Effect of Feeding Millet (Sorghum vulgarie) Protein at Various Protein Levels on Adrenal Lipids of Rats

A significant increase in adrenal weight, total lipids, cholesterol phospholipids and glycerides (mono-and triglycerides) was observed in rats fed millet at 5, 10 and 15 % protein levels respectively for a period of six weeks as compared to rats fed casein at 10 per cent level. Increases in cholesterol were in both its free and esterified fraction. Adrenal phosphatidyl etha-nolamine was increased in all millet fed rats whereas phosphatidyl choline increased in M–15 % and decreased in M–5 % groups. Other phospholipid fractions viz. monophosphatidyl inositol, lysophosphatidyl ethanolamine, sphingomyeline, phosphatidic acid and polyglycerophosphatide also showed significant alterations in rats fed millet protein as compared to control. Incorporation of acetate–l–¹⁴C into adrenal lipids was lower and that of glucose–U–¹⁴C, palmitate–l–¹⁴C and NaH₂³²PO₄ was higher than the control.     

Effect of Feeding Defatted Millet (Sorghum vulgarie) Flour at Different Protein Levels on Phospholipids of Rat Liver

Effect of feeding defatted millet flour at 5, 10 and 14.5 percent protein levels respectively to rats for 6 weeks has been studied on their liver phospholipids. Feeding of millet at these protein levels significantly increased liver total lipids and total glycerides as compared to control rats fed casein at 10 percent level. Liver phospholipids and phosphatidyl choline were significantly increased in rats fed millet at 10 and 14.5 percent protein levels whereas phosphatidyl ethanolamine was increased in all millet protein fed groups. Incorporation of (counts/liver/100 g body weight) into liver total phospholipids, phosphatidyl choline and phosphatidyl ethanolamine was significantly increased in M–5 and M–15% groups and it was decreased in phosphatidyl choline in rats of M–10% groups as compared to control. The effects of feeding millet on liver phospholipids are due to the quantity as well as quality of the millet protein.     

Effect of Feeding Millet (Sorghum vulgarie) Protein on Growth,Nucleic Acids and Proteins of Liver and Plasma of Rats

Effect of feeding millet (Sorghum vulgarie) at 5, 10 and 15 per cent protein levels respectively for a period of six weeks to rats on their liver DNA, RNA and proteins of liver, its subcellular fractions and plasma has been studied, and results compared with rats fed casein at 10 per cent level. Both liver DNA and RNA of rats fed millet at 5 per cent protein level were significantly increased. Liver proteins (mg/l00 g body weight) of rats fed millet at 5 and 10 per cent protein level were significantly increased and plasma proteins decreased. Incorporation of leucine-I-¹⁴C into both liver and plasma proteins of rats fed millet was significantly higher than the control.     

Effect of Feeding Bengal Gram (Cicer arietinum) at Different Protein Levels on Plasma Lipids of Rats

L-Amino acid ligase catalyzes the formation of an α-peptide bond from unprotected L-amino acids in an ATP-dependent manner, and this enzyme is very useful in efficient peptide production. We performed enzyme purification to obtain a novel L-amino acid ligase from Bacillus subtilis NBRC3134, a microorganism producing peptide-antibiotic rhizocticin. Rhizocticins are dipeptide or tripeptide antibiotics and commonly possess L-arginyl-L-2-amino-5-phosphono-3-cis-pentenoic acid. The purification was carried out by detecting L-arginine hydroxamate synthesis activity, and a target enzyme was finally purified 1,280-fold with 0.8% yield. The corresponding gene was then cloned and designated rizA. rizA was 1,242 bp and coded for 413 amino acid residues. Recombinant RizA was prepared, and it was found that the recombinant RizA synthesized dipeptides whose N-terminus was L-arginine in an ATP-dependent manner. RizA had strict substrate specificity toward L-arginine as the N-terminal substrate; on the other hand, the substrate specificity at the C-terminus was relaxed.     

