entity from other epithelial cells in the stomach and that FABP is a useful histochemical marker of the brush cells. FABP may be involved in the specific function(s) of this cell type related to fatty acid metabolism.

Animals↗
PubMed1989

A longitudinal study on the expression of the opsin gene in the degenerating retina of C3H/He mice.

By a combination of immunohistochemistry and in situ hybridization using a 35S-labeled opsin cDNA probe, it was revealed in rd mutant C3H/He mice that opsin mRNA is not detectable in photoreceptor cells which still exhibit opsin-immunoreactivity at later stages of retinal degeneration. This indicates that the photoreceptor cells of rd mutant mice cease to express the opsin gene at earlier stages of retinal degeneration.

Animals↗
PubMed1988

Immunocytochemical localization of hepatic fatty acid binding protein in the liver of fed and fasted rats.

The immunocytochemical localization of fatty acid binding protein (FABP) of liver type was studied at light and electron microscopic levels by the peroxidase-antiperoxidase (PAP) method using a specific polyclonal antibody against FABP in the liver of fed and fasted rats. In the liver of rats fed ad libitum, the intense immunoreactivity was confined to portions of the liver cell cytoplasm adjacent to the glycogen area. After 2-days' fasting, such a focal intracellular localization of the immunoreactivity was abolished, in association with the disappearance of the glycogen area, and was replaced by a diffuse distribution of the immunoreactivity throughout the cytoplasm, with higher intensity at the periphery of the cells. In liver cells exhibiting an overall hypertrophy of smooth endoplasmic reticulum (SER) induced by the treatment of fasted rats with phenobarbital, the peripheral localization of FABP immunoreactivity remained unchanged compared with that obtained in the case of fasting alone, and the immunoreactivity did not occur in association with the proliferated SER in the central cytoplasm. These results suggest that FABP, although cytosolic in nature, changes its localization within the liver cells in response to the general metabolic alterations caused by the starvation, inferring that FABP is intimately involved in the intracellular transport and metabolism of free fatty acids.

Animals↗
PubMed1987

Incorporation of NAD into fixed cell nuclei.

Incorporation of NAD into the nuclei was determined autoradiographically in cultured HeLa cells and in cryostat sections of rat organs by incubating them with 3H-NAD after fixation with various agents. Acetone fixation was the best to render the cells permeable to NAD while preserving the cell's enzymatic activity to incorporate NAD into nuclear macromolecules. Various evidence supported that such incorporation of NAD is due mostly to the synthesis of poly(ADP-ribose) on chromatin proteins. In the sections of rat jejunum and esophagus the rate of NAD incorporation was higher in the actively proliferating cell nuclei than in the differentiated cell nuclei within the same epithelia. These results suggested that the capacity of the cells to synthesize poly(ADP-ribose) is associated with cell growth and differentiation.

Autoradiography↗
PubMed1986

DNA strand breaks in rat tissues as detected by in situ nick translation.

The nick-translation procedure without external addition of DNase was performed in situ on sections of various rat organs to detect possible DNA single-strand breaks (nicks) in normal tissues. The freshly frozen sections were briefly fixed in ethanol/acetone and nick-translated in the presence of E. coli DNA polymerase I. A significant difference in the amount of nuclear reaction was found among the different cell populations as detected by autoradiography following incorporation of tritiated TTP as well as by histochemical staining following incorporation of biotin-dUTP into nuclei. Such incorporation of triphosphates was localized in the DNA and was entirely dependent on E. coli DNA polymerase I. The nuclei with the highest reactivity were found in skeletal muscle cells, lymphocytes in various lymphatic organs, the proliferative cells in the gastrointestinal tract, stratified squamous epithelial cells, duct epithelial cells of salivary gland and the maturing spermatids in the seminiferous tubules. These results suggest that, under the conditions adopted, the cells in various tissues reveal different chromatin structures resulting in varying rates of nick translation reaction. Such difference(s) in chromatin structure, presumably including that in the number of DNA single-strand breaks or in the level of endogenous nuclease activity, may be associated with the mechanisms involved in cell growth and differentiation.

