Nutritional utilization by rats of chickpea (Cicer arietinum) meal and its isolated globulin proteins is poorer than that of defatted soybean or lactalbumin

The effects on performance, digestibility, N utilization and plasma amino acid concentrations of dietary chickpea (Cicer arietinum, var. Kabuli) seed meal, globulin proteins or buffer-insoluble residue [starch + non-starch polysaccharides (NSP) + lignin] were studied in growing rats. Chickpea meal, defatted soybean meal, chickpea globulins and lactalbumin were each incorporated into diets as the sole source of dietary protein (100 g/kg). In addition, chickpea insoluble residue was included in a control diet in the same proportion found in the chickpea meal. Rats were killed while under halothane anesthesia after 10 d of consuming the diets, and ileal contents were washed out and freeze-dried for digestibility measurements. Weight gains and gain:feed ratios of rats fed chickpea diets for 10 d did not differ from those of rats fed defatted soybean but were significantly lower than those of rats given the control (lactalbumin) diet. However, ileal and fecal N digestibilities and N retention by rats fed the chickpea diet were significantly lower than those obtained with the lactalbumin or soybean diet. The inclusion of both chickpea meal or its globulin proteins in the diet significantly increased the amount of N excreted, primarily as urea, through the urine. However, although ileal N digestibility values for chickpea meal were significantly lower, those for its constituent globulins did not differ from control values. Urea levels in plasma in rats fed diets containing chickpea meal, globulins or soybean meal were significantly higher than in those fed lactalbumin. Furthermore, the concentrations of glycine, phenylalanine, histidine, arginine and ornithine in the plasma of rats fed chickpea meal, its globulins or defatted soybean were significantly higher, whereas those of threonine, leucine, lysine and tryptophan were significantly lower than lactalbumin-fed controls. The chickpea insoluble residue had no adverse effects on performance or N utilization by rats. We conclude that the low nutritional value of chickpea meal is likely to be due mainly to adverse effects of its globulin proteins on growth and N metabolism rather than to the action of any known antinutritional factor present in the diet.     

Helium-oxygen improves Clinical Asthma Scores in children with acute bronchiolitis

Sprague-Dawley rats (n = 32) were fed diets without fiber (control) or containing 1 or 5% chicory extract or 5% inulin for 4 wk; 0.2% cholesterol was added to all diets. Rats fed chicory extract and inulin diets had significantly higher serum high density lipoprotein (HDL) cholesterol and generally lower low density lipoprotein (LDL) cholesterol concentrations, thus significantly greater ratios of HDL/LDL cholesterol compared with the controls (P < 0.05). The serum apolipoprotein B/apolipoprotein A-1 ratio was significantly lower in rats fed diets containing chicory extract or inulin than that in rats fed fiber-free diets, due to significant reductions in apolipoprotein B concentration (P < 0.05). Greater liver lipid and triglyceride concentrations were observed in rats fed chicory extract or inulin diets compared with the controls (P < 0.05). However, liver phospholipid and cholesterol concentrations were not significantly different among groups (P > 0.05). Addition of 5% inulin to the diet resulted in greater cecal weight, whereas both 5% chicory extract and 5% inulin resulted in greater cecal propionic acid concentration compared with the controls (P < 0.05). Rats fed chicory extract and inulin had significantly greater fecal lipid, cholesterol and bile acid excretions than those fed fiber-free diets (P < 0.05). The results of this study suggest that the improved lipid metabolism observed in rats fed chicory extract (mainly inulin component) may be caused by an alteration in the absorption and/or synthesis of cholesterol, which might result from the changes in cecal fermentation, and by an increase in the fecal excretion of lipid, cholesterol and bile acid.     