Turnover Rate of Proteins in Liver Cellular Fractions of Rats Fed High Protein Diets

The effect of high protein intake on the turnover rate of the proteins as well as the protein content of liver cellular fractions has been studied in young rats. When rats fed diets containing high levels of casein, the protein content was increased in various cellular fractions of liver. The incorporation of intraperitoneally injected methionine-S³⁵ into the proteins of these fractions was in the following decreasing order: microsomal, supernatant, mitochondrial and nuclear fraction. The rate of disappearance of radioactivity in various fractions was not so much different from one another, but those of microsomal and supernatant fractions were slightly greater than those of the other fractions. The turnover rates of proteins in all cellular fractions and whole homogenate gradually elevated as the casein level in diets increasing from 25 to 60%. However, the inhancement occurred to a lesser degree than that in the turnover rate of liver proteins with increase in the casein level from zero to 25% which was reported previously.     

Effects of Dietary myo-Inositol,D-chiro-Inositol and L-chiro-Inositol on Hepatic Lipids with Reference to the Hepatic myo-Inositol Status in Rats Fed on 1,1,1-Trichloro-2,2-bis (p-chlorophenyl) Ethane

The effects of dietary 0.2% inositol stereoisomers on the hepatic lipids and myo-inositol (MI) status in rats fed with 1,1,1-trichloro-2,2-bis (p-chlorophenyl) ethane (DDT) were investigated. Dietary MI reduced the hepatic lipids in the rats fed with DDT. Dietary D-chiro-inositol (DCI) and L-chiro-inositol (LCI) both had a promoting effect on the increase in hepatic lipids due to DDT feeding. Dietary MI enhanced the hepatic free MI level and the phosphatidylinositol/phosphatidylcholine ratio, but dietary DCI reduced the level and ratio.     

Myelin-Associated Oligodendrocytic Basic Protein mRNAs Reside at Different Subcellular Locations

The mRNAs for two myelin proteins, myelin basic protein (MBP) and myelin-associated oligodendrocytic basic protein (MOBP)-81A, are uniquely located at sites where myelin sheaths are assembled. Here, we use subcellular fractionation to show that four MOBP mRNAs, like MBP mRNA, are located at sites of myelin sheath assembly, and that three other MOBP mRNAs are located in oligodendrocyte soma. The MOBP-81 protein is found in myelin and in another subcellular fraction, whereas other myelin proteins, including MBP, 2',3'-cyclic nucleotide 3'-phosphodiesterase, and myelin-associated glycoprotein, are largely restricted to myelin. Different MBP mRNAs are generated by alternative splicing. All of them contain an RNA transport sequence (RTS) that directs them to sites in oligodendrocytes, where myelin sheaths are assembled. Consequently, all are enriched in myelin. After fractionation, four MOBP mRNAs, MOBP-71, MOBP-81A, MOBP-99, and MOBP-169 (identified in this study), are enriched in myelin. These mRNAs contain a common exon, exon 8b, which has a nucleotide sequence that is similar to MBP mRNA RTS. This sequence likely directs these mRNAs to sites of myelin sheath assembly. Three other MOBP mRNAs, MOBP-69, MOBP-81B, and MOBP-170, lack this exon. Their subcellular distribution indicates that they are largely retained in oligodendrocyte soma. We conclude that the distribution of MOBPs in oligodendrocytes is strongly influenced by alternative splicing of the corresponding mRNAs.     

Metabolism of Histidine in Growing Rats at Various Dietary Protein Levels

The metabolic fate of the carbon skeleton of l-(U-¹⁴C)-histidine has been investigated in growing rats fed diets containing different percentages of protein calories (0, 5, 10, 15 and 30 PC%) at 410 kcal of metabolizable energy per 100 g diet.

The incorporation of ¹⁴C into body protein at 12 hr after injection of ¹⁴C-histidine was about 70% of the dose in rats fed 0 to 10 PC% diets, though the value was reduced in rats fed higher PC% diets. The expired ¹⁴CO₂ production was depressed in the low protein groups, and it showed an inverse pattern to that of ¹⁴C incorporation into body protein. Urinary excretion of ¹⁴C was about 20% of the dose in all dietary groups. The activities of hepatic histidase, urocanase and histidine-pyruvate aminotransferase were increased in the 30 PC% group.

