Effects of protein tyrosine kinase and protein tyrosine phosphatase on apical K(+) channels in the TAL

We havepreviously demonstrated that the protein level of c-Src, anonreceptor type of protein tyrosine kinase (PTK), was higher in therenal medulla from rats on a K-deficient (KD) diet than that in rats ona high-K (HK) diet (Wang WH, Lerea KM, Chan M, and Giebisch G. Am J Physiol Renal Physiol 278: F165-F171, 2000).We have now used the patch-clamp technique to investigate the role ofPTK in regulating the apical K channels in the medullary thickascending limb (mTAL) of the rat kidney. Inhibition of PTK withherbimycin A increased NP_o, a product of channelnumber (N) and open probability (P_o),of the 70-pS K channel from 0.12 to 0.42 in the mTAL only from rats ona KD diet but had no significant effect in tubules from animals on a HKdiet. In contrast, herbimycin A did not affect the activity of the30-pS K channel in the mTAL from rats on a KD diet. Moreover, additionof N-methylsulfonyl-12,12-dibromododec-11-enamide, an agentthat inhibits the cytochrome P-450-dependent production of20-hydroxyeicosatetraenoic acid, further increasedNP_o of the 70-pS K channel in the presence ofherbimycin A. Furthermore, Western blot detected the presence ofPTP-1D, a membrane-associated protein tyrosine phosphatase (PTP), inthe renal outer medulla. Inhibition of PTP with phenylarsine oxide(PAO) decreased NP_o of the 70-pS K channel inthe mTAL from rats on a HK diet. However, PAO did not inhibit theactivity of the 30-pS K channel in the mTAL. The effect of PAO on the70-pS K channel was due to indirectly stimulating PTK becausepretreatment of the mTAL with herbimycin A abolished the inhibitoryeffect of PAO. Finally, addition of exogenous c-Src reversibly blockedthe activity of the 70-pS K channel in inside-out patches. We concludethat PTK and PTP have no effect on the low-conductance K channels inthe mTAL and that PTK-induced tyrosine phosphorylation inhibits,whereas PTP-induced tyrosine dephosphorylation stimulates, the apical70-pS K channel in the mTAL.

     

Brain changes in BDNF and S100B induced by ketogenic diets in Wistar rats

AimsWe investigated the effects of ketogenic diet (KD) on levels of tumor necrosis factor alpha (TNF-α, a classical pro-inflammatory cytokine), BDNF (brain-derived neurotrophic factor, commonly associated with synaptic plasticity), and S100B, an astrocyte neurotrophic cytokine involved in metabolism regulation.Main methodsYoung Wistar rats were fed during 8 weeks with control diet or two KD, containing different proportions of omega 6 and omega 3 polyunsaturated fatty acids. Contents of TNF-α, BDNF and S100B were measured by ELISA in two brain regions (hippocampus and striatum) as well as blood serum and cerebrospinal fluid.Key findingsOur data suggest that KD was able to reduce the levels of BDNF in the striatum (but not in hippocampus) and S100B in the cerebrospinal fluid of rats. These alterations were not affected by the proportion of polyunsaturated fatty acids offered. No changes in S100B content were observed in serum or analyzed brain regions. Basal TNF-α content was not affected by KD.SignificanceThese findings reinforce the importance of this diet as an inductor of alterations in the brain, and such changes might contribute to the understanding of the effects (and side effects) of KD in brain disorders.     

K depletion enhances the extracellular Ca2+-induced inhibition of the apical K channels in the mTAL of rat kidney.

