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Biomedical subjects

M Sugano

Publications and source records attributed to M Sugano.

At least 91 records · Page 5Linked to original sources
PubMed1998

Effects of dietary shrimp, squid and octopus on serum and liver lipid levels in mice.

The effects of three seafoods, shrimp, squid and octopus, on lipid metabolism were investigated in mice fed on 0.1% and 1.0% cholesterol-supplemented diets in the first experiment. One of each of these seafoods and casein were added to the basal diet at levels of 15% and 5%, respectively, as proteins. Casein served as the sole protein source of the control diet. The serum cholesterol concentration was significantly lower in the mice fed on shrimp and squid in the 0.1% cholesterol diet and on any seafood in the 1.0% cholesterol diet when compared with that in the mice fed on the control diet. The liver cholesterol concentration was significantly lower in all seafood groups given the 0.1% cholesterol diet, and in the squid and octopus groups given the 1.0% cholesterol diet. In the second experiment, the effect of these seafoods on lipid metabolism was compared with that of their defatted products in mice fed on a 0.2% cholesterol diet. Defatting resulted in an increase in the serum cholesterol and triglyceride levels in the shrimp and squid groups. The hepatic cholesterol concentration in all the seafood groups was significantly lower than that in the control group, and defatting did not influence the liver cholesterol concentration. Fecal total steroid excretion was higher in all the seafood groups when compared with that in the control group, and was not modified by the removal of fats. Thus, shrimp, squid and octopus exerted hypolipidemic activity; the serum cholesterol-lowering activity of shrimp and squid was attributed to their lipid fraction, whereas the non-lipid fraction of shrimp, squid and octopus contributed to a reduction of hepatic cholesterol and an increase of fecal steroid excretion.

Animal Nutritional Physiological Phenomena↗
PubMed1998

Effect of dietary fats and sesamin on the lipid metabolism and immune function of Sprague-Dawley rats.

We examined the effect of three dietary fats, safflower oil (SAF) rich in linoleic acid, borage oil (BOR) rich in gamma-linolenic acid, and perilla oil (PER) rich in alpha-linolenic acid, on the lipid metabolism, and chemical mediator and immunoglobulin levels in Sprague-Dawley rats, as well as the dietary effect of sesame-derived antioxidative sesamin. The serum cholesterol, phospholipid, triglyceride, prostaglandin E2 level and splenic leukotriene B4 level were lower in the rats fed on BOR or PER than in those fed on SAF. SES feeding suppressed the expression of the lipid-decreasing effect of BOR, but not in the rats fed on PER. In respect of the fatty acid composition of the liver and spleen, PER feeding gave a lower arachidonic acid level, and higher eicosapentaenoic and docosahexaenoic acid levels than SAF feeding did, while the effect of BOR feeding was marginal. The effect of SES feeding on fatty acid composition was much smaller than that of dietary fats. In respect of immunoglobulin production, PER + SES feeding gave the lowest IgE productivity in the mesenteric lymph node lymphocytes. These results suggest that PER feeding regulated lipid metabolism and exerted an anti-allergic effect by a different mechanism from that with BOR feeding.

Animals↗
PubMed1998

Reciprocal effects of dietary sesamin on ketogenesis and triacylglycerol secretion by the rat liver.

The effects of dietary sesamin (a mixture of sesamin and episesamin, 1:1, w/w) on ketone body production and lipid secretion were studied in isolated perfused liver from rats given sesamin. Feeding sesamin at the dietary level of 0.2% from 14 to 16 d resulted in an enlargement of liver weight. Ketone body production was significantly elevated in the livers perfused with oleic acid in comparison with those perfused without an exogenous-free fatty acid, and sesamin feeding caused a stimulation of ketone body production, especially when exogenous oleic acid was provided. On the other hand, the ratio of beta-hydroxybutyrate to acetoacetate, an index of mitochondrial redox potential, tended to increase in the livers perfused with oleic acid compared with those without fatty acid, thought it was consistently lowered by dietary sesamin. The cumulative secretion of triacylglycerol, but not of cholesterol, by the livers from sesamin-fed rats was decreased markedly, especially when exogenous oleic acid was provided, suggesting an inverse relationship between the rates of ketogenesis and triacylglycerol secretion. These results suggest that dietary sesamin exerts its hypotriglyceridemic effect at least in part through an enhanced metabolism of exogenous-free fatty acid to oxidation at the expense of esterification in rat liver.