These results indicate that the metabolic response of histidine to dietary protein changes around 10 PC%, where growth rate and body protein retention reached approximate plateaus.

The nutritional significance of the metabolism of histidine has been discussed and compared with that of leucine, alanine and serine reported previously.     

Fructus Xanthii Attenuates Hepatic Steatosis in Rats Fed on High-Fat Diet

Fructus Xanthii (FX) has been widely used as a traditional herbal medicine for rhinitis, headache, cold, etc. Modern pharmacological studies revealed that FX possesses anti-inflammatory, anti-oxidative, and anti-hyperglycemic properties. The present study was designed to investigate the effects of FX on glucose and insulin tolerance, and hepatic lipid metabolism in rats fed on high-fat diet (HFD). Hepatic steatosis was induced by HFD feeding. Aqueous extraction fractions of FX or vehicle were orally administered by gavage for 6 weeks. Body weight and blood glucose were monitored. Glucose and insulin tolerance test were performed. Liver morphology was visualized by hematoxylin and eosin, and oil red O staining. Expression of liver lipogenic and lipolytic genes was measured by real-time PCR. We showed here that FX improved glucose tolerance and insulin sensitivity in HFD rats. FX significantly decreased the expression of lipogenic genes and increased the expression of lipolytic genes, ameliorated lipid accumulation and decreased the total liver triglyceride (TG) content, and thus attenuated HFD-induced hepatic steatosis. In conclusion, FX improves glucose tolerance and insulin sensitivity, decreases lipogenesis and increases lipid oxidation in the liver of HFD rats, implying a potential application in the treatment of non-alcoholic fatty liver disease.     

Effect of Lipids on the Activity of Calpain in Subcellular Fractions Obtained from the Rat Brain

We studied the effect of lipids on the activity of a neutral cysteine proteinase, calpain, in subcellular fractions obtained from the rat brain. Extraction of nearly 23% of membrane cholesterol from the coarse mitochondrial fraction did not result in modifications of specific activity of calpain in this fraction. Detergents (digitonin or Triton Х-100) used in 0.3% concentration enhanced the activity of calpain in the coarse mitochondrial fraction. Examination of the effects of preparations of different phospholipids on the activity of calpain in the cytoplasm demonstrated that only phosphatidylcholine, but not phosphatidylserine and/or cardiolipin, insignificantly increased the activity of calpain (independently of the size and structure of phospholipid vesicles). We hypothesize that the mechanisms underlying interaction between calpain and lipids are not universal; in native cells and model experiments, they can differ noticeably from each other and are modified depending on the corresponding conditions. Neirofiziologiya/Neurophysiology, Vol. 41, No. 1, pp. 3–9, January–February, 2009.     

Effect of White Wheat Bread Containing Sugar Beet Fiber on Serum Lipids and Hepatic mRNA in Rats Fed on a Cholesterol-Free Diet

We examined the effects of white wheat bread powder (BP) and white wheat bread powder containing sugar beet fiber (BBP) on serum cholesterol. The total cholesterol (?11%, ?16%), HDL-cholesterol (?12%, ?11%), non-HDL-cholesterol (?9%, ?18%) and triacylglycerol (?44%, ?58%) concentrations in the BP and BBP groups, respectively, were significantly different from those in the control group. The fecal excretion of neutral sterols in the BP and BBP groups and of acidic sterols in the BBP group was significantly higher than that in the control group. The hepatic cholesterol 7α-hydroxylase (CYP7A1) mRNA level in the BP and BBP groups was significantly higher than that in the control group. The cecal total short-chain fatty acid concentrations in the BBP group were significantly higher than those in the control group. These results indicate that the observed changes in serum lipid levels in the BP and BBP groups were due to the increased fecal lipid and CYP7A1 mRNA levels.     

