Lysine Α-ketoglutarate Reductase Research Articles

Effects of Dietary Lysine Level on Growth Performance and Protein Metabolism in Juvenile Leopard Coral Grouper (Plectropomus leopardus).

An 8-week feeding trial was conducted to evaluate the effects of dietary lysine level on growth performance and protein metabolism of juvenile leopard coral grouper (Plectropomus leopardus) and thereby obtained the optimal dietary lysine requirement of P. leopardus. Six isoproteic and isolipidic experimental diets were formulated to contain 1.10%, 1.69%, 2.30%, 3.08%, 3.56%, and 4.36% lysine of diets, respectively. Each diet was assigned at random to triplicate groups of 25 juveniles (initial mean weight is 10.57 g) per tank in a flow-through mariculture system maintained at 27-30°C. Dietary inclusion of 2.30-3.08% lysine improved the weight gain rate (WGR) and specific growth rate and decreased the feed conversion ratio (FCR) of juveniles (P < 0.05). The intestinal digestive enzyme (trypsin, amylase, and lipase) activities were overall enhanced by dietary inclusion of 3.08-3.56% lysine (P < 0.05). The mammalian target of rapamycin (mTOR) signaling pathway was activated in fish fed diets with 1.69-2.30% lysine by upregulating the relative expression levels of hepatic TOR and S6K1 (p70 ribosomal protein S6 kinase 1) but downregulating the relative expression level of hepatic 4E-BP2 (eIF4E-binding protein 2). Conversely, the amino acid response signaling pathway was inhibited in fish fed diet with 2.30% lysine by downregulating the relative expression levels of hepatic GCN2 (general control nondepressible 2), ATF3 (activating transcription factor 3), ATF4a (activating transcription factor 4a), and ATF4b (activating transcription factor 4b). Additionally, dietary 1.69-3.08% lysine enhanced the plasma total protein level and hepatic lysine α-ketoglutarate reductase activity but depressed the blood urea nitrogen level and hepatic adenosine monophosphate deaminase activity (P < 0.05). Moreover, dietary 3.08% lysine increased the contents of whole-body crude protein and total amino acids, while 1.69%-4.36% lysine depressed the whole-body lipid content (P < 0.05). These results indicated that optimal dietary lysine increased the digestive enzyme activities, promoted protein synthesis but depressed protein degradation, and thereby improved the growth performance of P. leopardus. Based on the second-order polynomial model, the optimal lysine requirement of juvenile P. leopardus for WGR, FCR, and lysine deposition was 2.60%-2.97% of diets (4.91%-5.60% of dietary protein).

The Metabolite Saccharopine Impairs Neuronal Development by Inhibiting the Neurotrophic Function of Glucose-6-Phosphate Isomerase.

Mutations in the Aminoadipate-Semialdehyde Synthase (AASS) gene encoding α-aminoadipic semialdehyde synthase lead to hyperlysinemia-I, a benign metabolic variant without clinical significance, and hyperlysinemia-II with developmental delay and intellectual disability. Although both forms of hyperlysinemia display biochemical phenotypes of questionable clinical significance, an association between neurologic disorder and a pronounced biochemical abnormality remains a challenging clinical question. Here, we report that Aass mutant male and female mice carrying the R65Q mutation in α-ketoglutarate reductase (LKR) domain have an elevated cerebral lysine level and a normal brain development, whereas the Aass mutant mice carrying the G489E mutation in saccharopine dehydrogenase (SDH) domain exhibit elevations of both cerebral lysine and saccharopine levels and a smaller brain with defective neuronal development. Mechanistically, the accumulated saccharopine, but not lysine, leads to impaired neuronal development by inhibiting the neurotrophic effect of glucose-6-phosphate isomerase (GPI). While extracellular supplementation of GPI restores defective neuronal development caused by G498E mutation in SDH of Aass. Altogether, our findings not only unravel the requirement for saccharopine degradation in neuronal development, but also provide the mechanistic insights for understanding the neurometabolic disorder of hyperlysinemia-II.SIGNIFICANCE STATEMENT The association between neurologic disorder and a pronounced biochemical abnormality in hyperlysinemia remains a challenging clinical question. Here, we report that mice carrying the R65Q mutation in lysine α-ketoglutarate reductase (LKR) domain of aminoadipate-semialdehyde synthase (AASS) have an elevated cerebral lysine levels and a normal brain development, whereas those carrying the G489E mutation in saccharopine dehydrogenase (SDH) domain of AASS exhibit an elevation of both cerebral lysine and saccharopine and a small brain with defective neuronal development. Furthermore, saccharopine impairs neuronal development by inhibiting the neurotrophic effect of glucose-6-phosphate isomerase (GPI). These findings demonstrate saccharopine degradation is essential for neuronal development.