3-Hydroxybutyric Acid↗
PubMed1997

Effect of dietary omega-3 eicosapentaenoic acid supplements on cholesteryl ester transfer from HDL in cholesterol-fed rabbits.

We investigated the reactivities of cholesteryl ester transfer protein (CETP) in Japanese white rabbits fed either a low-cholesterol diet containing 0.1% cholesterol (Control group) or a diet containing 0.1% cholesterol plus 17.5% omega-3 eicosapentaenoic acid (omega-3 20:5, EPA) of 4.5% (w/w) total lipid (EPA group) for 6 weeks. The plasma total and LDL cholesterol levels and aortic cholesterol content were all significantly higher in the EPA group than in the control group. The aortic cholesterol content significantly correlated with LDL cholesterol (r = 0.81). HDL cholesterol levels tended to be lower in the EPA group compared with control group, which was not statistically significant. The plasma VLDL cholesterol levels did not differ significantly between the groups. In addition, no significant differences were observed in the plasma CETP activity or lecithin:cholesterol acyltransferase (LCAT) activity between the groups. However, the cholesteryl ester (CE) mass transfer from fractionated HDL in the EPA group to excess VLDL and/or LDL as acceptors by purified CETP increased significantly compared with the control group, even if the acceptors were fractionated from either the EPA or the control group. Fatty acid analyses of CE showed that the omega-3 18:3, 20:4 or omega-3 20:5 fatty acid acyl groups in CE of HDL were significantly more transferred to apo B-containing lipoproteins compared with the 14:0,16:0, 18:0, 18:1 or 18:2 fatty acid acyl groups in CE of HDL during the incubation period. The amount of CE in HDL containing omega-3 18:3 and omega-3 20:5 fatty acid acyl groups was greater, while the amount of CE containing 18:2 fatty acid acyl groups was smaller in the EPA group than in the control group. These results show that although CETP itself did not change, the transfer of CE in HDL to apo B-containing lipoproteins by CETP increased in the rabbits fed a diet containing EPA as the HDL is modified by the diet, which may partly explain why atherogenicity was thus found to progress in the rabbits fed a cholesterol plus EPA diet.

Animals↗
PubMed1997

Increase in degranulation of mucosal mast cells in rats sensitized with milk whey protein hydrolysates compared with native proteins.

The allergenicity of two types of whey protein hydrolysates-bacterial protease hydrolysed whey protein (BHW) with a molecular mass less than 3500 and trypsin hydrolysed whey protein (THW) with a molecular mass less than 6500-was compared with that of whey protein concentrate (WPC) or beta-lactoglobulin (beta-LG) in vivo by their ability to release rat chymase II (RChyII), an indicator of mucosal mast cell degranulation in the intestine. Antigen-specific reaginic activity and immunoglobulin (Ig)G in serum were markedly lower in rats primed with BHW than in those with WPC or beta-LG, although these were not lowered in THW-primed rats. In contrast, rats primed with either hydrolysate and subsequently orally challenged with the primed antigen increased the release of RChyII to a greater extent than did rats primed and challenged with the native proteins. The extent of the release was primarily attributed to the nature of primed rather than challenged antigen. These results indicate that determination of circulatory RChyII is a sensitive in vivo method to evaluate the allergenicity of milk protein hydrolysates. The improper hydrolysis of dietary protein may enhance allergic reactions.

Animals↗
PubMed1997

Linoleic and alpha-linolenic acids differently modify the effects of elaidic acid on polyunsaturated fatty acid metabolism and some immune indices in rats.

To explore whether the metabolic responses to trans, compared with cis, fatty acids depend on the source of dietary polyunsaturated fatty acids (PUFA), male Sprague-Dawley rats, 5 weeks old, were fed on diets containing 30 g oleic (cis) or elaidic (trans) acids/kg in combination with either 70 g perilla oil (alpha-linolenic acid) or safflowerseed oil (linoleic acid)/kg for 3 weeks in separate experiments. The dietary fats were adjusted to have the same level of total PUFA. The dietary manipulation did not influence the growth indices, but spleen weight was greater when the dietary PUFA source was perilla oil. The incorporation of trans fatty acid into liver phosphatidylcholine, phosphatidylethanolamine, phosphatidylinositol and phosphatidylserine and adipose tissue lipids, particularly phospholipids, was significantly higher when rats were fed on safflowerseed oil compared with perilla oil. However, only limited differences were observed in the effects of cis and trans fatty acids on the proportions of PUFA in liver phospholipids. Splenic production of prostaglandin E2 was reduced by trans fatty acid when safflowerseed oil was the PUFA source, but no trans effect was observed on leukotriene C4 production. Dietary PUFA significantly influenced the concentration of plasma immunoglobulins (Ig) but the effect of geometry was only seen in IgG which was increased by trans acid. Dietary trans fatty acid increased the CD4+:CD8+ T-lymphocyte ratio in the spleen, reflecting a decreasing trend of the proportion of CD8+, when combined with perilla oil. These observations indicate that the type of PUFA simultaneously ingested specifically influences the effect that trans acid exerts on PUFA metabolism, eicosanoid production and some immune indices.

