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Biomedical subjects

N Iritani

Publications and source records attributed to N Iritani.

At least 91 records · Page 5Linked to original sources

Effect of corn oil feeding on triglyceride synthesis in the rat.

When rats were fed diets containing 10% corn oil for 2 weeks, alpha-glycerophosphate acyltransferase and diacylglycerol acyltransferase levels were reduced to 75% of that of controls fed a 0.5% corn oil diet, while glucose-6-phosphate dehydrogenase, malic enzyme and acetyl-Coa carboxylase levels were reduced to 28, 33 and 66%, respectively. The incorporation of labeled glycerol or palmitic acid into triglycerides by liver slices was also reduced by corn oil feeding. Therefore, it is suggested that although the major reduction of triglyceride synthesis by linoleic acid feeding is due to fatty acid synthesis, glycerolipid synthesis is also reduced.

Acetyl-CoA Carboxylase↗

Reduction of lipogenic enzymes by shellfish triglycerides in rat liver.

When rats were fed for 2 weeks on 3% fat diets containing 0.5 or 1%corbicula (Corbicula japonica PRIME), clam (Tapes japonica) or oyster (Callocorchina) triglycerides, serum and liver triglyceride levels were significantly lowered. The activities of hepatic glucose-6-phosphate dehydrogenase, malic enzyme and acetyl-CoA carboxylase were markedly reduced in the rats. Cholesterol synthesis by liver slices was also reduced. The results of immunochemical titrations and Ouchterlony double-diffusion analysis indicated that the decreases in the activities of acetyl-CoA carboxylase and glucose-6-phosphate dehydrogenase were due to decreases in the enzyme quantities. The shellfish triglycerides include a high percentage of long chain and polyunsaturated fatty acids, which are common to and characteristic of the three kinds of shellfish. They would be effective components in these observations.

Acetyl-CoA Carboxylase↗

A possible role of Z protein in dietary control of hepatic triacylglycerol synthesis.

The effects of fasting and refeeding on hepatic Z protein were investigated in rats. When [U-14C]palmityl-CoA was added to the liver cytosol fraction from fat-free refed rats, more binding of labeled palmityl-CoA to the Z-protein region was found than in the case of fasted rats. Also the radioactivities in specific precipitations of the palmityl-CoA binding protein with anti-Z immunoglobulin G were higher in the refed rats. The Z protein which stimulated diacylglycerol acyltransferase may be involved in the change of triacylglycerol synthesis in fasted and refed rat livers.

Acyltransferases↗

Effect of feeding the shell fish (Corbicula japonica) on lipid metabolism in the rat.

Rats were maintained for 2 weeks on 3 different diets; a basal diet, one containing 0.1% cholate, and one containing 0.1% cholesterol and 0.1% cholate. Each dietary group was further divided into subgroups whose diet contained 0, 5 or 10% (dry weight) of minced corbicula (Corbicula japonica Prime). Feeding corbicula significantly reduced the increase of cholesterol levels in rats fed the cholesterol diet. Though corbicula contains several sterols, sterols other than cholesterol were almost not absorbed. Serum and liver triglyceride levels were significantly reduced by feeding corbicula meat in all the dietary groups. Activities of glucose-6-phosphate dehydrogenase, malic enzyme and acetyl-CoA carboxylase were also markedly reduced by feeding corbicula. The results suggest that corbicula is a hypolipidemic food.

Animal Feed↗

Influences of oyster or clam feeding on lipid metabolism in rats.

Rats were fed on three kinds of diets for two weeks: (I) basal diet, (II) containing 0.1% cholate and (III) containing 0.1% cholesterol and 0.1% cholate. Each dietary group was further divided into subgroups to whose diet was added 0, 5 or 10% (dry weight) of minced oyster (Callocorchina) or clam (Tapes japonica). The serum and liver cholesterol levels of the rats fed the basal diet were reduced by feeding oyster or clam. The serum and liver triglyceride levels of all dietary groups were lowered markedly by feeding oyster or clam. The activities of glucose-6-phosphate dehydrogenase, malic enzyme and acetyl-CoA carboxylase were markedly reduced in the basal groups fed oyster or clam. These effects were observed in 5 and 10% shellfish feeding. These shellfish may be considered hypolipidemic foods.