Effects of spinach leaf protein concentrate on the serum cholesterol and amino acid concentrations in rats fed a cholesterol-free diet

The effects of spinach leaf protein concentrate (SPPC) on serum and liver lipid concentrations and on serum free amino acid concentrations were examined in rats fed a cholesterol-free diet containing 2 and 10% fats. The serum total cholesterol, triacylglycerol and phospholipid concentrations in the rats fed an SPPC diet containing 2% corn oil were significantly lower than those of the rats fed a corresponding casein diet. When 10% corn oil or lard was used, the serum cholesterol-lowering effect of the SPPC became insignificant, but the serum and liver triacylglycerol concentrations were kept at significantly lower levels. Both the amounts of fecal neutral steroids and bile acids were significantly higher in the rats fed the SPPC than those of the casein-fed rats. The concentrations of serum threonine, serine, glutamine, glycine, cystine, and isoleucine were significantly higher in the rats fed the SPPC diet containing 2% corn oil compared with those of the control rats, but when the dietary fat was raised to 10%, only glycine showed a higher serum concentration. These results indicate that the SPPC has a stronger cholesterol-lowering effect at a lower dietary fat level, 2%, and the activity is partly due to the inhibition of intestinal absorption of cholesterol and bile acid, and partly due to an increase in the concentration of some of the serum amino acids.     

Hypolipidemic effect of hemicellulose component of coconut fiber

The neutral detergent fiber (NDF) isolated from coconut kernel was digested with cellulase and hemicellulase and the residual fiber rich in hemicellulose (without cellulose) and cellulose (with out hemicellulose) were fed to rats and compared with a fiber free group. The results indicate that hemicellulose rich fiber showed decreased concentration of total cholesterol, LDL + VLDL cholesterol and increased HDL cholesterol, while cellulose rich fiber showed no significant alteration. There was increased HMG CoA reductase activity and increased incorporation of labeled acetate into free cholesterol. Rats fed hemicellulose rich coconut fiber produced lower concentration of triglycerides and phospholipids and lower release of lipoproteins into circulation. There was increased concentration of hepatic bile acids and increased excretion of faecal sterols and bile acids. These results indicate that the hemicellulose component of coconut fiber was responsible for the observed hypolipidemic effect.     

Transcriptional activation of the human c-myc gene by simian virus 40 large T antigen without binding to p53 and RB proteins in the transient expression system

Male adult Wistar rats were randomly divided into four groups in a 2 x 2 factorial design and were fed diets containing cooked-stored polished rice (CSPR), with and without 0.7 g/100 g of Nebacitin [bacitracinneomycin sulfate (2:1, wt/wt)] and with and without 1 g cholesterol/100 g diet. The CSPR diet contained 1.87 g resistant starch/100 g. After 4 wk, arterial blood and liver were collected. Feces were collected during the last 7 d. Rats fed the diet with Nebacitin and cholesterol had higher serum total cholesterol than the rats fed diets without cholesterol. Serum triglyceride concentration was greater in rats fed Nebacitin, regardless of dietary cholesterol concentration. Rats fed the diet with Nebacitin and cholesterol had higher serum LDL cholesterol concentration and liver total cholesterol concentration than rats fed the other three diets. Rats fed the CSPR diet with Nebacitin both with and without cholesterol had a higher fecal resistant starch concentration and excretion and lower serum short-chain fatty acid concentration than rats fed the diets without Nabacitin. Hepatic cholesterol concentration was greater in rats fed Nebacitin only when the diet also contained cholesterol. Therefore, dietary Nebacitin alters lipid metabolism in rats, and some effects are most pronounced in those also fed cholesterol.     

Early detection of avascular necrosis of the femoral head by MRI

Male, Sprague-Dawley rats were treated with 0, 1, 10, 50, 100 ppm chlordecone (Cd) mixed in calcium-sufficient (Ca-S) or calcium-deficient (Ca-D) diet for 15 days. A significant decrease in body weight gain was observed in 100 ppm of Cd-treated rats. Cholinesterase (ChE) activity was significantly decreased in serum of Ca-D rats. Chlordecone did not alter serum ChE activity in both Ca-S and Ca-D rats. However, Cd decreases serum triglycerides, low density lipoproteins (LDL) and cholesterol in both Ca-S and Ca-D rats. Rats fed with Ca-S or Ca-D diet exhibited differential sensitivity to Cd-toxicity. Decreased levels of serum triglycerides, LDL and cholesterol suggest that Cd might interfere in lipid metabolism.     