We have shown previously that raising extracellular Ca(2)+ inhibited the apical 70-pS K channel in the thick ascending limb (TAL; Wang, W.H., M. Lu, and S.C. Hebert. 1996. Am. J. Physiol. 270:C103-C111). We now used the patch-clamp technique to study the effect of increasing the extracellular Ca(2)+ on the 70-pS K channel in the mTAL from rats on a different K diet. Increasing the extracellular Ca(2)+ from 10 microM to 0.5, 1, and to 1.5 mM in the mTAL from rats on a K-deficient (KD) diet inhibited the channel activity by 30, 65, and 90%, respectively. In contrast, raising the extracellular Ca(2)+ to 1.5 mM had no significant effect on channel activity in the mTAL from animals on a high K (HK) diet and further increasing the extracellular Ca(2)+ to 2.5, 3.5, and 5.5 mM decreased the channel activity by 29, 55, and 90%, respectively. Inhibition of the cytochrome P450 monooxygenase completely abolished the effect of the extracellular Ca(2)+ on channel activity in the mTAL from rats on a different K diet. In contrast, blocking cyclooxygenase did not significantly alter the responsiveness of the 70-pS K channel to the extracellular Ca(2)+. Moreover, addition of sodium nitropruside, a nitric oxide (NO) donor, not only increased the channel activity, but also blunted the inhibitory effect of the extracellular Ca(2)+ on the 70-pS K channel and decreased 20-hydroxyeicosatetraenoic acid (20-HETE) concentration in the mTAL from rats on a KD diet. In contrast, inhibiting NOS with L-NAME enhanced the inhibitory effect of the extracellular Ca(2)+ on the channel activity and increased 20-HETE concentration in the mTAL from rats on a high K diet. Western blot has further shown that the expression of inducible NO synthase (iNOS) is significantly higher in the renal medulla from rats on an HK diet than that on a KD diet. Also, addition of S-nitroso-N-acetylpenicillamine abolished the inhibitory effect of arachidonic acid on channel activity in the mTAL, whereas it did not block the inhibitory effect of 20-HETE. We conclude that a low dietary K intake increases the sensitivity of the 70-pS K channel to the extracellular Ca(2)+, and that a decrease in NOS activity is involved in enhancing the inhibitory effect of the extracellular Ca(2)+ on channel activity in the mTAL during K depletion.     

Endurance in high-fat-fed rats: effects of carbohydrate content and fatty acid profile

The purpose ofthis experiment was to study endurance performance and substratestorage and utilization in fat- or carbohydrate-fed rats. Ninety-ninerats were randomly divided into three groups and over 4 wk were fedeither a carbohydrate-rich [CHO; 10% total energy content in the diet(E%) fat, 20 E% protein, 70 E% carbohydrate] diet or one of twofat-rich diets (65 E% fat, 20 E% protein, 15 E% carbohydrate)containing either saturated (Sat) or monounsaturated fatty acids(Mono). Each dietary group was randomly assigned to a trained (6 days/wk, progressive to 60 min, 28 m/min at a 10% incline) or asedentary group. Rats were killed either before or after a treadmillendurance run to exhaustion. Training increased endurance (206%), butdiet composition did not affect endurance in either trained orsedentary rats. -Hydroxyacyl-CoA dehydrogenase activity wasincreased in fat-fed but not carbohydrate-fed rats (P < 0.05). Respiratory exchangeratio during the initial phase of exercise was lower after the Monocompared with the Sat diet (P < 0.05) and higher after the CHO than the Sat diet(P < 0.05). Thus adaptation to ahigh-fat diet containing a moderate amount of carbohydrates did notinduce enhanced endurance in either trained or untrained rats; however,substrate utilization was modulated by both amount and type of dietaryfat during the initial stage of exercise in trained and sedentary rats.

     

Magnification of the therapeutic uses of pomegranate fruits and peel in rats injected with carbon tetrachloride (Ccl4)

The liver is more prone to infections that cause fibrosis, such as steatosis, non-alcoholic steatohepatitis, hepatotoxicity, cirrhosis, and hepatocellular carcinoma. Also, Viral hepatitis is a common condition worldwide it worsens into chronic inflammation of the liver. One of the healthiest fruits is the pomegranate for the body and health, as it contains a high nutritional value of minerals, vitamins, antioxidants, so we worked on this investigation to magnify the therapeutic applications of pomegranate fruits (POF) and peel (POP) in carbon tetrachloride-injected rats (Ccl4). The experiment was carried out in a caged animal. All rats were fed a basal diet for one week before the study, and they were divided into seven groups, each with six rats. As a control negative group (C–ve), the first group sample was fed only the basal diet for 28 days. The remaining rats (n = 36) were injected with carbon tetrachloride (Ccl4). Five groups were fed varying concentrations of (5 %, 10 %, 15 % POF, 5 %, and 10 % pomegranate peel (POP)), whereas one group was diagnosed with the illness and disease, and didn't even feed the experimental diet. The results revealed significant increases in T.BIL, D.BIL, and BIL in the serum of rats injected by CC14 to induce hepatopathy compared to the healthy group (normal rats). Also, the best treatment considering the serum D.BIL was recorded for the 5 % POF.     

