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Biomedical subjects

T Sakaguchi

Publications and source records attributed to T Sakaguchi.

At least 361 records · Page 20Linked to original sources
PubMed1979

[A comparison between the effects of angiotensin II and angiotensin III injected into the third cerebral ventricle on vasopressin secretion in conscious rats (author's transl)].

As the greater part of the immunoreactive angiotensin II in cerebrospinal fluid has been suggested to be angiotensin III, a comparison was made between the effects on vasopressin release of angiotensin II and angiotensin III administered into the third cerebral ventricle in conscious male rats. The blood samples were collected 90 seconds after the injection of angiotensin II or angiotensin III by means of decapitation. Plasma vasopressin (microU/ml) extracted and determined by radioimmunoassay were 2.3 +/- 0.8, 6.7 +/- 5.0, 14.0 +/- 2.2, 16.3 +/- 4.3 and 20.7 +/- 2.5 (mean +/- SEM), respectively following the injection of 0, 10, 25, 50 and 100ng of angiotensin II. The increases in plasma vasopressin produced by angiotensin II 25, 50 and 100ng were statistically significant (p less than 0.05). On the other hand, plasma vasopressin following the injection of 22.7 and 45.4ng of angiotensin III, which are equimolar to 25 and 50ng of angiotensin II each, were 14.9 +/- 2.7 and 16.3 +/- 5.6, respectively. No significant difference was found between the effect on plasma vasopressin of angiotensin II and that of angiotensin III at the dose level of 24.3 or 48.6 p. mol. These data indicate that angiotensin III is equipotent to angiotensin II in terms of vasopressin release when administered into the third cerebral ventricle. The possible role of angiotensin III in the brain on vasopressin secretion is discussed.

Angiotensin II↗
PubMed1979

[Establishment of a colony of Japanese white rabbits free from coccidia and their breeding performance (author's transl)].

A colony of rabbits free from coccidia was established in 1974 by weaning young at 25 days of age from dams infected with coccidia. Until now Bordetella, Pasteurella and Psoroptes cuniculi have not been detected either, and neither diarrhea nor death has occurred in weanlings of the colony. However, the mortality of sucklings was significantly high owing to cannibalism and tread by their dams. The weaning rate was effectively improved by use of a large nursing cage (3,100 cm2) and sterilized hay on a stainless steel mesh floor of the nursing cage.

Animals↗
PubMed1979

Uptake of uranium by various cell fractions of Chlorella regularis.

To know what kinds of the cell components of Chlorella regularis are concerned with uranium binding, uptake of uranium by various cell fractions was examined. The uptake value (microgramU/mg starting dry cells) of the hot water-treated cells was almost the same as that of the starting dry Chlorella cells, showing that the cell components extracted with hot water were not so concerned with uranium binding. The cell components extracted with dilute alkali seemed to play an important role in uranium binding, and those extracted with chloroform-methanol seemed to be partly concerned with uranium binding. The cellulose fraction of the cells was scarcely concerned with uranium binding. In the dry cells, 34% of uranium taken up existed in the cell walls. However, in the living cells, 85% existed in the cell walls. The above results showed that the dry or the hot water-treated cells are the most convenient for uranium recovery from the aqueous systems.

Chlorella↗
PubMed1978

Mode of action of 6-cyclohexyl-1-hydroxy-4-methyl-2(1H)-pyridone ethanolamine salt (Hoe 296).

Mode of action studies were made with Hoe 296, a new synthetic antimycotic, mainly in Candida albicans. The specific parameters examined included possible effects on (i) osmotic fragility, (ii) respiration, (iii) uptake and incorporation of radioactive leucine and adenine, and (iv) leakage or efflux of intracellular K+ and other materials. As a result, fungitoxic activity of Hoe 296 appears to be attributed to inhibition of uptake of precursors of macromolecular syntheses from the medium. Uptake and accumulation of leucine in the internal pool of starved cells was more susceptible to the drug than subsequent incorporation into proteins. Hoe 296 was also effective in altering the cell permeability, but greater drug concentrations were required to induce appreciable leakage of cellular constituents, such as 260 nm-absorbing materials, folin-positive substances and potassium ions, from the cells. Osmotic fragility or endogenous respiration was virtually insensitive to the drug. Partial inhibition by relatively high concentrations of Hoe 296 of the respiratory activity of yeast cells or mitochondria therefrom with exogenous substrates can be explained by decreased uptake of the substrates from the medium.

Adenine↗
PubMed1978

[A micro-method developed for prothrombin time assay (author's transl)].

Prothrombin time was measured by a newly developed micro-method using a plastic film available in the market (PARAFILM, American Can. Co.). The comparative study of this micro-method with that of Quick in rats disclosed a good correlation, with correlation coefficient of 0.951, supporting the usefulness of the method for examination of blood coagulability. The new method gave the physiological values of 9.8 sec in rabbits, 12.5 sec in dogs, 13.3 sec in mice, 14.8 sec in cats and 16.0 sec in rats, respectively. Among them, guinea pigs took the longest time of 25.3 sec for the coagulation.

Animals↗