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Biomedical subjects

K Ota

Publications and source records attributed to K Ota.

At least 739 records · Page 41Linked to original sources
PubMed1980

Influence of uremic middle molecules on blood cells.

Uremic middle molecular weight substances are obtained from the ultrafiltrate of plasma of uremic patients. Seven subfractions are isolated by chromatography using Sephadex G-15 and DEAE 25 A columns. Each subfraction is tested for its inhibitory effect upon lymphocyte blastogenesis and influence upon osmotic fragility of red blood cells. Consequently, subfractions c and d exert notable effects on both lymphocytes and red blood cells. The main constituents of subfraction d are aspartic acid, glycine, glutamine, and cysteine. It is concluded that uremic middle molecular substances have a deleterious effect upon blood cells. Therefore, hemofiltration, which is advantageous for the removal of middle molecular weight substances, is considered to be a method of choice for uremic patients.

Amino Acids↗
PubMed1980

Vitamin D and parathyroid hormone degradation by the kidney.

Parathyroid function is controlled by the regulation of hormone secretion as well as degradation, through the action of calcium and vitamin D derivatives. In order to clarify the relationship between vitamin D metabolism and parathyroid degradation system, parathyroid hormone (PTH)-degrading activities of the kidney were measured in vitamin D repleted and depleted rats given various derivatives of vitamin D. Kidney calcium content rose markedly in animals given 10 microgram/kg 1 alpha(OH) vitamin D3 and 1,000 microgram/kg dihydrotachysterol and PTH-degrading activity rose only in these animals, indicating a parallelism between kidney calcium content and PTH-degrading activity of the kidney tissue. These vitamin D derivatives also increased the PTH-degrading activity of kidney tissue when they were added in vitro.

Animals↗
PubMed1980

Specific binding of prolactin to the mammary gland and lactose synthesis in pregnant rats after removal of ovaries or ovaries and adrenals.

Ovariectomy performed at mid pregnancy increased the specific binding of 125I-prolactin to the mammary gland (expressed as cpm/mg DNA) in rats 40 hr after the operation. When adrenals were removed simultaneously at the time of ovariectomy, no increase in the specific binding was observed. An appreciable amount of lactose was found in all mammary glands of ovariectomized-adrenalectomized animals, though the content was less than half of that of the ovariectomized animals. The plasma level of prolactin in ovariectomized and ovariectomized-adrenalectomized rats was slightly higher than that in sham operated control rats, though the differences were not statistically significant. These results seem to indicate that the adrenal gland is necessary for the induction of the site of specific binding of prolactin in the mammary gland of the rat and that an increase in the circulating levels of prolactin does not seem to play an essential role in the initiation of milk synthesis in this species.

Adrenal Glands↗
PubMed1980

Radioimmunoassay of arginine vasopressin in human plasma and urine, a resin microcolumn method.

A new method was developed for the estimation of arginine vasopressin (AVP) in plasma and urine. Samples were extracted by a microcolumn of resin and assayed radioimmunologically using a highly sensitive antiserum to AVP. Ion-exchange resin, CG-50, H+ form, packed in a small column (diameter 4 mm, height 6 mm), was proved effective to remove the interfering substances and to concentrate the AVP in the sample. The application of 80% acid acetone successive to diluted HCl brought about a consistent recovery of AVP from the resin column. Recoveries were 66.4 +/- 8.5% for plasma and 85.4 +/- 9.7% for urine. In normal subjects plasma AVP levels were 3.9 +/ 0.3 pg/ml (mean +/- S.D.) in ambulatory states, 4.9 +/- ).6 after overnight fast, and 0.4 +/- 0.2 after water lading. High levels of 2.0 +/- 24.2 pg/ml were obtained in patinents with syndrome of inappropriate secretion of ADH (SIADH), low values of 0-1.8 pg/ml in diabetes inipidus. Urinary excretions of AVP were 117.4 +/- 59.4 ng/24/hr (mean +/- S.D.) in normal controls, 191 +/- 177.0/24 hr in SIADH, and 17.0 +/- 12.0/24 hr in diabetes insipidus.

Arginine Vasopressin↗
PubMed1980

Increase of antitumor effect on bleomycin by reduced nicotinamide adenine dinucleotide phosphate and microsomes in vitro and in vivo.

The DNA chain breakage effect of bleomycin A2 on isolated nuclei was enhanced over 150-fold by the reduced nicotinamide adenine dinucleotide phosphate (NADPH)-dependent electron transport system of isolated microsomes. The enhancement of bleomycin A2-induced DNA chain breakage by NADPH was also shown at the level of the intact AH66 cells. Furthermore, it was found that the simultaneous administration of bleomycin and NADPH apparently inhibited the growth of Erhlich tumors in mice compared with the administration of bleomycin alone. These results indicate that the action of bleomycin on DNA is stimulated by the microsomal NADPH-dependent electron transport system not only in vitro but also in vivo.

Animals↗
PubMed1979

Elevation of serum lipid peroxide level associated with doxorubicin toxicity and its amelioration by [dl]-alpha-tocopheryl acetate or coenzyme Q10 in mouse (doxorubicin, toxicity, lipid peroxide, tocopherol, coenzyme Q10).

Elevations of serum lipid peroxide levels were demonstrated in mice after an equitoxic dose of doxorubicin. When BDF1 mice were injected with doxorubicin (20 mg/kg body weight, IP), lipid peroxide levels in sera were elevated 1 day after the injection and the levels declined on subsequent days. 5-Fluorouracil (400 mg/kg body weight, IP) never changed the peroxide levels in serum. Furthermore, it was found that the co-administration of [dl]-alpha-tocopheryl acetate or coenzyme Q10 IM strongly inhibited the doxorubicin-induced elevation of lipid peroxides in serum. The effectiveness of [dl]-alpha-tocopheryl acetate or coenzyme Q10 in reducing the lethality of doxorubicin in mice was also confirmed. These results indicate that the measurement of serum 2-thiobarbituric acid-reacting substances provided a useful measurement of lipid peroxide levels, which may be involved in some way with doxorubicin toxicity, and that the administration of antioxidants provide protection against some of the side effects of doxorubicin.

Animals↗