The ketogenic diet increases mitochondrial glutathione levels

The ketogenic diet (KD) is a high-fat, low carbohydrate diet that is used as a therapy for intractable epilepsy. However, the mechanism(s) by which the KD achieves neuroprotection and/or seizure control are not yet known. We sought to determine whether the KD improves mitochondrial redox status. Adolescent Sprague–Dawley rats (P28) were fed a KD or control diet for 3 weeks and ketosis was confirmed by plasma levels of β-hydroxybutyrate (BHB). KD-fed rats showed a twofold increase in hippocampal mitochondrial GSH and GSH/GSSG ratios compared with control diet-fed rats. To determine whether elevated mitochondrial GSH was associated with increased de novo synthesis, the enzymatic activity of glutamate cysteine ligase (GCL) (the rate-limiting enzyme in GSH biosynthesis) and protein levels of the catalytic (GCLC) and modulatory (GCLM) subunits of GCL were analyzed. Increased GCL activity was observed in KD-fed rats, as well as up-regulated protein levels of GCL subunits. Reduced CoA (CoASH), an indicator of mitochondrial redox status, and lipoic acid, a thiol antioxidant, were also significantly increased in the hippocampus of KD-fed rats compared with controls. As GSH is a major mitochondrial antioxidant that protects mitochondrial DNA (mtDNA) against oxidative damage, we measured mitochondrial H₂O₂ production and H₂O₂-induced mtDNA damage. Isolated hippocampal mitochondria from KD-fed rats showed functional consequences consistent with the improvement of mitochondrial redox status i.e. decreased H₂O₂ production and mtDNA damage. Together, the results demonstrate that the KD up-regulates GSH biosynthesis, enhances mitochondrial antioxidant status, and protects mtDNA from oxidant-induced damage.     

Dietary selenium requirements based on tissue selenium concentration and glutathione peroxidase activities in old female rats

Dietary nutrient requirements for older animals have been studied far less than have requirements for young growing animals. To determine dietary selenium (Se) requirements in old rats, we fed female weanling rats a Se-deficient diet (0.007 μg Se/g) or supplemented rats with graded levels of dietary Se (0–0.3 μg Se/g) as Na₂SeO₃ for 52 weeks. At no point did Se deficiency or level of Se supplementation have a significant effect (P>0.05) on growth. To determine Se requirements, Se response curves were determined for 7 Se-dependent parameters. We found that minimum dietary Se requirements in year-old female rats were at or below 0.05 μg Se/g diet based on liver Se, red blood cell glutathione peroxidase (Gpx1) activity, plasma Gpx3 activity, liver and kidney Gpx1 activity, and liver and kidney Gpx4 activity. In conclusion, this study found that dietary Se requirements in old female rats were decreased at least 50% relative to requirements found in young, rapidly growing female rats. Collectively, this indicates that the homeostatic mechanisms related to retention and maintenance of Se status are still fully functional in old female rats.     

l-Lysine supplementation does not affect the bioavailability of copper or iron in rats

l-lysine (Lys) is an essential amino acid that is added to foods and dietary supplements. Lys may interact with mineral nutrients and affect their metabolism. This study examined the effect of dietary Lys supplementation on the bioavailability of copper (Cu) and iron (Fe). Weanling male Sprague-Dawley rats were fed one of five diets (20% casein) for 4 weeks containing normal Cu and Fe (control) or low Cu or Fe without (LCu, LFe) or with (LCu + Lys, LFe + Lys) addition of 1.5% Lys. Final body weights, body weight gains and food consumption of the rats did not differ (P ≥ 0.05) among diet groups. Rats fed the low Cu or Fe diets showed changes in nutritional biomarkers compared to control rats, demonstrating reduced Cu and Fe status, respectively. Hematological parameters, serum ceruloplasmin activity and Cu and Fe concentrations in serum, liver, kidney and intestinal mucosa were unaffected (P ≥ 0.05) by Lys supplementation. These results indicate that in the context of an adequate protein diet, Lys supplementation at a relatively high level does not affect Cu or Fe bioavailability in rats.     