Animals↗
PubMed1986

Methyl green-pyronin stain distinguishes proliferating from differentiated nonproliferating cell nuclei after acid denaturation of DNA.

We applied methyl green-pyronin (MG-P) stain, which is usually used for the selective staining of DNA and RNA, to frozen sections of rat jejunal and esophageal mucosa, following digestion with RNase and treatment with various concentrations of HCl. The pyroninophilia of the nuclei increased with increasing strength of the acid, but the susceptibility of the nuclei to acid differed among cell populations. In the jejunal epithelium, at an appropriate acid strength the nuclei in the crypts of Lieberkuhn were less acid-sensitive and remained blue-green, whereas those in the villi were more pyroninophilic and stained lavender. Under the same conditions, the nuclei in the basal layer of the esophageal epithelium were blue-green and those in the spinous and granular layers were increasingly lavender. These results suggest that in cell-renewal systems the differentiated, nonproliferating cells are more sensitive to acid denaturation of DNA than the undifferentiated, actively proliferating cells. MG-P stain, which is able to distinguish double-stranded from single-stranded DNA, may be used as a tool to stain proliferating and nonproliferating cell nuclei differentially in tissue sections.

Animals↗
PubMed1985

Histochemical detection of DNA strand scissions in mammalian cells by in situ nick translation.

A method to visualize in situ of single strand scissions of DNA in fixed mammalian cells has been developed. Using the nuclear nick translation with biotin-labeled dUTP followed by binding to avidin-biotin-peroxydase complex, the nuclei of HeLa cells which had been treated with a DNA-damaging antibiotic bleomycin were specifically stained, implicating that the histochemical detection of single strand scissions (nicks) of DNA in fixed cells was completed without destroying the morphology, and without using autoradiography.

Biotin↗
PubMed1985

Effect of poly(adenosine diphosphate-ribose) polymerase inhibitors on neocarzinostatin-induced G2 delay in HeLa-S3 cells.

The antitumor antibiotic neocarzinostatin (NCS), which produces single-strand breaks in mammalian cell DNA in vivo, stimulated the activity of chromatin bound enzyme, poly(ADP-ribose) polymerase in HeLa-S3 cells. Because of the possible causal relationship between the poly ADP-ribosylation of chromatin protein and NCS-induced temporary G2 arrest in the cell cycle, several classes of inhibitors of poly(ADP-ribose) polymerase were examined to evaluate the effect on NCS-induced polymerase activity as well as on progression in the cell cycle of synchronized HeLa cells which had been treated with NCS in G2. Compared at the same concentration of 2 mM, the polymerase-inhibiting activity was larger in the order of thymidine, 3-aminobenzamide, nicotinamide, theophylline, and caffeine. Among these agents, caffeine, theophylline, and thymidine caused a reduction in the G2 delay in this order by stimulating the cells to undergo mitosis after NCS treatment. However, 3-aminobenzamide and nicotinamide were poor reducers, if any, of NCS-induced G2 delay. These results suggest that there is not a direct involvement of poly ADP-ribosylation of chromatin protein in the mechanism of NCS-induced G2 delay. The effect of caffeine on G2 delay will probably be independent of its activity as a poly(ADP-ribose) polymerase inhibitor.

Antibiotics, Antineoplastic↗
PubMed1983

Effect of butyrate on adenovirus infection in semipermissive cells.

Adenovirus 2 stimulated cellular DNA synthesis in quiescent cultures of semipermissive tsAF8 cells and 3T3 cells. Such stimulation was inhibited by Na-butyrate, which also inhibited viral DNA replication in tsAF8 cells. In addition, butyrate inhibited the expression of early regions E1A and E2 of adenovirus 2 in both tsAF8 and 3T3 cells, while it had little effect on permissive HeLa cells.

Adenoviruses, Human↗