Morphological and Biochemical Changes in Myelin Subfractions of Developing Rats Fed Microbial Lipids

Morphological, biochemical, and physicochemical studies of myelin subfractions were undertaken on the progeny of Sprague-Dawley rats fed diets containing lipids either extracted from yeasts grown on n-alkanes or from margarine. Myelin subfractions obtained from pooled brain homogenates of littermates by sucrose density gradient centrifugation at 7, 14, and 21 days postnatally were subjected to electron microscopy, sodium dodecylsulfate polyacrylamide gel electrophoresis and assayed for 2', 3' cyclic nucleotide 3'-phosphohydrolase activity (CNPase; EC 3.1.4.37). Additionally, surface pressure measurements were made of lipid monolayers derived from myelin subfractions, which were subsequently injected with myelin basic proteins. The myelin subfractions of test animals, when compared with those of controls, show an earlier increase in the specific activity of CNPase, the earlier appearance of low-molecular-weight proteins, and an increase in the affinity of basic proteins for lipids derived from the myelin light fraction. This biochemistry suggests the presence of a more mature myelin between 7 and 14 days in the experimental group. The morphological studies, however, do not seem to concur with the biochemical data. The observed changes are discussed in relation to the influence of dietary lipids on myelinogenesis.     

Effects of Corticotropin-(1–24)-Tetracosapeptide on Polyphosphoinositide Metabolism and Protein Phosphorylation in Rabbit Iris Subcellular Fractions

Abstract: Effects of the neuropeptide corticotropin-(1–24) -tetracosapeptide (ACTH) on the endogenous and exogenous phosphorylation of lipids and endogenous phosphorylation of proteins were investigated in microsomes and a 110,000 ×g supernatant fraction [30–50% (NH₄)₂SO₄ precipitate; ASP_30–50] obtained from rabbit iris smooth muscle. Subcellular distribution studies revealed that both of these fractions are enriched in diphosphoinositide (DPI) kinase. The ³²P labeling of lipids and proteins was measured by incubation of the subcellular fractions with [γ-³²P]ATP. The labeled lipids, which consisted of triphosphoinositide (TPI), DPI, and phosphatidic acid (PA) were isolated by TLC. The microsomal and ASP_30–50 fractions were resolved into six and nine labeled phosphoprotein bands, respectively, by sodium dodecyl sulfate polyacrylamide gel electrophoresis. The basal labeling of both lipids and proteins was rapid (30–60 s), and it was dependent on the presence of Mg²⁺ in the incubation medium; in general it was inhibited by high concentrations (>0.2 mM) of Ca²⁺. ACTH stimulated the labeling of TPI and inhibited that of PA in a dose-dependent manner, with maximal effect observed at 50–100 μ of the peptide. ACTH appears to increase TPI labeling by stimulating the DPI kinase. Under the same experimental conditions ACTH (100 μM) inhibited significantly the endogenous phosphorylation of six microsomal phosphoproteins (100K, 84K, 65K, 53K, 48K, and 17K). In the ASP_30–50 fraction, ACTH inhibited the phosphorylation of three phosphoproteins (53K, 48K, and 17K) and stimulated the labeling of six phosphoprotein bands (117K, 100K, 84K, 65K, 42K, and 35K). The effects of ACTH on lipid and protein phosphorylation are probably Ca²⁺-independent; thus the neuropeptide effects were not influenced by either 1 μM EGTA or low concentrations of Ca²⁺ (50 μ.M). We conclude that a relationship may exist between polyphosphoinositide metabolism and protein phosphorylation in the rabbit iris smooth muscle.     

Effect of Fermented Bean Paste on Serum Lipids in Rats Fed a Cholesterol-Free Diet

We examined the effects of fermented bean pastes derived from bean vinegar by-products on serum cholesterol in rats. The rats were fed boiled paste from adzuki (A), kintoki (K), or tebou (T), or fermented paste from adzuki (AP), kintoki (KP), or tebou (TP) for 4 weeks. The serum non-high-density lipoprotein (HDL) cholesterol levels in all the experimental groups, except for A group, were significantly lower than in the control (CN) group. Likewise, the serum triglyceride levels in K and all the fermented bean groups were significantly lower than in the CN group. The levels of hepatic 3-hydroxy-3-methylglutaryl-CoA (HMG-CoA) reductase mRNA in all the experimental groups except for A were significantly lower than in the CN group. These findings indicate that fermented bean pastes also suppress cholesterol synthesis, resulting in a reduced serum cholesterol concentration. These effects might be related not only to the resistant starch but also to the protein or peptide in the fermented bean paste.     