Adaptation to short-term extreme fat consumption alters intestinal lipid handling in male and female mice

The small intestine is a highly adaptable organ serving as both a barrier to the external environment and a conduit for nutrient absorption. Enterocytes package dietary triglycerides (TG) into chylomicrons for transport into circulation; the remaining TGs are stored in cytosolic lipid droplets (CLDs). The current study aimed to characterize the impact of diet composition on intestinal lipid handling in male and female wild-type mice. Mice were continued on their grain-based diet (GBD) and switched to either a high-fat, high cholesterol Western-style diet (WD) or a ketogenic diet (KD) for 3 or 5 weeks. KD-fed mice displayed significantly higher plasma TG levels in response to an olive oil gavage than WD- and GBD-fed mice; TG levels were ~2-fold higher in male KD-fed mice than female KD-fed mice. Poloxamer-407 experiments revealed enhanced intestinal-TG secretion rates in male mice fed a KD upon olive oil gavage, whereas secretion rates were unchanged in female mice. Surprisingly, jejunal CLD size and TG mass after oil gavage were similar among the groups. At fasting, TG mass was significantly higher in the jejunum of male KD-fed mice and the duodenum of female KD-fed mice, providing increased substrate for chylomicron formation. In addition to greater fasting intestinal TG stores, KD-fed male mice displayed longer small intestinal lengths, while female mice displayed markedly longer jejunal villi lengths. After 5 weeks of diet, 12 h fasting-2 h refeeding experiments revealed jejunal TG levels were similar between diet groups in male mice; however, in female mice, jejunal TG mass was significantly higher in KD-fed mice compared to GBD- and WD-fed mice. These experiments reveal that KD feeding promotes distinct morphological and functional changes to the murine small intestine compared to the WD diet. Moreover, changes to intestinal lipid handling in response to carbohydrate and protein restriction manifest differently in male and female mice.     

Evaluation of the effect of cafeteria diet on the kidney Na,K-ATPase activity,and oxidative stress

In this study, renal tissue, subdivided into the cortex and medulla of Wistar rats subjected to a cafeteria diet (CAF) for 24 days or to normal diet, was used to analyze whether the renal enzyme Na,K-ATPase activity was modified by CAF diet, as well as to analyze the α1 subunit of renal Na,K-ATPase expression levels. The lipid profile of the renal plasma membrane and oxidative stress were verified. In the Na,K-ATPase activity evaluation, no alteration was found, but a significant decrease of 30% in the cortex was detected in the α1 subunit expression of the enzyme. There was a 24% decrease in phospholipids in the cortex of rats submitted to CAF, a 17% increase in cholesterol levels in the cortex, and a 23% decrease in the medulla. Lipid peroxidation was significantly increased in the groups submitted to CAF, both in the cortical region, 29%, and in the medulla, 35%. Also, a reduction of 45% in the glutathione levels was observed in the cortex and medulla with CAF. CAF showed a nearly two-fold increase in glutathione peroxidase (GPX) activity in relation to the control group in the cortex and a 59% increase in the GPx activity in the medulla. In conclusion, although the diet was administered for a short period of time, important results were found, especially those related to the lipid profile and oxidative stress, which may directly affect renal function.     

Leucine and citrulline modulate muscle function in malnourished aged rats

Protein energy malnutrition in the elderly causes preferential loss of muscle mass which is associated with poor functional states. Leucine and citrulline are able to stimulate muscle protein synthesis in aged rats but no study has been undertaken to evaluate their effect on muscle function. Sprague–Dawley male rats aged 23 months were used in the experiment. Part of them were subjected to a dietary restriction for 12 weeks and then assigned to four groups: a group was euthanized (restricted group), and the others were refed for 1 week with either a leucine-, a citrulline-supplemented diet, or a standard diet. The other rats were fed ad libitum. Muscle mass and motor activity significantly increased during the refeeding with either leucine or citrulline (respectively, +51 and +37% for muscle mass, P < 0.05). The improvement of muscle mass and of motor activity induced by leucine and citrulline was highly associated with that of maximal tetanic isometric force (r = 0.769, P < 0.0001; r = 0.389, P < 0.05, respectively) but only leucine improved maximal tetanic isometric force (+101%, P < 0.05). In conclusion, this is the first study to demonstrate the ability of two amino acids (leucine and citrulline) to modulate muscle function.     