Effect of dietary lysine and genetics on growth and indices of lysine catabolism in rainbow trout (Oncorhynchus mykiss)

The level of the essential amino acid lysine is of concern in trout feed. The objective of this study was to investigate the response of different families of fish to lysine-deficient (LD) versus lysine-adequate (LA) soy protein-containing diets. For each treatment combination, there were five replicates. As expected, feed efficiency (p .05) of diet on hepatic lysine α-ketoglutarate reductase (LKR) activity, LKR mRNA abundance or lysine oxidation. There was a family effect on feed efficiency (p < .0001), TGC (p < .0001) and condition factor (p < .05) and there was a trend for differences in oxygen consumption (p < .07) across families while consuming the LD diet; however, there was no effect on ammonia excretion, HSI, lipid content, efficiency of nitrogen or lysine retention or indices of lysine catabolism. One family, in particular, had more favourable feed efficiency and thermal growth coefficient when fed the LD diet, indicating that it may possess an enhanced genetic potential for performance when consuming LD, soybean meal-containing diets.

Lysine metabolism in antisense C-hordein barley grains

The grain proteins of barley are deficient in lysine and threonine due to their low concentrations in the major storage protein class, the hordeins, especially in the C-hordein subgroup. Previously produced antisense C-hordein transgenic barley lines have an improved amino acid composition, with increased lysine, methionine and threonine contents. The objective of the study was to investigate the possible changes in the regulation of key enzymes of the aspartate metabolic pathway and the contents of aspartate-derived amino acids in the nontransgenic line (Hordeum vulgare L. cv. Golden Promise) and five antisense C-hordein transgenic barley lines. Considering the amounts of soluble and protein-bound aspartate-derived amino acids together with the analysis of key enzymes of aspartate metabolic pathway, we suggest that the C-hordein suppression did not only alter the metabolism of at least one aspartate-derived amino acid (threonine), but major changes were also detected in the metabolism of lysine and methionine. Modifications in the activities and regulation of aspartate kinase, dihydrodipicolinate synthase and homoserine dehydrogenase were observed in most transgenic lines. Furthermore the activities of lysine α-ketoglutarate reductase and saccharopine dehydrogenase were also altered, although the extent varied among the transgenic lines.

Regulation of free glutamate content in meat by dietary lysine in broilers.

Regulation of taste is important for improving meat quality and glutamate (Glu) is one of the important taste-active components in meat. Here, the effects of dietary lysine (Lys) content on taste-active components in meat, especially free Glu, were investigated. Fourteen-day-old broiler chicks (Gallus gallus) were fed on diets containing 100% or 150% of the recommended Lys content for 10 days. Concentrations of free amino acids in plasma, muscle and liver were measured. The levels of messenger RNAs (mRNAs) for enzymes related to Glu metabolism were determined in muscle and liver. The concentration of muscle metabolites was also determined. The free Glu content in muscle of chicks fed the Lys150% diet was increased by 44.0% compared with that in chicks fed the Lys100% diet (P < 0.01). The mRNA level of lysine α-ketoglutarate reductase, which is involved in Lys degradation and Glu production, was significantly increased (P < 0.05) in the Lys150% group. Metabolome analysis showed that the Lys degradation products, muscular saccharopine, pipecolic acid and α-aminoadipic acid, were increased in the Lys150% group. Our results suggest that free Glu content in muscle is regulated by Lys degradation. These results suggest that a short-term feeding of high-Lys diet could improve the taste of meat.