Thyroid hormone is required for dietary fish oil to induce hypersecretion of biliary cholesterol in the rat

In the rat, both fish oil diet and thyroid hormone replacement are reported to augment bile cholesterol secretion out of proportion to bile flow or secretion of other bile lipids. We sought common mechanisms for these effects and evaluated the role of phospholipid fatty acid composition in the process. Methimazole-treated hypothyroid rats were fed low-fat chow or chow supplemented with 10% corn oil or fish oil, and were studied before and after thyroid hormone treatment. Serum, hepatic, and bile lipids were measured, phospholipid fatty acid composition determined, and hepatic 3-hydroxy-3-methylglutaryl CoA reductase activity assayed. Fish oil diet stimulated cholesterol secretion into bile only after thyroid hormone was given, and this action was synergistic with that of thyroid hormone. Reduced serum cholesterol in fish oil-treated rats was associated with increased biliary cholesterol secretion and diminished hepatic cholesterol content. This suggests that augmented biliary cholesterol secretion may contribute to the fish oil-induced reduction of serum cholesterol. No definite relationship between hepatic or biliary phospholipid fatty acid composition and biliary secretion was apparent, although high bile cholesterol secretion was associated with a low percentage of hepatic and bile phospholipid linoleic acid.     

Development of atherosclerosis in alloxan diabetic rats

Rats with alloxan-induced diabetes developed severe atherosclerotic lesions when they were maintained on a 0.25% cholesterol diet for one year. The atheromatous changes developed at the aortic arch, appeared as early as 3 months after the start of the experiment, and increased thereafter. The diabetic rats also developed atherosclerosis when they were fed standard rat chow, but the area of the atheromatous lesion was about one tenth of that in rats fed the high-cholesterol diet. Normal rats did not develop atherosclerosis even when fed the high-cholesterol diet for one year. The alloxan diabetic rats showed no increase in body weight, but developed serum glucose levels as high as 600-800 mg/dl as well as high serum cholesterol levels and lower serum HDL-cholesterol levels. The development of atherosclerosis in these rats was significantly related to an increase in the serum cholesterol/phospholipid ratio, the atherogenic index (TC-HDLC/HDLC), and the serum total cholesterol level, but was not related to the serum glucose, HDL-cholesterol, triglyceride, or lipid peroxide levels. These relationships were found as early as B-16 weeks after the start of the experiment. These data suggest that the serum cholesterol/phospholipid ratio, the atherogenic index, and the total cholesterol level are important risk factors for the development of atherosclerosis in rats with alloxan diabetes.     

Supplemental arginine and ornithine do not affect splenocyte proliferation in surgically treated rats

The present study was designed to determine whether arginine or ornithine supplementation enhanced immune responsiveness in surgically stressed rats. Young rats (130 to 150 g; n = 72) were fed one of three nonpurified diets: control, arginine-supplemented (30 g/kg of diet), or supplemented with ornithine on an equimolar basis to supplemental arginine. Control and ornithine-supplemented diets were made isonitrogenous to the arginine-supplemented diet with alanine. Food intake and body weight were monitored throughout the experimental period. Eight days after initiation of dietary treatments, 36 rats were given dorsal skin wounds. Rats were killed 7 days later. Blood was collected, spleen and thymus were weighed, and splenocytes were isolated to measure proliferation in response to mitogens and interleukin-2 production. Food intake, body weight gain, and thymus weight were lower in rats subjected to surgery than in controls rats (p < .01). Neither supplemental dietary arginine nor ornithine affected food intake, body weight gain, thymus weight, splenocyte proliferation, or splenocyte interleukin-2 production in any treatment group (p < .1). These data suggest that low-level dietary supplementation of arginine and ornithine did not ameliorate detrimental effects of minor surgery in rats.     

Lithogenic diet and gallstone formation in mice: integrated response of activities of regulatory enzymes in hepatic cholesterol metabolism