Effect of chronic ethanol ingestion on phosphate content of neurofilament proteins and neurofilament associated protein phosphatase in rat spinal cord

Rats were trained to drink alcohol solution by gradually increasing the ethanol content [2.5–15% (v/v)] in drinking water. After 11 months of alcohol (15% v/v) ingestion, animals were guillotined and the spinal cords were used for the preparation of neurofilaments (NF). NF triplet proteins were separated by SDS-PAGE and the phosphate contents of individual components were estimated. Results indicated a significant increase in phosphate content of 200 KD protein in alcohol fed rats (30.19±4.12 mol of phosphate/mole of protein: p<0.001) compared to control group (18.42 ±3.91 mol of phosphate/mole of protein). No significant change in the phosphate content of 150KD and 68KD components of NF were seen in experimental group. Further, the studies on NF associated protein phosphatase activity indicated a significant decrease in phosphatase activity among the alcohol fed rats (14.10±2.5 mU; p<0.001) against NF rich fraction as a substrate, as compared to control (20.15±2.15 mU). While the observed decrease in NF associated protein phosphatase would possibly explain the increase in phosphate content of NF proteins in alcohol fed rats, the precise mechanism of decrease in enzyme activity remains to be elucidated. Nevertheless, the change seen in phosphate content and NF associated protein phosphatase activity as a result of ethanol ingestion would possibly form the biochemical basis of some of the neuropathological changes seen in alcoholics.     

Dietary flaxseed reduces Myocardial Ischemic Lesions,improves cardiac function and lowers cholesterol levels despite the presence of severe obesity in JCR:LA-cp Rats

Previous work has shown that dietary flaxseed can significantly reduce cardiac damage from a coronary artery ligation-induced myocardial infarction. However, this model uses healthy animals and the ligation creates the infarct in an artificial manner. The purpose of this study was to determine if dietary flaxseed can protect the hearts of JCR:LA-cp rats, a model of genetic obesity and metabolic syndrome, from naturally occurring myocardial ischemic lesions. Male and female obese rats were randomized into four groups (n = 8 each) to receive, for 12 weeks, either a) control diet (Con), b) control diet supplemented with 10% ground flaxseed (CFlax), c) a high-fat, high sucrose (HFHS) diet, or d) HFHS supplemented with 10% ground flaxseed (HFlax). Male and female JCR:LA-cp lean rats served as genetic controls and received similar dietary interventions. In male obese rats, serum total cholesterol and LDL-C were significantly lower in CFlax compared to Con.  Obese rats on HFHS exhibited increased myocardial ischemic lesions and diastolic dysfunction regardless of sex. HFlax significantly lowered the frequency of cardiac lesions and improved diastolic function in male and female obese rats compared to HFHS. Blood pressures were similar in obese and lean rats. No aortic atherosclerotic lesions were detectable in any group. Collectively, this study shows that a HFHS diet increased myocardial ischemic lesion frequency and abolished the protective effect of female sex on cardiac function. More importantly, the data demonstrates dietary flaxseed protected against the development of small spontaneous cardiac infarcts despite the ingestion of a HFHS diet and the presence of morbid obesity.     

Nigella sativa thymoquinone-rich fraction greatly improves plasma antioxidant capacity and expression of antioxidant genes in hypercholesterolemic rats

The antioxidant activities of the thymoquinone-rich fraction (TQRF) extracted from Nigella sativa and its bioactive compound, thymoquinone (TQ), in rats with induced hypercholesterolemia were investigated. Rats were fed a semipurified diet supplemented with 1% (w/w) cholesterol and were treated with TQRF and TQ at dosages ranging from 0.5 to 1.5 g/kg and 20 to 100 mg/kg body wt, respectively, for 8 weeks. The hydroxyl radical (OH^·)-scavenging activity of plasma samples collected from experimental rats was measured by electron spin resonance. The GenomeLab Genetic Analysis System was used to study the molecular mechanism that mediates the antioxidative properties of TQRF and TQ. Plasma total cholesterol and low-density-lipoprotein cholesterol levels were significantly decreased in the TQRF- and TQ-treated rats compared to untreated rats. Feeding rats a 1% cholesterol diet for 8 weeks resulted in a significant decrease in plasma antioxidant capacity, as measured by the capacity to scavenge hydroxyl radicals. However, rats treated with TQRF and TQ at various doses showed significant inhibitory activity toward the formation of OH^· compared to untreated rats. Upon examination of liver RNA expression levels, treatment with TQRF and TQ caused the up-regulation of the superoxide dismutase 1 (SOD1), catalase, and glutathione peroxidase 2 (GPX) genes compared to untreated rats (P < 0.05). In support of this, liver antioxidant enzyme levels, including SOD1 and GPX, were also apparently increased in the TQRF- and TQ-treated rats compared to untreated rats (P < 0.05). In conclusion, TQRF and TQ effectively improved the plasma and liver antioxidant capacity and enhanced the expression of liver antioxidant genes of hypercholesterolemic rats.     