Effect of dietary lysine on hepatic lysine catabolism in broilers ,

Lysine is frequently a first- or second-limiting amino acid in poultry diets. Improving the efficiency of lysine use for protein synthesis would effectively lower the lysine requirement and decrease feed costs. Understanding how lysine is degraded and how the degradation is regulated would identify potential molecular targets for interventions to decrease lysine degradation. To better understand lysine degradation in poultry, 3 experiments were conducted. In experiment 1, one-day-old chicks were fed 1.07, 1.25, 1.73, or 3.28% dietary lysine for 2 wk. In experiments 2 and 3, fourteen-day-old chicks were fed 1.07 or 1.25% dietary lysine for 2 wk. Measures of liver lysine catabolism including lysine α-ketoglutarate reductase (LKR) and lysine oxidation (LOX) were assessed. The α-aminoadipate δ-semialdehyde synthase (AASS) is a bifunctional enzyme composed of both LKR and saccharopine dehydrogenase activities, and the relative abundance of this protein and mRNA were likewise assessed. Moreover, potential alternative pathways of lysine catabolism that depend on l-amino acid oxidase (AAOX) and on lysyl oxidase (LYLOX) were considered. In experiment 1, chicks fed lysine-deficient diets had decreased (P < 0.05) LKR activities compared with chicks fed at or above the requirement. However, the lowered LKR activities were not associated with a decreased (P > 0.05) LOX as measured in vitro. In experiments 2 and 3, chicks 28 d of age did not decrease LKR activity (P > 0.05) in response to a lysine-deficient diet. No changes in AASS protein abundance or mRNA were detected. Likewise, no differences in the mRNA abundances of AAOX or LYLOX were detected. The activity of AAOX did increase (P < 0.05) in birds fed a lysine-adequate diets compared with those fed a lysine-deficient diet. Based on kinetic parameters and assumed concentrations, AAOX could account for about 20% of liver lysine oxidation in avians.

Tissue distribution of indices of lysine catabolism in growing swine1

The primary pathway of lysine degradation in pigs presumably depends on the bifunctional protein α-aminoadipate δ-semialdehyde synthase (AASS), which contains lysine α-ketoglutarate reductase (LKR) and saccharopine dehydrogenase (SDH) activities. In liver, AASS is restricted to the mitochondrial matrix and lysine is presumptively transported through the plasma membrane by a cationic AA transporter (CAT1/2) and through the inner mitochondrial membrane by 1 or both mitochondrial ornithine transporters (ORC-1/ORC-2). Lysyl oxidase (LO) may represent an alternative pathway of lysine oxidation. The objective of this experiment was to analyze the distribution of indices of lysine catabolism in various pig tissues. We assessed LKR, SDH, and LO activities, lysine oxidation, mRNA abundance of LKR, CAT1/2, and ORC1/2, and AASS protein abundance (via SDH antibody) in liver, heart, kidney medulla and cortex, triceps, longissimus, whole intestine, enterocytes, and intestine stripped of enterocytes in 10 growing pigs, weighing ∼25 kg. The LKR activity differed across tissues (P<0.001) and was greatest in liver, intestine, and kidney samples, and LKR mRNA abundance (P<0.001) was greatest in liver; although, LKR activity and mRNA abundance were detected in all other tissues. Activity of SDH (P<0.001) and SDH mRNA abundance (P<0.001) were affected by tissue and were greatest in liver compared with all other tissues analyzed. The AASS protein abundance (P<0.001) was greatest in whole intestine and liver. Activity of LO (P<0.0001) was greatest in muscle samples. The abundance of ORC-1 (P<0.001) and ORC-2 mRNA (P<0.001) differed among tissues, and ORC-1 was greatest in liver, kidney, and intestinal preparations, and ORC-2 mRNA abundance was greatest in liver and intestine. Interestingly, LKR activity was correlated with ORC-1 (r=0.32, P<0.05) and ORC-2 (r=0.41, P<0.05) expression. The expression of CAT-1 was uniform in all tissues, whereas CAT-2 (P<0.01) was greatest in liver. In conclusion, these data indicate that extra-hepatic tissues contribute to lysine catabolism as do enzymes other than LKR.