Acetyl-CoA Carboxylase↗

Cholesterol metabolism in spontaneously hypertensive rats.

The absorption of radioactive cholesterol tended to be increased, and the catabolism of cholesterol detected by the decay of radioactive cholesterol in the serum after the intraperitoneal injection was delayed in ALR in comparison with normotensive WK rats. The reactive hypercholesterolemia in the ALR which had been selectively bred for a greater hypercholesterolemia was ascribed to the decreased cholesterol catabolism.

Animals↗

Lipid metabolism in spontaneously hypertensive rats (SHR).

Plasma cholesterol was lower in spontaneously hypertensive rats (SHR), while plasma triglyceride and free fatty acid were increased in comparison with control normotensive Wistar-Kyoto (WK) rats. Correspondingly, [1-14C]-acetate incorporation into liver cholesterol was clearly decreased in SHR as compared with WK. As for lipogenic enzyme activities, glucose-6-phosphate dehydrogenase, malic enzyme and acetyl-CoA carboxylase in SHR were respectively decreased, increased and not significantly different, in comparison with WK rats. Liver cholesterol was rather low and cardiac triglyceride was slightly increased in SHR. Aortic cholesterol and triglyceride levels were not significantly different between SHR AND WK rats. Thus, SHR have an abnormality in lipid metabolism, especially in cholesterol synthesis, but the pathological implication of this in hypertension and related vascular lesions is not yet clear.

Acetyl-CoA Carboxylase↗

Effect of fat intake on cholesterol turnover and bile acid formation.

Three groups of male rats were maintained on diets containing different amounts of fat. After one week on such regimens, they were injected intraperitoneally with cholesterol-3H. During the following 28 days, the radioactivity and quantity of fecal cholesterol and its metabolities were determined. The coprostanol excretion was the about same in all groups and the bile acids excretion increased with increasing fat intake; however, compared to the fat-free group, the excretion of the injected cholesterol-3H was greater in the 3% fat group and less in the 10% fat group. Consequently, the specific radioactivity of bile acids was lower in the 10% group than in the others. The half-life of labelled cholesterol was 12.6, 16.0 and 22.2 days for the 3%, 10% fat and fat-free groups, respectively. Rather than a fat-free diet, a low-fat diet of 3% or so, would be of more advantage in eliminating cholesterol by increasing the formation of bile acids to emulsify the fat. In the 10% fat group, however, the enlarged pool size of bile acid probably delayed cholesterol metabolism to bile acids.

Animals↗

Properties of a bicarbonate-stimulated ATPase from rat uterus.

Crude subcellular fractions from rat uterus contain a HCO-3 -stimulated Mg2+ -ATPase with properties analogous to those previously reported for the enzyme in gastric mucosa, pancreas, salivary gland and liver lyosome. Estradiol-17 beta treatment of ovariectomized rats resulted in an increase in uterine mitochondrial (HCO-3 +Mg2+)-ATPase and Mg2+ -ATPase activity. In an early response (105 min) to estradiol-17 beta treatment of ovariectomized rats, the lysosomal enzyme, beta-N-acetylglucosaminidase increased in the nuclear and mitochondrial fractions and decreased in the microsomal and supernatant fractions.

Adenosine Triphosphatases↗

Dietary control of triglyceride and phospholipid synthesis in rat liver slices.

1. The effect of dietary manipulation on the synthesis of triglycerides and phospholipids was investigated by determining the incorporation of labeled long-chain fatty acid or glycerol into these lipids in liver slices derived from normally fed, fasted, and fat-free refed rats. 2. Triglyceride synthesis was affected markedly by the dietary regime of the animal; the lowest rates were measured with fasted rats, and the highest ones with fat-free refed rats. 3. In contrast to triglyceride synthesis, phospholipid synthesis occured at virtually constant rates regardless of the dietary conditions. 4. Addition of large amounts of fatty acid to the incubation mixture resulted in a marked stimulation of triglyceride synthesis, whereas phospholipid synthesis was affected to a much smaller extent. 5. These results indicate that the synthesis of triglycerides and that of phospholipids are controlled independently, and that the availability of fatty acid in the cell contributes to the control of triglyceride synthesis.

Animals↗