A leucine-rich diet and exercise affect the biomechanical characteristics of the digital flexor tendon in rats after nutritional recovery

An increase in the capacity of athletic performance depends on adequate nutrition, which ensures optimal function of the musculoskeletal system, including tendon stability. However, little is known about the status of tendons and extracellular matrix modifications during malnutrition and nutritional recovery when leucine is used in response to exercise conditioning. The purpose of this study was to evaluate the collagen content and biomechanical aspects of the deep digital flexor tendon (DDFT) in malnourished rats submitted to nutritional recovery (control diet or leucine-rich diet) and aerobic physical activity. After 60 days of undernourishment (6% protein diet), the malnourished rats were subsequently nutritionally recovered with a control diet or leucine-rich diet and trained or not (swimming, without overload) for 5 weeks. The biomechanical analysis and quantification of hydroxyproline were assessed in the DDFT in all experimental groups. The leucine-rich diet increased hydroxyproline content in the tension region, independently of the training. In the compression region, hydroxyproline content was higher in the malnourished and leucine-trained groups. Biomechanical analysis showed a lower load in the malnourished and all-trained groups. The lowest stress was observed with control-trained animals. The nutritional-recovered groups showed higher strain values corresponding to control group, while the lowest values were observed in malnourished and trained groups. The results suggest that a leucine-rich diet stimulates collagen synthesis of the DDFT, especially when in combination with physical exercise, and seems to determine the increase of resistance and the biomechanical characteristics of tendons.     

A high-fat, ketogenic diet induces a unique metabolic state in mice

Ketogenic diets have been used as an approach to weight loss on the basis of the theoretical advantage of a low-carbohydrate, high-fat diet. To evaluate the physiological and metabolic effects of such diets on weight we studied mice consuming a very-low-carbohydrate, ketogenic diet (KD). This diet had profound effects on energy balance and gene expression. C57BL/6 mice animals were fed one of four diets: KD; a commonly used obesogenic high-fat, high-sucrose diet (HF); 66% caloric restriction (CR); and control chow (C). Mice on KD ate the same calories as mice on C and HF, but weight dropped and stabilized at 85% initial weight, similar to CR. This was consistent with increased energy expenditure seen in animals fed KD vs. those on C and CR. Microarray analysis of liver showed a unique pattern of gene expression in KD, with increased expression of genes in fatty acid oxidation pathways and reduction in lipid synthesis pathways. Animals made obese on HF and transitioned to KD lost all excess body weight, improved glucose tolerance, and increased energy expenditure. Analysis of key genes showed similar changes as those seen in lean animals placed directly on KD. Additionally, AMP kinase activity was increased, with a corresponding decrease in ACC activity. These data indicate that KD induces a unique metabolic state congruous with weight loss.     

Influence of probiotic bacterium Bacillus cereus isolated from the gut of wild shrimp Penaeus monodon in turn as a potent growth promoter and immune enhancer in P. monodon