Lysine α-ketoglutarate reductase, but not saccharopine dehydrogenase, is subject to substrate inhibition in pig liver

The activity of lysine α-ketoglutarate reductase (LKR), the initial enzyme in the principal pathway of lysine catabolism, is a primary determinant of whole-body lysine status. Past research indicated that LKR activity was predominantly hepatic; recent in vivo data suggest that other tissues can also catabolize lysine. The hypothesis of this investigation was that lysine catabolism takes place in extrahepatic tissues in pigs and that the enzymes involved may be subject to inhibition or activation. Using mitochondria from various tissues of market-age pigs, the activities of LKR and saccharopine dehydrogenase were measured. Liver mitochondria had the highest LKR activity, and the enzyme was subject to substrate inhibition. Mitochondria from the muscle, kidney, heart, and intestinal epithelial cells all had measurable LKR activity. The LKR activity was significantly inhibited by a variety of compounds including saccharopine, α-aminoadipate, α-ketoadipate, 5-hydroxy-l-lysine, and several metals. Oxidation of (14)C-lysine to (14)CO(2) was demonstrated in mitochondria isolated from the liver, muscle, and intestinal epithelial cells. Western blotting confirmed the presence of the α-aminoadipate δ-semialdehyde synthase protein in some extrahepatic tissues. These data show a significant capacity for lysine degradation in these extrahepatic tissues, most notably in cells of the intestine and muscle. These tissues should be considered important contributors to whole-body lysine catabolism.

Regulation of muscular glutamate metabolism by high‐protein diet in broiler chicks

The major taste active component, glutamate (Glu), improves the taste of meat. In this study, we investigated the effect of a short-term high-protein (HCP) diet on the intramuscular free Glu content to improve the taste of meat. Furthermore, we elucidated how the muscle free Glu content was controlled by the HCP diet. Chicks (14 days old) were fed the control diet or HCP diet for 10 days. Plasma and muscle free amino acid concentrations, and activity and messenger RNA (mRNA) expression of muscle enzymes related to Glu metabolism were determined. Muscle free Glu content was increased (P < 0.01) by 51%. Activity and mRNA expression of glutaminase (GA), which is one of the major Glu-related enzymes, were significantly decreased (P < 0.05) in the HCP group because of feedback inhibition. The mRNA expression of lysine α-ketoglutarate reductase (LKR), which is the enzyme involved in lysine (Lys) degradation and Glu production, was significantly increased (P < 0.001) in the HCP group. These results suggest that short-term dietary HCP feeding is an effective treatment for improving the taste of meat. Furthermore, our results suggest that the free Glu content in muscle is regulated by GA and LKR.

Lysine catabolism in pig tissues

The primary pathway of lysine degradation in pigs presumably depends on the bifunctional protein α‐aminoadipate δ‐semialdehyde synthase (AASS) which contains lysine α‐ketoglutarate reductase (LKR) and saccharopine dehydrogenase (SDH) activities. In liver, AASS is restricted to the mitochondrial matrix and lysine is transported, presumably, by one or both mitochondrial ornithine transporters (MOT1/MOT2). Lysyl oxidase (LylOx) may represent a minor pathway of lysine oxidation. We assessed LKR, SDH and LylOx activities, lysine oxidation, mRNA abundance of LKR and MOT1/2 and AASS protein abundance (via SDH antibody) in liver, heart, kidney medulla and cortex, enterocytes, triceps and longissimus. In growing pigs (n=5), tissues oxidized lysine at varying rates. LKR activity was highest in liver (P&lt;0.05). LKR mRNA abundance in liver was 6 to 130‐fold greater than other tissues (P&lt;0.05). No differences in SDH activity across tissues were detected. No AASS protein could be detected in muscle. LylOx activity was highest in muscle. MOT1 and 2 were detected in every tissue, although no differences were detected as a function of tissue; interestingly there was a significant correlation between LKR activity and MOT1 mRNA abundance (P&lt;0.05, R2= 0.48). These data indicate that extra‐hepatic tissues contribute to lysine oxidation as do enzymes other than LKR. (Support; HATCH WVA 470)