Animals↗
PubMed1997

Rice bran oil and cholesterol metabolism.

A range of human and animal studies have shown that rice bran oil (RBO) is an edible oil of preference for improving serum cholesterol levels and lipoprotein profiles with similarity to the more commonly used vegetable oils such as corn oil and safflower oil. Of particular interest is the observation that blending RBO with safflower oil at a definite proportion (7:3, wt/wt) magnifies the hypocholesterolemic efficacy, compared with the effect of each oil alone. Although the mechanism underlying this effect is not apparent at present, the blending may have a practical significance. The blending effect was reproduced in rats fed a cholesterol-enriched diet, and there was also a decrease in liver cholesterol. The occurrence of peculiar components such as gamma-oryzanol and tocotrienols could be responsible for the hypocholesterolemic effect of RBO.

Animals↗
PubMed1997

Dietary fibers modulate indices of intestinal immune function in rats.

To explore the immunological roles of dietary fiber, male 4-wk-old Sprague-Dawley rats were fed for 2 wk cellulose (water-insoluble), konjak mannan (water-soluble), pectin (water-soluble) or chitosan (acid-soluble) at 5 g/100 g diet. Serum IgE concentrations in rats fed konjak mannan, pectin and chitosan were significantly lower than in those fed cellulose (mean +/- SEM: 5.0 +/- 1.1, 3.6 +/- 1.3, 3.0 +/- 1.2 and 9.6 +/- 1.9 microg/L, respectively). Rats fed pectin had significantly higher serum IgA and IgG concentrations (358 +/- 38 and 424 +/- 36 mg/L for IgA and IgG, respectively) than those fed cellulose (240 +/- 31 and 337 +/- 25 mg/L) or chitosan (176 +/- 22 and 379 +/- 23 mg/L), while the IgM concentration did not differ among the groups. Concentrations of IgA, IgG and IgM in mesenteric lymph node (MLN) lymphocytes generally were greater, while IgE concentration was lower, in rats fed pectin and chitosan than in those fed cellulose. The proportion of CD4+ T-cells in MLN lymphocytes was also dietary fiber-dependent, and the CD4+/CD8+ ratio was significantly higher in the pectin fed group than in all other groups. Under certain experimental conditions, MLN lymphocytes from rats fed pectin had markedly greater interferon-gamma concentration than cells from other groups, while the effect on tumor necrosis factor-alpha concentration was less marked. Thus, dietary fiber may have an immunoregulatory effect on the intestinal immune system of rats.

Animals↗
PubMed1997

Effect of unsaturated fatty acids and alpha-tocopherol on immunoglobulin levels in culture medium of rat mesenteric lymph node and spleen lymphocytes.

Mesenteric lymph node (MLN) and spleen lymphocytes of Sprague-Dawley rats were cultured with 1 mM unsaturated fatty acids (UFAs) with or without 100 microM alpha-tocopherol (Toc), and the immunoglobulin content and thiobarbituric acid (TBA) value of the culture media were measured to clarify the relationship between lipid peroxidation and the IgE level in the culture medium. The increase in the IgE content and TBA value induced by UFAs was alleviated in the presence of Toc in both lymphocytes, and was correlated well with their oxidation rates in most cases. Gamma-linolenic acid enhanced the IgE level much more than would be expected from its oxidation rate in both lymphocytes, and linoleic acid showed similarly high activity only in splenocytes. These results suggest that lipid peroxidation is partly responsible for the enhancement of IgE level induced by UFAs.

Animals↗
PubMed1997

Effect of tea polyphenols on histamine release from rat basophilic leukemia (RBL-2H3) cells: the structure-inhibitory activity relationship.