A probiotic bacterium isolated from the gut of wild shrimp Penaeus monodon rendered maximum antagonistic activity against shrimp pathogens and was capable of producing extracellular enzymes. The probiotic bacterium was identified as Bacillus cereus through 16S rRNA sequencing. The lyophilized B. cereus was supplemented with shrimp basal diet at four different concentrations (0.1–0.4%/100 g feed) in D1–D4 diets. The viability of probiotic bacterium in the test diets was evaluated during the study period at various time intervals. The viability ranged from 50.24 ± 1.42 to 180.34 ± 1.30 CFU/g in D1 to D3 diets on the 30th day, whereas it was slightly declined from 45.23 ± 1.30 to 169.13 ± 1.18 CFU/g during the 90th day of storage. A control diet (C), devoid of probiotic supplementation was also simultaneously prepared. During experimentation, P. monodon postlarvae (PL-15) were cultured in individual one tonne capacity FRP tanks in triplicates provided with equal amount of substratum (clay soil) and fed with these respective diets at ad libitum for 90 days. Survival was high (82.0 ± 1.60%) in D4 diet fed shrimp as against a low survival of 65.0 ± 1.33% displayed by control diet fed shrimp. Overall growth responses inferred that a maximum production of 10.45 ± 0.275 g, SGR of 4.40 ± 0.179% and a better FCR of 1.27 ± 0.081 were obtained in D4 diet fed shrimp. However, the water quality parameters showed nonsignificant (P > 0.05) variations among the control and the probiotic treated groups. The tested immunological parameters such as Total haemocyte count, phenoloxidase activity, respiratory burst activity, lysozyme activity, plasma protein concentration and bactericidal activity were higher in D4 diet fed P. monodon, when compared to that of other diets fed shrimp. It is therefore suggested that lyophilized probiotic B. cereus at a concentration of 0.4%/100 g feed was efficient in stimulating the growth and immunity in shrimp.     

Association between polymorphisms of matrix metalloproteinase 11 (MMP-11) and Kawasaki disease in the Korean population

AimsThis study was conducted to investigate the associations between single nucleotide polymorphisms (SNPs) of matrix metalloproteinases (MMPs) and Kawasaki disease (KD) in the Korean population.Main methodsA total 0f 101 KD patients and 306 healthy controls were examined. MMP7 (rs10502001, G/A, Arg77His), MMP11 (rs738792, T/C, Ala38Val), MMP12 (rs652438, A/G, Ile357Val) and MMP26 (rs2499953, A/G, Lys43Glu) genes were genotyped from the genomic DNA using direct sequencing. The results were then analyzed using logistic regression models, adjusting for gender as covariates.Key findingsThe four SNPs were in Hardy–Weinberg equilibrium. Only the MMP11 polymorphism (rs738792) was associated with KD. The SNP (rs738792) showed a statistically significant association with KD in the codominant (OR = 1.61, 95% CI = 1.11–2.34, P = 0.011) and dominant (OR = 1.92, 95% CI = 1.21–3.06, P = 0.006) models. However, there was no association between polymorphisms of other MMP genes and KD.SignificanceOverall, the results of this study indicate that MMP11 polymorphism may be associated with KD in the Korean population.     

Fructose-induced hepatic gluconeogenesis: effect of L-carnitine

High fructose feeding (60 g/100 g diet) in rodents induces alterations in both glucose and lipid metabolism. The present study was aimed to evaluate whether intraperitoneal carnitine (CA), a transporter of fatty acyl-CoA into the mitochondria, could attenuate derangements in carbohydrate metabolizing enzymes and glucose overproduction in high fructose-diet fed rats. Male Wistar rats of body weight 150-160 g were divided into 4 groups of 6 rats each. Groups 1 and 4 animals received control diet while the groups 2 and 3 rats received high fructose-diet. Groups 3 and 4 animals were treated with CA (300 mg/Kg body weight/day, i.p.) for 30 days. At the end of the experimental period, levels of carnitine, glucose, insulin, lactate, pyruvate, glycerol, triglycerides and free fatty acids in plasma were determined. The activities of carbohydrate metabolizing enzymes and glycogen content in liver and muscle were assayed. Hepatocytes isolated from liver were studied for the gluconeogenic activity in the presence of substrates such as pyruvate, lactate, glycerol, fructose and alanine. Fructose-diet fed animals showed alterations in glucose metabolizing enzymes, increased circulating levels of gluconeogenic substrates and depletion of glycogen in liver and muscle. There was increased glucose output from hepatocytes of animals fed fructose-diet alone with all the gluconeogenic substrates. The abnormalities associated with fructose feeding such as increased gluconeogenesis, reduced glycogen content and other parameters were brought back to near normal levels by CA. Hepatocytes from these animals showed significant inhibition of glucose production from pyruvate (74.3%), lactate (65.4%), glycerol (69.6%), fructose (56.2%) and alanine (63.6%) as compared to CA untreated fructose-fed animals. The benefits observed could be attributed to the effect of CA on fatty acyl-CoA transport.