α-Aminoadipate δ-Semialdehyde Synthase mRNA Knockdown Reduces the Lysine Requirement of a Mouse Hepatic Cell Line

α-Aminoadipate δ-semialdehyde synthase (AASS) is the bifunctional enzyme containing the lysine α-ketoglutarate reductase (LKR) and saccharopine dehydrogenase activities responsible for the first 2 steps in the irreversible catabolism of lysine. A rare disease in humans, familial hyperlysinemia, can be caused by very low LKR activity and, as expected, reduces the lysine “requirement” of the individual. This concept was applied to a murine hepatic cell line (ATCC, FL83B) utilizing RNA interference (RNAi) to achieve AASS mRNA knockdown. Cells were antibiotic selected for stable transfection of 2 plasmids that express different short hairpin RNA sequences for AASS knockdown. Compared with the wild-type cell line, AASS mRNA abundance was reduced 79.0 ± 6.4% (P < 0.05), resulting in a 29.8 ± 5.2% (P < 0.05) reduction in AASS protein abundance, 41.3 ± 10.0% (P < 0.05) less LKR activity, and a reduction in lysine oxidation by 50.7 ± 11.8%. To determine the effect of AASS knockdown on the lysine requirement, cells were grown in media containing 12.5, 25.0, 50.0, 100, or 200 μmol/L lysine. Using a segmented model approach for growth rate analysis, the lysine requirement of the cell line with AASS silencing was 43.4 ± 1.7 μmol/L, ∼26% lower (P < 0.05), than the lysine requirement of the wild-type cell line. These results indicate AASS knockdown decreases the lysine requirement of the cell via a reduction of lysine catabolism through the saccharopine pathway, providing the initial proof in principle that RNAi can be used to reduce the nutrient requirement of a system.

>Unique Aspects of Lysine Nutrition and Metabolism

Lysine nutrition is unique among indispensable amino acids in that it can be conserved and can be fed 12 h out of phase (delayed supplement) with the other dietary amino acids. In piglets, high levels (2–6%) of l-lysine added to a 10% protein diet can be tolerated without obvious detrimental effects. In both rat and piglet liver preparations, the first enzyme in the saccharopine-dependent pathway of lysine catabolism, lysine α-ketoglutarate reductase (LKR), is found only in the mitochondrial matrix. For Lys catabolism to occur, Lys must first enter the matrix of the mitochondrion. LKR, saccharopine dehydrogenase, mitochondrial lysine uptake, and lysine oxidation (LOX) all increased >3-fold in rats fed high levels of dietary protein (up to 60%). The activities of mitochondrial Lys uptake and LOX were similar when expressed as mmol/(d · 100 g body weight). Thus, LOX can be a proxy for mitochondrial Lys uptake. Piglet liver LKR and LOX increase 5- to 10-fold when piglets are fed high-protein (50 or 75%) diets. In both the rat and piglet, after adapting to the high protein diet, the activity of LKR is 400–500 times that of LOX, suggesting that Lys uptake by a transporter(s) is rate limiting. Quantitative 24-h dietary infusion studies in piglets revealed that >80% of the Lys infused (4% of the diet) could not be recovered in the urine or body or accounted for by calculated Lys oxidation based on liver activity of LOX. Other pathways and tissues may account for the Lys oxidation in piglets.

α‐Aminoadipate δ‐semialdehyde synthase mRNA knockdown reduces the lysine requirement of a murine hepatic cell line

α-Aminoadipate δ-semialdehyde synthase (AASS) is the bifunctional enzyme containing the lysine α-ketoglutarate reductase (LKR) and saccharopine dehydrogenase activities responsible for the first tw...