Supersaturation of bile with cholesterol is a prerequisite of the development of gallstones. With the intention to study the integrated response of enzymes regulating hepatic cholesterol metabolism during gallstone formation we used an established model for the induction of cholesterol gallstone disease in mice. Ten mice were fed on a lithogenic diet containing 10 g cholesterol/kg and 5 g cholic acid/kg for 8 weeks and were compared with ten mice fed on a standard pellet diet. Cholesterol crystals or gallstones developed in 90% of gallbladders in treated mice. The lithogenic diet had an inhibitory effect on the rate-limiting enzyme of cholesterol biosynthesis, hepatic 3-hydroxy-3-methylglutaryl-CoA (HMG-CoA) reductase (EC 1.1.1.88) activity, 39.6 (SEM 2.8) v. 171.0 (SEM 47.3) pmol/min per mg protein. Cholesterol 7 alpha-hydroxylase (EC 1.14.13.17) activity, regulating bile acid synthesis, was decreased by 80%, and this was assumed to be due to cholic acid in the diet. The cholesterol-enriched diet also induced a tenfold increase in cholesterol esterification rate in the liver, i.e. acyl-CoA:cholesterol acyl transferase (ACAT; EC 2.3.1.26) activity. The total, as well as esterified, cholesterol contents of liver homogenates were significantly higher in cholesterol- and cholic acid-treated mice and correlated well with the ACAT activity (rs 0.72 (P < 0.005), and rs 0.68 (P < 0.01) respectively). A significantly higher ACAT activity was obtained in mice given cholesterol and cholic acid even when the enzyme was saturated with exogenous cholesterol, thus indicating an increased amount of the enzyme. The formation of gallstones is dependent on a delicate balance between lithogenic factors (increased absorption of cholesterol and reduced secretion of bile acids) and defence mechanisms (decreased synthesis and increased esterification of cholesterol). In the specific animal model studied here the two defence mechanisms cannot compensate for the increased absorption of cholesterol and the reduced synthesis of bile acids.     

Two cases of spotted fever group rickettsiosis contracted in southern parts of Africa

The effect of Ogi-Keishi-Gomotsu-To-Ka-Kojin (OKGK), a traditional Chinese herbal medicine (Kampo medicine), on cholesterol metabolism was studied in male Sprague-Dawley rats. Intake of OKGK at doses of 1.38 g/kg for 4 weeks significantly reduced total cholesterol levels in the serum and liver of hypercholesterolemia rats fed a cholesterol-enriched diet. OKGK suppressed cholesterol absorption through the intestine and stimulated excretion of cholesterol into feces as bile acids. Biochemical study indicated that OKGK treatment enhanced cholesterol 7alpha-hydroxylase activity the rate limiting enzyme of cholic acid synthesis, in the liver without any effect on the rate limiting enzyme of cholesterol synthesis, 3-hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) reductase. Further, cholesterol-enriched diet containing cholic acid suppressed cholesterol 7alpha-hydroxylase activity, whereas OKGK administration reversed the suppression. In conclusion, these results supported the idea that OKGK may be an effective agent for treatment of patients with hypercholesterolemia.     

Dietary stearic acid reduces plasma and hepatic cholesterol concentrations without increasing bile acid excretion in cholesterol-fed hamsters

Although there is general agreement that saturated fatty acids elevate plasma cholesterol concentrations, the relative effects of individual fatty acids on cholesterol and bile acid metabolism are less clear. In this study, cholesterol and bile acid responses to diets enriched in different saturated fatty acids were investigated in hamsters. The six diets examined were as follows: 5% fat (g/100 g) enriched in palmitic acid (16:0) with no cholesterol, 5% fat 16:0-enriched, 0.05% cholesterol (wt/wt), and four diets containing 0.05% cholesterol and 15% fat with each diet enriched in lauric (12:0), myristic (14:0), palmitic (16:0), or stearic acid (18:0). Total plasma cholesterol concentration was significantly greater in hamsters fed the 14:0-enriched diet relative to those fed the 18:0-enriched diet (P < 0.05). Both plasma and liver cholesterol concentrations of hamsters fed 18:0 did not differ from those of the group fed no dietary cholesterol. In all instances, differences in total plasma cholesterol were accounted for within the HDL fraction; no significant treatment differences in VLDL or LDL cholesterol were found. Total daily fecal bile acid excretion was higher in hamsters fed the 15% fat 16:0 diet compared with those fed no dietary cholesterol (P < 0.05), but not significantly different from other treatment groups. There was greater deoxycholic acid excretion (P < 0.05) from hamsters fed the 14:0 and 16:0 diets compared with those fed the 18:0-enriched diet. Small intestinal + gallbladder bile acids, an index of pool size, did not differ significantly among the groups. The observed relative hypocholesterolemic effect of stearic acid was not mediated by increased bile acid excretion.     