We studied the effect of tea polyphenols on histamine release from rat basophilic leukemia (RBL-2H3) cells. Among tea polyphenols, (-)- epigallocatechin gallate (EGCG) most strongly and dose-dependently inhibited histamine release from cells stimulated with a calcium ionophore, A23187. (-)-Epigallocatechin (EGC) and (-)-epicatechin gallate (ECG) with a triphenol residue moderately inhibited histamine release, whereas diphenolic (+)-catechin (C) and (-)-epicatechin (EC) did not. The magnitude of the inhibitory effect was in the order EGCG > ECG > EGC. Among simple polyphenols, the triphenol compounds, pyrogallol (PG) and gallic acid (GA) exerted inhibitory activity, but the diphenols, pyrocatechol, hydroquinone, and resorcinol did not. In addition, the mixture of PG and GA inhibited histamine release as strongly as EGCG with two triphenol residues. Similarly, they inhibited histamine release induced by IgE-antigen complex stimulation more efficiently than that induced by A23187 stimulation. EGCG did not inhibit the increase of intracellular Ca2+ in RBL-2H3 cells stimulated with A23187 or IgE antigen. These results indicate that the triphenol structure plays an important role in the inhibitory activity of tea polyphenols. Their activity seemed to be exerted through the metabolic events occurring after the elevation of intracellular Ca2+ concentration.

Animals↗
PubMed1997

Molecular mechanism of angiotensin II type I and type II receptors in cardiac hypertrophy of spontaneously hypertensive rats.

We administered angiotensin (Ang) II receptor type 1 (AT1) blockade (losartan; 10 or 40 mg/kg per day), type II receptor (AT2) blockades (PD123319; 100 mg/kg per day), or angiotensin-converting enzyme (ACE) inhibitor (enalapril; 30 mg/kg per day) to spontaneously hypertensive rats (SHR) from 10 to 20 weeks of age. At the end of the treatment, high doses of losartan and enalapril significantly reduced the arterial systolic blood pressure compared with the untreated SHR to the level of WKY rats. But low doses of losartan and PD123319 were without effect. High doses of losartan and enalapril also significantly reduced both the left ventricular (LV) weight and the ratio of LV to body weight compared with the untreated SHR, which were still larger than that of WKY rats. However, the collagen concentration of SHR treated with high doses of losartan or enalapril was completely reduced to the level of WKY rats. Using reverse transcription polymerase chain reaction, we examined the mRNA expression for ACE, AT1, and AT2 in experimental animals. The enhanced AT1 mRNA expression was significantly decreased in the SHR treated with a high dose of losartan or PD123319 compared with the untreated SHR. The level of ACE mRNA was also decreased in the SHR treated with a high dose of losartan or enalapril. The level of AT2 mRNA was not significantly different between the Wistar-Kyoto rats and the SHR; however, this expression was decreased significantly after the treatment with a high dose of losartan or PD123319. These results indicate that AT1 receptor and ACE, but not AT2 receptor, play a crucial role in the remodeling of matrix tissue but a smaller role in the development of the hypertrophy of LV myocyte in SHR and that the LV/body weight changes do not fully account for the complete suppression of hypertension.

Angiotensin Receptor Antagonists↗
PubMed1997

In vitro and ex vivo anti-human immunodeficiency virus (HIV) activities of a new water-soluble HIV protease inhibitor, R-87366, containing (2S,3S)-3-amino-2-hydroxy-4-phenylbutanoic acid.

In a series of compounds containing (2S,3S)-3-amino-2-hydroxy-4-phenylbutanoic acid (AHPBA), a transitionstate mimetic, R-87366:(2S,3S)-3-[N-(quinoxaline-2-carbonyl)-L-asparaginyl]amino- 2-hydroxy-4-phenylbutanoyl-L-proline tert-butylamide, was found to be a potent human immunodeficiency virus protease inhibitor (Ki value was 11 nM) and anti-HIV agent (IC90 value was 0.5 microM for HIV-1IIIB acutely infected cells) with moderate water-solubility (4.2 mg/ml at 25 degrees C). The compound was also active in chronically infected Molt-4/HIV-1IIIB cells, and inhibited the proteolytic processing of p55 into p17, suggesting that its anti-HIV activity was derived from HIV protease inhibition. The compound showed more potent activity (IC90 value was 0.03-0.25 microM) against clinical isolates of HIV in 5 out of 6 patients examined with varying clinical status in an ex vivo assay. One isolate, however, from the sixth patient, was less sensitive to R-87366 (IC90 value was 0.5 microM). In experiments with this strain, R-87366 showed comparatively low efficacy in acutely infected peripheral blood mononuclear cell (PBMC). This result suggests that the diversity of sensitivity shown in the ex vivo assay could be caused by the viral property itself. As a result of the determination of nucleic acid sequences in the clinical isolates, some amino acids were found to be substituted in the protease region, in contrast to the HIV-1 clade B consensus sequence, and some of them have been reported to contribute to the susceptibility of HIV protease inhibitors.