Starvation Induced Alterations in Hepatic Lysine Metabolism in Different Families of Rainbow Trout (Oncorhynchus mykiss)

Lysine is the second limiting amino acid in fish meal based diets, second only to methionine. However, little is known about lysine metabolism in rainbow trout (RBT). Therefore, lysine catabolism by the lysine α-ketoglutarate reductase (LKR) pathway was studied. Additionally, since genetically improved strains could influence fish production, these studies were performed in 4 distinct families of RBT. Two full-sibling families, differing in feed efficiency, were selected from each of 2 strains (A and B) of RBT. Eight fish from each of the 4 families were allotted to individual tanks. Fish were fed until satiation for 5 weeks when four fish within each family were randomly selected for 2 weeks of starvation. After the starvation period, all fish were harvested. Hepatic in-vitro LKR activity and lysine oxidation were measured as was LKR mRNA. No effect of family within strain on LKR activity or lysine oxidation was detected. Strain A exhibited a 55% reduction (p < 0.01) in LKR transcripts compared to strain B pooled across both feeding levels. Within each family, LKR mRNA was decreased (p < 0.01) in starved vs. fed fish. On average, there was a 68% decrease in LKR transcripts for starved fish. LKR activity averaged 104 ± 33 and 150 ± 31 nmol/min*gm liver (p > 0.1) in fed and starved fish, respectively. Lysine oxidation averaged 1.2 ± 0.5 and 2.2 ± 0.4 nmol/min*gm liver (p > 0.1) in fed and starved fish, respectively. LKR transcripts were positively correlated to weight gain (p < 0.01). These data are consistent with multiple modes of LKR regulation in fish.

Lysine α-Ketoglutarate Reductase and Lysine Oxidation Are Distributed in the Extrahepatic Tissues of Chickens ,

In animals, lysine oxidation is thought to occur primarily via the activity of lysine alpha-ketoglutarate reductase (LKR). This activity was reported previously in chicken liver, but no work on the tissue distribution of the enzyme in chickens has been reported. Therefore, LKR activity was assayed in liver, kidney, pancreas, heart, brain, lung, spleen, muscle, and intestinal tissues in chickens as was the in vitro ability of tissue homogenates to oxidize lysine. Additionally, the expression of LKR mRNA was assessed by RT-PCR. We found LKR to be present in all tissues studied by both enzymatic analysis and mRNA abundance. Additionally, all tissues assayed oxidized lysine. The extent of lysine oxidation differed among the tissues, consistent with the different pathways of lysine oxidation in the different tissues. These studies demonstrate that LKR is widely distributed in chicken tissues and that tissues other than liver can contribute to whole-body lysine oxidation.

Mitochondrial Lysine Uptake Limits Hepatic Lysine Oxidation in Rats Fed Diets Containing 5, 20 or 60% Casein

Sixty male Sprague-Dawley rats were randomly allotted to receive diets containing 5, 20 or 60% casein. Rats had access to the diet only during the initial 8 h of the daily 12-h dark period. Hepatic mitochondrial lysine uptake, lysine α-ketoglutarate reductase (LKR) and saccharopine dehydrogenase (SacD) activities, and in vitro lysine oxidation (LOX) were measured 0, 6, 12, 18 and 24 h after the start of the dark period. Diurnal variation of mitochondrial lysine uptake was not detected (P > 0.10) although uptake varied 3-fold over 24 h. Mitochondrial lysine uptake was greater (P < 0.05) for rats fed diets containing 60% casein than for rats fed diets containing 5% casein. Diurnal variation of LKR was detected (P < 0.05) in rats fed diets containing 20 and 60% casein. Diurnal variation of SacD was detected (P < 0.05) in rats fed diets containing 60% casein. Increased casein consumption resulted in increased LKR and SacD activities (4- to 5-fold; P < 0.05). Diurnal variation of LOX was detected in rats fed diets containing 20 and 60% casein (P < 0.05). Increasing the casein concentration in the diet from 5 to 60% resulted in a 7-fold increase in LOX (P < 0.05). To make rate comparisons, LKR and SacD activities and LOX were predicted from a range of substrate concentrations (0.1 to 5.0 mmol/L). Overall, LKR and SacD were 6–107 times that of LOX, suggesting that, in liver, mitochondrial lysine uptake limits LOX.

Recombinant Bovine Somatotropin Decreases Hepatic Amino Acid Catabolism in Female Rats

The effect of recombinant bovine somatotropin (rbST) on hepatic amino acid catabolism in female rats was investigated. Daily injections of rbST for 5 d decreased liver homogenate lysine α-ketoglutarate reductase (EC 1.5.1.8) activity (P < 0.05) and liver homogenate lysine oxidation (P < 0.05) ∼35%. Liver homogenate methionine and valine oxidation were depressed ∼20 (P = 0.13) and 35% (P < 0.05), respectively. These data show a decrease in hepatic capacity to oxidize amino acids in rats administered rbST. Whether depressed liver amino acid degrading enzyme activity plays a role in amino acid oxidation in vivo remains to be evaluated.