Surgical management of retinal detachments related to coloboma of the choroid

We examined the influence of extruded chickpeas and wheat relative to casein and wheat in a dimethylhydrazine (DMH)-induced colon tumor study in male Sprague-Dawley rats. The three diets, based on a modified AIN76 rodent diet with fat present at 10 g/100 g dry matter (DM), were as follows: casein with wheat starch (Cas/S) as control, casein with wheat (Cas/W) and chickpeas with wheat (CP/W). All diets were fed from 5 wk of age throughout the 28-wk study. At 28 wk, there was a significantly lower incidence of large intestinal tumors in rats fed Cas/W relative to those fed CP/W ( 11 vs. 56%, chi-square test, P = 0.018). The colonic tumor burden (tumors/tumor-bearing animal) was not different in Cas/W-fed and CP/W-fed rats (1 vs. 1.7), but the tumor mass index was significantly lower in the former group (0.22 vs. 1.21, P = 0.026). Rats fed the CP/W diet had significantly lower plasma cholesterol concentration (P < 0.01) than rats fed the other two diets. The cecal contents of rats fed the CP/W diet had significantly greater relative weights (46%, P < 0.05) than those of the Cas/W-fed rats; this was associated with higher concentrations of all short-chain fatty acids. Fecal analyses showed significantly (P < 0.05) higher concentrations of total fat (54%), total steroids (83%) and secondary bile acids (179%) in the CP/W-fed rats relative those fed Cas/W. There were higher concentrations of nitrogen in the feces of CP/W rats relative to the Cas/W-fed rats (84%, P < 0.05), associated with greater fecal weights (67%, P < 0.05). Although wheat and its fibers have been shown to be protective against DMH-induced cancers in rats, this was not the case in this study in which chickpeas (45 g/100 g diet) provided the protein and were an important source of soluble fiber. Elevated fat, secondary bile acid concentrations and/or nitrogenous compounds could be responsible for the increased colon tumorigenesis seen and may reflect a legume effect.     

Different cholesterol deposition in aorta of Dahl salt-sensitive rats and spontaneously hypertensive rats fed a high-cholesterol diet

1. We compared the serum and aortic lipid levels in spontaneously hypertensive rats (SHR) and Dahl salt-sensitive rats (DSR) fed a high-cholesterol (HC) diet. 2. In SHR fed the HC diet, the serum cholesterol level significantly increased, but no aortic cholesterol deposition was observed. 3. The serum cholesterol level in DSR fed the HC diet markedly increased compared to that in DSR fed the basal diet, and this change was greater with the diet containing 8% NaCl than 0.4% NaCl. A significant increase in the content of aortic cholesterol, notably cholesteryl ester, was observed in only DSR fed the HC diet containing 8% NaCl. 4. These results suggest that the combination of hypercholesterolaemia with salt-induced hypertension acts as a greater risk factor for atherosclerosis than that with genetic hypertension.     

Increased bile acid pool inhibits cholesterol 7 alpha-hydroxylase in cholesterol-fed rabbits

BACKGROUND & AIMS: Cholesterol feeding unexpectedly inhibits cholesterol 7 alpha-hydroxylase in rabbits. The aim of this study was to explore the mechanism. METHODS: Twenty male New Zealand white rabbits were fed regular chow with and without 2% cholesterol for 10 days followed by 7 days of bile drainage. The activities of hepatic cholesterol 7 alpha-hydroxylase and sterol 27-hydroxylase that control bile acid synthesis in classic and alternative pathways were related to the size and composition of bile acid pool. RESULTS: After feeding cholesterol, plasma and hepatic cholesterol concentrations increased, the bile acid pool doubled (from 254 +/- 44 to 533 +/- 51 mg; P < 0.001), cholesterol 7 alpha-hydroxylase activity decreased 68% (P < 0.01), but sterol 27-hydroxylase activity increased 66% (P < 0.05) with increased cholic acid synthesis (P < 0.01). Bile drainage in the cholesterol-fed rabbits depleted the bile acid pool and stimulated down-regulated cholesterol 7 alpha-hydroxylase activity 11.4-fold (P < 0.001), although hepatic cholesterol remained elevated. Hepatic sterol 27-hydroxylase activity was unaffected. CONCLUSIONS: Feeding cholesterol increased hepatic cholesterol and stimulated sterol 27-hydroxylase and alternative bile acid synthesis, which expanded the bile acid pool and inhibited cholesterol 7 alpha-hydroxylase in rabbits. In distinction, hepatic sterol 27-hydroxylase was insensitive to changes in the bile acid pool.     

