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H Esumi

Publications and source records attributed to H Esumi.

155 records · Page 9Linked to original sources
PubMed1980

Absence of albumin mRNA in the liver of analbuminemic rats.

Albumin synthesis in the liver of analbuminemic rats, established as a strain from a stock of Sprague-Dawley rats, was examined in vivo by labeling protein by intraperitoneal injection of L-[3H]leucine. Albumin was not synthesized in the liver of analbuminemic rats, whereas its synthesis amounted to about 14% of the total protein synthesis in the liver of normal rats. The RNA content and size distribution of the total polysomes in the liver of analbuminemic rats were not significantly different from those of normal rats. However, no functional mRNA coding for albumin was found in poly(A)-containing RNA from the liver of analbuminemic rats when tested with a cell-free translation system derived from rabbit reticulocytes. Moreover, the amount of the RNA sequence that could hybridize to purified albumin cDNA was more than 750 times greater in the liver of normal rats than in that of analbuminemic rats.

Animals↗
PubMed1979

Further studies of the effect of pepstatin on ascites accumulation in tumor-bearing mice.

Studies were done of the effect of pepstatin on ascites accumulation in mice bearing MM46, Ehrlich, CCM, SN36, L1210, and NTF ascites tumors. When pepstatin was injected subcutaneously at 80 mg/kg body wt before ascites accumulation, it inhibited the accumulation in all strains of the tumors tested. In MM46, CCM and NTF tumor strains there was also a decrease in the tumor cell numbers following pepstatin treatment. Kinetic studies on ascites accumulation with tumor strain MM46 demonstrated that even when pepstatin was injected after ascites accumulation it reduced the ascites volume. A dose-dependent effect was observed in this tumor strain when pepstatin was injected both before and after ascites accumulation. The results confirm previous studies of pepstatin's ability to retard ascites in L1210 and P-815Y ascites tumors and also broaden the concept of the mechanisms by which petstatin may be acting.

Animals↗
PubMed1978

Purification and properties of an acid protease from human ascitic fluid.

An acid protease was isolated from the ascitic fluid of a patient with ovarian cancer. It was purified about 400-fold to homogeneity by ammonium sulfate fractionation, gel filtration on Sephadex G-200 and DEAE-cellulose column chromatography. Its molecular weight was calculated to be 28 000 by gel filtration, and its isoelectric points was found to be pH 4.1. It showed similar activities on acid-denatured bovine serum albumin and on acid-denatured bovine hemoglobin, and its optimal pH for both substrates was 3.0. Sulfhydryl compounds and metal ions had no apparent effects on this enzyme, but pepstatin was strongly inhibitory.

Ascitic Fluid↗
PubMed1977

Further studies on the effect of leupeptin, a protease inhibitor, on induction of bladder tumors in rats by N-butyl-N-(4-hydroxybutyl)nitrosamine.

The effect of a microbial protease inhibitor, leupeptin, on the induction of urinary bladder tumors in W rats by N-butyl-N-(4-hydroxybutyl)nitrosamine (BBN) was examined. Three groups of animals were given 0.01% BBN in their drinking water for 12 weeks. A basal powder diet supplemented with 0.1% leupeptin was given to group A throughout the experiment and to group B when BBN administration was stopped. Group C was given the basal diet without leupeptin throughout the study. The total preservation period was 40 weeks. Results clearly showed that when leupeptin was given during the promotion step of bladder carcinogenesis (as in group B), it increased the size of tumors and the incidences of cancer and invasion. When leupeptin was given throughout the experiments, its effect was counteracted (as in group A).

Animals↗
PubMedDate not supplied

[HIF-1alpha, HIF-2alpha and VHL mRNA expression in different cell lines during hypoxia].

Hypoxia inducible factor-1alpha (HIF-1alpha) mRNA expression is significantly decreased under hypoxia in different cell lines exposed directly to hypoxia or treated with dimethyloxalylglycine which mimics hypoxic effects under normoxic conditions. However, the decreased expression of HIF-1alpha mRNA is accompanied by an increase of HIF-1alpha protein (pHIF-1alpha) level as well as by overexpression of known HIF-dependent genes (VEGF, Glut1, PFKFB-3 and PFKFB-4) under hypoxic conditions or with the use of dimethyloxalylglycine. Expression of HIF-1alpha mRNA also depends on iron because desferrioxamine and cobalt chloride produce similar to hypoxia effects on the levels of this mRNA. It was shown that HIF-1alpha mRNA expression did not change significantly in some cell lines (SKBR3, MDA-MB468 and BT549) under hypoxia. However, in these cell lines hypoxia decreases expression of HIF-2alpha mRNA, another member of HIF-alpha gene family, as a result of cell specific regulation of HIF-alpha genes under hypoxia. Moreover, hypoxia slightly induces expression of PFKFB-4 mRNA in SKBR3, MDA-MB468 and BT549 as compared to other cell lines where this effect of hypoxia was much stronger and adaptation to hypoxia is controlled by HIF-1alpha. Hypoxia slightly reduces expression of tumor suppressor VHL which targets HIF-1alpha for ubiquitination. Thus, our results clearly demonstrated down regulation of HIF-1alpha or HIF-2alpha in different cell lines by hypoxia.

Amino Acids, Dicarboxylic↗