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F Masugi

Publications and source records attributed to F Masugi.

53 records · Page 3Linked to original sources
PubMed1979

Transfer of alpha-tocopherol from plasma to erythrocytes in vitamin E-deficient rats.

The transfer of alpha-tocopherol from plasma to erythrocytes was examined using labeled alpha-tocopherol in vitamin E-deficient rats and at the same time the appearance of resistance to dialuric acid-induced hemolysis in the erythrocytes was observed. It was noticed that the transfer took place in two sequential steps. The second step seemed to correlate the appearance of resistance to dialuric acid-induced hemolysis, d-alpha and d,l-alpha-Tocopherol were compared under the same in vitro experimental conditions and no difference between them was observed in the effect on the recovery of antihemolytic activity. The difference in physiological activity between d-alpha- and d,l-alpha-tocopherol may exist other than in the transfer step. The coexistence of alpha-tocopherol and alpha-tocopherol quinone did not show any inhibiton for transfer of alpha-tocopherol from plasma to erythrocytes in vitamin E-deficient rats.

Animals↗
PubMed1978

Effect of d,l-alpha-tocopheryl esters on vitamin E-deficient rats.

The data in our previous paper demonstrated that some alpha-tocopheryl esters administered orally were absorbed in their unchanged form through the lymph, while some other esters were absorbed after being hydrolyzed individually to different degrees. The hydrolysis during absorption seems to be related to the structure of the ester group of alpha-tocopherol at the 6-position. The purpose of this work is to study the metabolism and biological effect of tocopherol esters in vitamin E-deficient rats. Three esters were used on the basis of their behavior during absorption through the lymph, as follows; alpha-tocopheryl acetate (an easily hydrolyzable ester), the nicotinate (a moderately hydrolyzable one) and the pivalate (a scarcely hydrolyzable one). The easily hydrolyzable esters will suffer the same metabolic fate through absorption as alpha-tocopherol. The moderately and scarcely hydrolyzable ones have a tendency to show different physiological effects from alpha-tocopherol due to absorption of the unchanged ester. The effect of these esters on the microsomal enzymes in the liver such as cytochrome P-450, cytochrome b5, aniline and hexobarbital difference spectra and NADPH-dependent cytochrome c reductase was determined. It was shown that the pivalate inhibited the release of NADPH-dependent cytochrome c reductase activity to supernatant in spite of low distribution in the 105,000 X g sediment. The result suggests that the pivalate as a model compound may be interesting to examine for its membrane stabilizing effect of alpha-tocopherol.

Acetates↗
PubMed1976

Effect of vitamin E deficiency on the level of superoxide dismutase, glutathione peroxidase, catalase and lipid peroxide in rat liver.

The activities of superoxide dismutase, glutathione peroxidase, catalase and xanthine oxidase were simultaneously studied in vitamin-E deficient and -supplemented rat liver and also measured the lipid peroxide content in liver. The lipid peroxide content of vitamin E-deficient rat liver, estimated by thiobarbituric acid, increased as compared with that of vitamin E-supplemented rat liver. No marked changes of activities of superoxide dismutase, glutathione peroxidase and catalase were observed, but the activity of xanthine oxidase which is strong superoxide generator increased in vitamin E-deficient rat liver. These results suggest that vitamin E prevents the accumulation of lipid peroxide, but not controls the level of peroxide scavenging system such as superoxide dismutase, glutathione peroxidase and catalase.

Animals↗
PubMedDate not supplied

Role of acetyl glyceryl ether phosphorylcholine in blood pressure regulation in rats.

The role of an endogenously occurring acetyl glyceryl ether phosphorylcholine (AGEPC) in blood pressure regulation was studied with an AGEPC antagonist in rats with hypertension of various etiologies. The hypotensive activity of an intravenously injected AGEPC was competitively suppressed by the intravenous infusion of 3-(N-n-octadecylcarbamoyloxy)-2-methoxypropyl-2-thiazolioethylphospha te (CV-3988) and was dose-dependent. The CV-3988 was infused intravenously into one- and two-kidney, one clip hypertensive, deoxycorticosterone-salt hypertensive, adrenal regeneration hypertensive, spontaneously hypertensive, and normotensive control rats. The increase in blood pressure caused by CV-3988 infusion in spontaneously hypertensive and normotensive control rats was significant (p less than 0.01 and p less than 0.001, respectively, at 60 min) compared with that caused by vehicle infusion. The increase was not seen in rats with secondary hypertension. In rats with two-kidney, one clip hypertension, the initial rapid decrease in blood pressure seen after unclipping was significantly (p less than 0.05) inhibited by CV-3988 infusion as compared with that by vehicle infusion. These results suggest that endogenous AGEPC may participate in the blood pressure regulation and pathophysiology of some forms of hypertension in rats.

Angiotensin II↗
PubMedDate not supplied

Dietary salt, blood pressure and circulating levels of 1-O-hexadecyl-2-acetyl-sn-glycero-3-phosphocholine in patients with essential hypertension.

The effects of dietary salt on circulating levels of 1-O-hexadecyl-2-acetyl-sn-glycero-3-phosphocholine (C16 PAF) in patients with essential hypertension were studied by gas chromatography/mass spectrometry with negative ion chemical ionization. Circulating levels of C16 PAF in patients with essential hypertension (18.1 +/- 5.3 pg/ml, n = 16) were not changed compared with those in normotensive subjects (17.2 +/- 7.2 pg/ml, n = 14). Although changes in circulating levels of C16 PAF were small with changes in dietary salt, net changes in circulating C16 PAF levels significantly and positively correlated with net changes in mean arterial blood pressure (r = 0.47, P less than 0.05). Changes in C16 PAF levels also correlated with changes in creatinine clearance (r = 0.55, P less than 0.05). However, changes in C16 PAF levels did not correlate with changes in plasma sodium concentration, plasma chloride concentration and plasma volume. These results indicate that C16 PAF plays an antihypertensive role and this may be reflected as small changes in circulating levels of C16 PAF.

Adult↗