Hypocholesterolemic action of Lactobacillus acidophilus ATCC 43121 and calcium in swine with hypercholesterolemia induced by diet

Thirty-three Yorkshire barrows (92 kg), fed a high cholesterol diet for 14 d had mean concentrations of serum cholesterol of 294.6 +/- 7.8 mg/dl. Starting on d 15 and for an additional 15 d, crystalline cholesterol was removed from the diet and pigs were assigned to one of four treatments: including two levels of calcium (0.7% and 1.4%) with and without added viable Lactobacillus acidophilus ATCC 43121 (2.5 x 10(11) cells per feeding). Serum cholesterol levels decreased, as expected, for all groups. However, the declines were initiated sooner for the groups receiving L. acidophilus. and those receiving the high level of calcium than for the respective control groups. When averaged over days, pigs fed L. acidophilus had 11.8% lower total cholesterol than pigs fed a diet without L. acidophilus. Similarly, pigs fed 1.4% calcium had a significantly lower total cholesterol than pigs fed 0.7% calcium. The effects were greater on low density lipoprotein cholesterol than on high density lipoprotein cholesterol. In addition, during the overall 15-d experimental period, serum bile acids were reduced 23.9% by dietary L. acidophilus and by 21.4% by 1.4% dietary calcium compared with those of their controls. Total bile acid concentration was positively correlated with total cholesterol concentration for pigs fed L. acidophilus or 1.4% calcium. These data suggest that both L. acidophilus and calcium can enhance the reduction of serum cholesterol in pigs that had been fed a high cholesterol diet, probably through alteration in the enterohepatic circulation of bile acids.     

Effects of a mixture of organisms, Lactobacillus acidophilus or Streptococcus faecalis on cholesterol metabolism in rats fed on a fat- and cholesterol-enriched diet

The effect of a mixture of organisms (a probiotic mixture) comprising Bacillus, Lactobacillus, Streptococcus, Clostridium, Saccharomyces and Candida (10(7-8) colony-forming units/g rice bran of each component) on lipid metabolism was compared with that of L. acidophilus and that of S. faecalis. There were four treatment groups: rice bran (control), the mixture of organisms, L. acidophilus or S. faecalis (30 g/kg) were given to rats in a fat- and cholesterol-enriched diet for 4 weeks. The serum total cholesterol concentration of the group fed on the mixture of organisms was reduced by 15-33% compared with the other groups at the end of the 4-week feeding period (P < 0.05). This group also had a lower hepatic cholesterol concentration (36-44%) than the two single-bacteria groups (P < 0.05). 3-Hydroxy-3-methylglutaryl-Co A reductase (NADPH; EC 1.1.1.34) activities of the mixed-organism and L. acidophilus groups were significantly lower (61-63%) than those of the other groups (P < 0.05); the activity of the S. faecalis group was also significantly lower (42%) than that of the control group (P < 0.05). The faecal cholesterol and bile acid concentrations of the mixed-organism group increased compared with those of the L. acidophilus and S. faecalis groups (P < 0.05). The capacity of the mixed-organism cells to bind bile salt in vitro was significantly higher (approximately 50%) than that of the single-bacteria cells (P < 0.05). On the other hand, cholesterol micelle formation for the mixed-organism cells was significantly (approximately 9%) lower than that of the single-bacteria cells (P < 0.05). These results indicate that the mixture of organisms decreased the synthesis of cholesterol in the liver and increased the loss of steroids from the intestine, in rats. Thus, the mixture of organisms had a hypocholesterolaemic role.     