Effect of L-Carnitine Supplementation on Utilisation of Energy and Protein in Broiler Chicken Fed Different Dietary Fat Levels

Effects of a supplementation of 80mg L-carnitine perkg diet were studied in broiler chicken at two dietary levels of fat (4 and 8 %) and different feeding levels (ad libitum in a growth trial, 95 and 85 % of ad libitum in a balance trial). A low-carnitine basal diet adequate in amino acid concentration was used. In the growth trial, each diet was fed to 9 groups of 10 birds each for 16 days from day 5 of live onwards. Growth and feed intake were determined. At the end of the trial, birds were killed and homogenised for subsequent empty body analysis. Accretion of protein and energy was determined using a representative blank group killed at the beginning of the trial. In the balance trial, 8 individual birds were used per treatment. Birds were offered the feed at approximately 85 and 95% of ad libitum intake, which was determined with separate birds for both fat levels. Excreta were quantitatively collected three times daily for 8 consecutive days beginning on day 17 individually for each bird. Supplemented L-carnitine did not significantly affect any response criterion. However, growth and feed conversion tended to be improved by about 5% in the carnitine supplemented diets when fed ad libitum. An interaction between carnitine and fat level occurred with regard to feed conversion, indicating that carnitine had a positive effect at the high fat level, but not at the low fat level. L-carnitine did not positively affect the metabolisability of energy (ME/GE) and the efficiency of energy utilisation (RE/GE or RE/ME). Similarly, no significant carnitine effect was determined with regard to N accretion and the efficiency of utilisation of dietary protein in both trials. It is concluded that endogenous carnitine synthesis is not the limiting factor for energy utilisation in broiler chicken, even at high dietary fat concentration. Occasionally reported positive effects of supplemental carnitine were likewise caused by reasons other than improved energy or protein utilisation. Further studies on amino acid utilisation and catabolism should consider marginal amino acid supply.     

Metabolism of Serine in Growing Rats and Chicks at Various Dietary Protein Levels

The metabolic fate of the carbon skeleton of l-serine-U-¹⁴C has been investigated, in vivo and in vitro, in growing rats and chicks fed the diets with various protein calories percents (PC%) at 410 kcal of metabolizable energy.

The incorporation of ¹⁴C into body protein at 12 hr after the injection of serine-¹⁴C was about 49% of the injected dose in rats fed the 10 or 15 PC % diet, though the value was reduced in rats fed lower and higher protein diets. The ¹⁴CO₂ production was smaller in rats fed the 10 and 15 PC% diet, and it showed an inverse pattern to that of the ¹⁴C incorporation into body protein. Urinary excretion of ¹⁴C was higher in rats fed 10 and higher PC% diets, whose growth rate and net body protein retention were maximum.

In contrast to the case of rats, the incorporation of ¹⁴C into body protein of chicks at 6 hr after the injection was rather reduced in the 15 PC% group. The proportion of ¹⁴C excreted as uric acid was remarkably increased above the 10 PC% group, and about 19% of the injected dose was recovered in the 50 PC% group.

The catabolic rate of serine in the liver slices of rats and chicks was increased by high protein diets.

These results support the concept that the nutritional significance of metabolism of the carbon skeleton of serine in growing rats and chicks is different from each other, especially at high protein diets.     

Metabolism of Glycine and Threonine in Growing Rats at Various Dietary Protein Levels

The metabolic fates of the carbon skeletons of [U-¹⁴C]glycine and l-[U-¹⁴C]threonine were investigated in growing rats fed with diets containing different percentages of protein calories (0, 5, 10, 15, and 30PC%) at 4100 kcal of metabolizable energy per kg of diet.