Amino Acid Sequence↗
PubMed1997

Effect of vegetable extracts on immunoglobulin production by mesenteric lymph node lymphocytes of Sprague-Dawley rats.

To clarify the immunoglobulin production-regulating activity of vegetable extracts, mesenteric lymph node lymphocytes of Sprague-Dawley rats were cultured in the presence of 25 different vegetable extracts. The immunoglobulin content in the culture medium determined by ELISA indicated that the lily family (Liliaceae) vegetables most strongly enhanced the production of IgA and IgG, whereas they suppressed IgE production.

Animals↗
PubMed1997

Stimulating effect of xanthene dyes on immunoglobulin produced in vitro by rat spleen lymphocytes.

The effects of food additives on immunoglobulin produced in rat splenic lymphocytes were examined. The xanthene dye, Rose Bengal, enhanced IgE production, while inhibiting the production of IgG and IgM, at 50 microM. Among the xanthene dyes, Rose Bengal having 4 iodine and 4 chlorine atoms exerted the highest Ig production-regulating activity in splenocytes, and dihalogenated fluorescein, a diiodo compound, exerted similar activity, while the dichloro and dibromo compounds did not. These results suggest that halogen atoms, especially the iodine atom, in xanthene dyes play an important role in regulation of Ig production.

Animals↗
PubMed1997

Effects of dietary sesaminol and sesamin on eicosanoid production and immunoglobulin level in rats given ethanol.

The effects of sesaminol and sesamin on the ethanol-induced modulation of immune indices related to food allergy were examined in rats given a low (10%)-casein diet. Chronic ethanol drinking, at the dietary level of 23% (w/w), significantly increased the plasma IgA and IgM concentrations, irrespective of the presence of 0.1% and 0.2% sesaminol, but the effects disappeared with 0.2% sesamin. A significant IgG-elevating effect of these lignans was also found. In contrast, the concentration of plasma IgE was not influenced by the dietary manipulation. Although ethanol drinking did not influence splenic leukotriene B4 production, sesaminol tended to decrease it dose dependently, while sesamin increased the plasma prostaglandin E2 concentration. These results suggest that sesaminol and sesamin seems to have a diverse effect on the plasma levels of immunoglobulins and eicosanoids.

Analysis of Variance↗
PubMed1997

Use of highly purified porcine FSH preparation for superovulation in Japanese black cattle.

Fifty cattle were divided into 3 groups (I, II, III) according to FSH-R dosage used to induce superovulation between days 9 and 11 of the estrous cycle. Ova/embryo recovery rate did not differ significantly between groups I and II administered total dosages of 16 and 24 mg, respectively. However, the average number of recovered ova/embryos and transferable embryos was significantly lower in group III (administered a total dosage of 30 mg) (P < 0.05) than groups I and II. These results suggest that intramuscular administration of 16 mg FSH-R over 3 days is sufficient for inducing superovulation in Japanese Black cattle.

Animals↗
PubMed1997

[Distribution of the apolipoprotein-E and -E-complexes in lipoproteins of human serum with the apolipoprotein-E4/E3 phenotype].

Distribution of apolipoprotein(apo) E4 and E3 in lipoproteins of serum with apoE4/E3 phenotype was analyzed. ApoE was eluted in two major peaks by gel chromatography; peak 1 and 2 corresponding to very- and intermediate-low density lipoprotein (VLDL + IDL) and high density lipoprotein2 (HDL2), respectively. ApoE in peak 1 (VLDL + IDL) consisted of monomers of 34 kDa, complexes with a high molecular weight (apoEs) of 100 kDa and with a small amount of apoE-AII complexes weighing 43 kDa. In contrast, apoE in peak 2 (HDL2) was composed mainly of apoE-AII complexes and apoEs complexes, and a small amount of monomers. Both apoE3 and E4 isoforms were detected in these peaks; E4 was more predominant in peak 1 while E3 was more predominant in peak 2. These findings suggest that different distributions of apoE3 and E4 in lipoprotein particles.

Apolipoprotein A-II↗