Optimum dietary arginine:lysine ratio for broiler chickens is altered during heat stress in association with changes in intestinal uptake and dietary sodium chloride

1. The effects of varying the dietary arginine:lysine (Arg:Lys) ratio for broiler chickens at thermoneutral and high temperatures was studied in a series of 5 experiments which measured intestinal epithelial transport or evaluated growth and food efficiency with practical diets or diets supplemented with L-arginine free base. 2. The growth studies showed that increasing the Arg:Lys ratio at high temperatures produced consistent improvements in food conversion without any loss in growth. 3. Increasing dietary sodium chloride concentration reduced the Arg:Lys ratio necessary for optimum food conversion. 4. Food conversion responses were improved whether L-arginine free base was used as a dietary supplement in place of an inert filler or practical diets with differing ingredients were used to vary the Arg:Lys ratio. 5. In the presence of an equimolar concentration of lysine the uptake of arginine by the intestinal epithelium of heat-stressed broilers was reduced significantly compared with that of broilers at thermoneutral temperatures. 6. The results indicate that the ideal amino acid balance for broilers varies with ambient temperature.     

Altered migrating myoelectrical complex in an animal model of cholesterol gallstone disease: the effect of erythromycin

BACKGROUND: The ground squirrel on a high cholesterol diet exhibits prolonged intestinal transit, a pathogenetic factor in cholesterol gallstone formation. AIMS: To examine the effect of a high cholesterol diet on the characteristics of the migrating myoelectrical complex (MMC) and the potential benefit of erythromycin. METHODS: Twenty four animals received either a trace (controls) or a 1% (high) cholesterol diet. After four weeks, five bipolar jejunal and terminal ileal electrodes were implanted. Seven days later, myoelectric activity was measured in conscious, fasted animals before and after treatment with erythromycin. Biliary lipid composition was assessed. RESULTS: Compared with controls, animals fed the high cholesterol diet exhibited a prolonged MMC cycle period (70 (6) versus 83 (3) minutes; p<0.05), whereas MMC migration velocity and the proportions of the MMC represented by phases I, II, and III were unchanged. Oral erythromycin significantly shortened the MMC cycle period in animals on the control and high cholesterol diet by 59% and 54% respectively, and increased the proportion of the cycle period occupied by phase III of the MMC in both dietary groups. Gall bladder bile became saturated with cholesterol and crystals developed in nine of 12 animals on the high cholesterol diet; controls had none. CONCLUSION: Animals fed a high cholesterol diet had a prolonged MMC cycle period. This, along with diminished gall bladder motility, impairs the enterohepatic cycling of bile salts and reduces their hepatic secretion, contributing to the formation of abnormal bile. Erythromycin initiated more frequent cycling of the MMC. Its therapeutic value in cholesterol gallstone formation warrants further evaluation.     

Cholestyramine and a fat-free diet lower apolipoprotein A-IV mRNA in jejunum and cholestyramine lowers apolipoprotein A-I mRNA in ileum of rats

To investigate the effect of bile acids or dietary lipid on the expression of intestinal apolipoproteins, the mRNA levels of apolipoprotein A-I and A-IV in the intestine from rats fed a diet containing cholestyramine or a fat-free diet were compared with those from rats fed a control diet containing 25% casein and 5% corn oil. Plasma total cholesterol concentration was lower after 16 h in rats fed a diet containing cholestyramine or a fat-free diet than in rats fed a control diet. In rats fed the fat-free diet, HDL cholesterol concentration also was lower than in those fed the control diet. The pool of bile acid in intestinal contents was significantly lower in rats fed cholestyramine than in both other groups. The relative abundance of jejunal apolipoprotein A-I mRNA did not differ between groups. Jejunal apolipoprotein A-IV mRNA abundance was significantly lower than in controls in rats fed the fat-free and cholestyramine-containing diets. Abundance of apolipoprotein A-I mRNA in ileal mucosa was comparable to controls in rats fed a fat-free diet but was significantly lower in rats fed cholestyramine. Ileal apolipoprotein A-IV mRNA tended to be lower in rats fed cholestyramine and a fat-free diet than in controls. We propose that decreased absorption of dietary lipid may modulate changes in jejunal apolipoprotein A-IV mRNA level and low levels of bile acids in the lumen may modulate changes in ileal apolipoprotein A-I mRNA level.