Metabolic response of liver lysine α-ketoglutarate reductase activity in rats fed lysine limiting or lysine excessive diets

The effects of feeding isonitrogenous diets (at a restricted ration size), containing limiting or excessive amounts of lysine on various biochemical parameters of rats were investigated. Lysine α-ketoglutarate reductase (LKGR) and citrate synthase (CS) activities, hepatic portal vein (HPV) blood and liver free amino acid concentrations were measured in rats fed the experimental diets for up to 8 days. LKGR and CS activities remained constant in rats adapted to the lysine limiting diet. In contrast, LKGR activity rapidly increased (after 2 days) in rats fed the lysine excess diet and remained at a high level for the remainder of the experiment. The increase in liver LKGR activity in response to the lysine excess diet was associated with significant increases in HPV and liver free lysine concentrations (4.5- and 2-fold, respectively). The significance of these data are discussed with respect to the metabolic response of rats challenged with an increased lysine supply and its effects on free lysine concentrations and liver LKGR activity.

A sensitive isotopic assay for the measurement of lysine α-ketoglutarate reductase in cultured rat hepatocytes

A sensitive isotopic assay for the measurement of lysine α-ketoglutarate reductase in cultured rat hepatocytes

A new case of hyperlysinaemia with saccharopinuria

Journal of Inherited Metabolic DiseaseVolume 9, Issue S2 p. 265-267 Short Communication A new case of hyperlysinaemia with saccharopinuria C. Vianey-Liaud, C. Vianey-Liaud Laboratoire de Biochimie, Hôpital Debrousse, Lyon Cedex 05, 69322 FranceSearch for more papers by this authorM. O. Rolland, M. O. Rolland Laboratoire de Biochimie, Hôpital Debrousse, Lyon Cedex 05, 69322 FranceSearch for more papers by this authorP. Divry, P. Divry Laboratoire de Biochimie, Hôpital Debrousse, Lyon Cedex 05, 69322 FranceSearch for more papers by this authorG. Puthet, G. Puthet Service de Néonatologie, Pavillon J, Hôpital Edouard Herriot, Lyon Cedex 08, 69374 FranceSearch for more papers by this authorM. T. Zabot, M. T. Zabot Laboratoire de Biochimie, Hôpital Debrousse, Lyon Cedex 05, 69322 FranceSearch for more papers by this authorJ. Cotte, J. Cotte Laboratoire de Biochimie, Hôpital Debrousse, Lyon Cedex 05, 69322 FranceSearch for more papers by this author C. Vianey-Liaud, C. Vianey-Liaud Laboratoire de Biochimie, Hôpital Debrousse, Lyon Cedex 05, 69322 FranceSearch for more papers by this authorM. O. Rolland, M. O. Rolland Laboratoire de Biochimie, Hôpital Debrousse, Lyon Cedex 05, 69322 FranceSearch for more papers by this authorP. Divry, P. Divry Laboratoire de Biochimie, Hôpital Debrousse, Lyon Cedex 05, 69322 FranceSearch for more papers by this authorG. Puthet, G. Puthet Service de Néonatologie, Pavillon J, Hôpital Edouard Herriot, Lyon Cedex 08, 69374 FranceSearch for more papers by this authorM. T. Zabot, M. T. Zabot Laboratoire de Biochimie, Hôpital Debrousse, Lyon Cedex 05, 69322 FranceSearch for more papers by this authorJ. Cotte, J. Cotte Laboratoire de Biochimie, Hôpital Debrousse, Lyon Cedex 05, 69322 FranceSearch for more papers by this author First published: 01 June 1986 https://doi.org/10.1007/BF01799724Citations: 1AboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinked InRedditWechat No abstract is available for this article.Citing Literature Volume9, IssueS2June 1986Pages 265-267 RelatedInformation