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Biomedical subjects

T Sakata

Publications and source records attributed to T Sakata.

At least 541 records · Page 30Linked to original sources
PubMed1981

Luminal mucin in the large intestine of mice, rats and guinea pigs.

The luminal and epithelial mucin was studied histochemically in the large intestine of mice (Mus musculus), rats (Rattus rattus) and guinea pigs (Cavia porcellus) using freeze-substitution and vapor-fixation methods. Neutral mucin decreased and acid mucin increased in the epithelium from the cecum to the distal colon. Vacuolated cells contained more acid mucin than goblet cells. Luminal mucin always contained neutral mucin, which formed the main constituents in the cecum and in the proximal colon. Sialo-mucin increased from the cecum to the distal colon. Sulfo-mucin appeared only in the distal colon. Except in the cecum a luminal mucin layer (LML) was found at the epithelial surface. In the proximal colon LML was not entirely continuous and varied in composition and thickness (182.4 +/- 170.1, 150.5 +/- 110.4, 30.0 +/- 28.9 (micrometer), in mice, rats and guinea pigs, respectively), and contained many bacteria. In the distal colon LML was compact, homogeneous and thin (33.6 +/- 18.8, 16.1 +/- 7.3, 29.1 +/- 20.0 (micrometer), in mice, rats and guinea pigs, respectively) containing few bacteria. Possible functions of the luminal mucin and their regional differentiations were discussed.

Animals↗
PubMed1981

Influence of short-chain fatty acids and osmolality on mucin release in the rat colon.

The influence of short-chain fatty acids (SCFA) and osmolality on mucin release in the rat colon was studied histochemically by determining number of stained mucin-containing cells. SCFA did not significantly influence the number of cells staining for mucin. Hypertonic solutions (360 mosm/l) did not affect mucin release in the proximal colon, but stimulated mucin release in the distal colon. Solutions of lower osmolality (300 or 250 mosm/l) caused a considerable release of mucin from goblet cells as well as vacuolated cells in both the proximal and the distal colon; the lower the osmolality, the more mucin was released. The mucosa of the distal colon was conspicuously affected by solutions of lower osmolality. The influence of osmolality on mucin release was entirely local.

Animals↗
PubMed1980

Stimulatory effect of insulin on ruminal epithelium cell mitosis in adult sheep.

1. The rumen adapts to increased food intake by the hyperplasia of epithelial cells. 2. Volatile fatty acids (VFA) stimulate cell mitosis of sheep ruminal epithelium in vivo. 3. Since VFA generally inhibit cell proliferation in vitro insulin was proposed in this study as the possible mediator of the mitotic stimulation in vivo. 4. Infusions (6 h) of insulin (0.125 U/kg per h) plus glucose (300 mg/kg per h) (n 5), and glucose alone (300 mg/kg per h) (n 2) resulted in higher mitotic index of biopsied rumen epithelium (MI) during 3 or 6 to 24 h after the start of infusion, and higher plasma immunoreactive insulin (IRI) and higher plasma glucose (PG) during the infusion. 5. Insulin plus glucose infusion showed higher MI, higher IRI, and lower PG than glucose infusion. 6. Sheep infused with saline for 6 h (n 1) showed no marked changes in MI, IRI, and PG. 7. Increased IRI by insulin plus glucose or glucose alone infusion was considered to stimulate cell proliferation in rumen epithelium. 8. Other possible mediations were discussed.

Animals↗
PubMed1980

High-pressure liquid chromatography of free nucleotide patterns in normal and abnormal keratinocytes.

A method for analyzing free nucleotides in the epidermis of the guinea pig is presented. Free nucleotides were extracted by using a methylalethanol mixture, and the analysis was carried out by high-pressure liquid chromatography on a column of Lichrosorb-NH2 with a single buffer of potassium phosphate. The concentration of total free nucleotides in the epidermis is about 4 times greater than that in the liver, kidney, spleen, or intestinal epithelium.l The free nucleotide level is markedly elevated in the hyperkeratotic epidermis induced by n-hexadecane. The alternation of free nucleotides in hyperkeratotic epidermis is discussed in relation to nucleic acid content, DNase, disc-electrophoretic properties of DNase, and salvage pathway enzymatic activity. Significant increases in the enzyme activity of the salvage pathway and in neutral DNase were observed in the hyperkeratotic stage. However, the DNA content and acid DNase activity were decreased. It is suggested that the pool size of free nucleotides in the epidermis is affected by the salvage enzyme system.

Alkanes↗
PubMed1980

Drug-induced liver injury and microsomal arylamidase activity in needle biopsy of human liver.

The relation between the activities of arylamidase (one of the non-specific carboxylesterases) located exclusively in smooth endoplasmic reticulum (SER), and microscopical changes of the hepatocytes, was studied in three patients treated with phenobarbital and twenty-five patients injured by various other drugs. A micro-method was used for the determination of the enzyme activity in small pieces of liver (5-15 mg) obtained by needle biopsy. The arylamidase activity in seven normal livers was 0.43 +/- 0.05 (SD) nmol benzylhydrazine/micron protein/hr formed from isocarboxazid. The mean value in the livers treated with phenobarbital was statistically different from the value before phenobarbital treatment (P less than 0.05). Of sixteen cytotoxic type samples, seven showed low activity and eight high activity, respectively. Of the seven mixed-type samples, three showed mildly low activity and four normal activity. The frequency of the cytotoxic type is statistically different from that of the cholestatic (mixed and pure cholestatic) type comparing the abnormal activity with normal activity (P less than 0.05). The degree of enzyme activity was related to changes such as pyknosis, enlarged nuclei and centrilobular zonal necrosis. The ultrastructure of the material taken from three patients after phenobarbital treatment and one patient with ibuprofen-induced injury showed prominent increase and vesiculation of SER respectively. The study shows that drug-induced liver injury is closely related to the activity of SER, and that the changes in hepatocytes in cytotoxic type may result from the functional abnormality of SER.

Adult↗