The incorporation of ¹⁴C into the body protein at 12 hr after the injection of ¹⁴C-glycine was about 58% of the dose in rats fed with the 10 or 15 PC% diet, and the values were reduced in both the lower and higher PC% groups. A considerable amount of ¹⁴C was recovered in the soluble fraction, and it was attributed to labeled glycine and serine in the free amino acid pools of the tissues.

The incorporation of ¹⁴C into the body protein from ¹⁴C-threonine was extremely high in the dietary groups of 0 to 10 PC%, and it decreased in the 30PC% group. Conversely, the expired ¹⁴C0₂ production was much less until the dietary protein level reached at 10PC%, and it increased with higher PC% in the diets. The change in the activity of hepatic threonine dehydratase in rats fed diets with increasing protein levels was similar to that of the expired ¹⁴C0₂ production from ¹⁴C- threonine.

These results indicate that, though the metabolic patterns for glycine and threonine differ from each other, their responses to dietary protein levels change at 10 to 15 PC%, where the growth rate reached its approximate maximum.     

Caseinpbospbopeptides (CPP) in Feces of Rats Fed Casein Diet

The transport-enhancing effects of medium-chain fatty acids (caproic, caprylic, and capric acids) and their acylglycerols (mono-, di-, and triacylglycerols) were investigated by using Caco-2 cell monolayers as a model of the human intestinal epithelium. Penicillin V was used as a model for a hydrophilic bioactive compound. Among the fatty acids and acylglycerols tested, 1,2-dicaproin, monocaprin, monocaprylin, and capric acid sodium salt effectively enhanced the transport rate, whereas other substances enhanced the rate only slightly or not at all. With each of these four substances, the rate of enhancement was proportional to the concentration at low concentrations, but leveled off at high concentrations. The transport-enhancing effects were well correlated with the reduction in surface tension and with a physico-chemical parameter, denoted by the surface energy-lowering coefficient, characterizing the surface activity of a substance.     

Selenium Concentrations in Tissues and Eggs of Growing and Laying Chickens Fed Sodium Selenite at Different Levels

Growing and laying chickens were fed graded levels of selenium in the form of sodium selenite. One day old Norwegian bred broiler chickens and 20 weeks old Norwegian bred White Leghorn chickens were divided into 5 groups each and fed a basal diet supplemented with 0, 0.1, 1.0, 3.0 or 6.0 μg Se/g for 6 and 31 weeks, respectively. At the end of the experiments significantly higher concentrations of selenium were found in the groups fed 1.0, 3.0 and 6.0 μg Se/g diet compared to the control group. Correspondingly higher concentrations of selenium were found in egg samples. The increase in egg yolk selenium was much higher than in egg white. Significant correlations were found between the amounts of selenium added to the ration and the selenium concentrations in liver, kidney, breast muscle, egg white, yolk and homogenized egg. There were no differences in body weight gain and egg production between the groups. A possible positive contribution to animal and human health of selenium supplementation of animals’ diet above the required level is discussed.     

Effect of Dietary Composition on Lipids in Serum and in Liver of Rats Fed a Cystine-excess Diet

The effects of dietary composition on lipids in serum and in liver of rats fed with a cystine- excess diet were investigated.

When starch was used as the carbohydrate source, the addition of excess-cystine caused an increase in serum cholesterol and phospholipids, and hepatomegaly. Phospholipids in serum of rats fed with a cystine-excess diet containing 5% corn oil were higher than those with a cystine-excess diet that was low in corn oil (0.1 %). The addition of konjac mannan and pectin prevented hypercholesterolemia, and the rise in phospholipids in serum was prevented by the addition of konjac mannan.

Liver cholesterol (mg/liver/100 g of body wt.) increased in rats fed with a cystine-excess diet.

The addition of excess cystine to a diet containing sucrose as the carbohydrate source resulted in a marked increase of cholesterol in serum and liver, and a decrease of serum triglycerides.

The replacement of starch by sucrose in the cystine-excess diet increased liver cholesterol.

Lipids, cholesterol, phospholipids and triglycerides in the liver, but not phospholipids, when expressed as mg per g of liver for rats fed with the diets containing sucrose, increased when compared to those for rats fed with the diets containing starch. In contrast, serum triglycerides increased.