Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “Pyruvates”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 919 records · Page 51Linked to original sources

Congenital lactic acidosis due to pyruvate carboxylase deficiency: absence of an inhibitor of TPP-ATP phosphoryl transferase.

Two children are described who suffered from episodes of metabolic acidosis and progressive mental and motor deterioration. The patients showed periodic elevation of blood lactate, pyruvate and alanine, which was accompanied by vomiting, hypotonia or convulsions. The concentrations of lactate and pyruvate in cerebrospinal fluid were found to be increased. Liver biopsies revealed a decrease in pyruvate carboxylase activity and normal pyruvate decarboxylase activity. No inhibitor of TPP-ATP phosphoryl transferase was detected in urine from the patients. These findings suggest that congenital lactic acidosis due to pyruvate carboxylase deficiency is probably a different disease entity from Leigh's encephalomyelopathy. A possible mechanism of brain damage caused by a defect in pyruvate carboxylase is postulated.

Acidosis↗

A comparative study of the transport of pyruvate in liver mitochondria from normal and diabetic rats.

A comparative study of the transport of pyruvate in liver mitochondria from normal and diabetic rats has been carried out. The Km for the pyruvate uptake in diabetic, ketotic mitochondria is practically equal to that measured in normal mitochondria, while the Vmax is significantly lower. The lower activity of the pyruvate translocator in diabetic mitochondria compared to normal mitochondria is also shown by swelling experiments as well as by following the rate of pyruvate-supported respiration. Pre-exposure of mitochondria from normal rats to the ketone body acetoacetate and to 2-oxobutyrate results in a decrease of the Km for pyruvate uptake. This effect is impaired in mitochondria from diabetic animals. The results indicate that the activity and the properties of the mitochondrial pyruvate translocator are modified in the diabetic, ketotic condition.

3-Hydroxybutyric Acid↗

Effect of pyruvate on rat heart thiol status during ischemia and hypoxia followed by reperfusion.

Ischemia or hypoxia followed by reperfusion determine a large release of glutathione from isolated and perfused rat heart. The effects of glucose and/or pyruvate administered during ischemia/reperfusion or hypoxia/reperfusion on the release of cytosolic and mitochondrial glutathione are compared. During ischemia, mitochondrial glutathione is released from the mitochondrion to the cytosol forming a unique pool that leaks out to the interstitial space. Reperfusion causes a large release of total glutathione, particularly from cytosol. Total sulfhydryl groups do not undergo modifications after ischemia, while they appear to decrease upon reperfusion. Pyruvate, which protects the heart by inducing a large recovery of the contractile activity after ischemia, markedly prevents the loss of glutathione. Also total sulfhydryl groups of mitochondria do not undergo significant variation upon ischemia and reperfusion in the presence of pyruvate. During hypoxia, in the absence of glucose, glutathione is mainly lost from the cytosol, while the mitochondrial pool appears to be preserved; in hypoxia, at variance with the ischemic conditions, pyruvate does not show any beneficial effect. The action of pyruvate appears to be multifactorial and its effects are discussed by considering its action on the hydrogen peroxide breakdown, protection of pyruvate dehydrogenase, anaerobic production of ATP and diminution of the intracellular concentration of inorganic phosphate.

Animals↗

The importance of porE and porF in the anabolic pyruvate oxidoreductase of Methanococcus maripaludis.

The operon of the anabolic pyruvate oxidoreductase (POR) of Methanococcus maripaludis encodes two genes ( porEF) whose functions are unknown. Because these genes possess sequence similarity to polyferredoxins, they may be electron carriers to the POR. To elucidate whether the methanococcal POR requires PorEF for activity, a deletion mutant, strain JJ150, lacking porEF was constructed. Compared to the wild-type strain JJ1, the mutant grew more slowly in minimal medium and minimal plus acetate medium, and pyruvate-dependent methanogenesis was inhibited. In contrast, the methyl-viologen-dependent pyruvate-oxidation activity of POR, carbon monoxide dehydrogenase, and hydrogenase activities of the mutant were similar to those of the wild-type. Upon genetic complementation of the mutant with porEF in the methanococcal shuttle vector pMEV2+ porEF, growth in minimal medium and pyruvate-dependent methanogenesis were restored to wild-type levels. Complementation with porE alone restored methanogenesis from pyruvate but not growth in minimal medium. Complementation with porF alone partially restored growth but not methanogenesis from pyruvate. Although the specific roles of porE and porF have not been determined, these results suggest that PorEF play important roles in the anabolic POR in vivo even though they are not required for the dye-dependent activity.

Aldehyde Oxidoreductases↗

Regulation of pyruvate oxidation in blowfly flight muscle mitochondria: requirement for ADP.

Blowfly (Phormia regina) flight muscle mitochondria oxidized pyruvate ( + proline) in the presence of either ADP (coupled respiration) or carbonylcyanide-p-trifluoromethoxyphenylhydrazone (FCCP-uncoupled respiration). There was an absolute requirement for ADP (Km = 8.0 microM) when pyruvate oxidation was stimulated by FCCP in the presence of oligomycin. This requirement for ADP was limited to the oxidation of pyruvate; uncoupled alpha-glycerolphosphate oxidation proceeded maximally even in the absence of added ADP. Atractylate inhibited uncoupled pyruvate oxidation whether added before (greater than 99%) or after (95%) initiation of respiration with FCCP. In the presence of FCCP, oligomycin, and limiting concentrations of ADP (less than 110 microM), there was a shutoff in the uptake of oxygen. This inhibition of respiration was completely reversed by the addition of more ADP. Plots of net oxygen uptake as a function of the limiting ADP concentration were linear; the observed ADP/O ratio was 0.22 +/- 0.025. An ADP/O ratio of 0.2 was predicted if phosphorylation occurred only at the succinyl-CoA synthetase step of the tricarboxylate cycle. Experiments performed in the presence of limiting concentrations of ADP, and designed to monitor changes in the mitochondrial content of ADP and ATP, demonstrated that the shutoff in oxygen uptake was not due to the presence of a high intramitochondrial concentration of ATP. Indeed, ATP, added to the medium prior to the addition of FCCP, inhibited uncoupled pyruvate oxidation; the apparent KI was 0.8 mM. These results are consistent with the hypothesis that it is the intramitochondrial ATP/ADP ratio that is one of the controlling factors in determining the rate of flux through the tricarboxylate cycle. Changes in the mitochondrial content of citrate, isocitrate, alpha-ketoglutarate, and malate during uncoupled pyruvate oxidation in the presence of a limiting concentration of ADP were consistent with the hypothesis that the mitochondrial NAD + -linked isocitric dehydrogenase is a major site for such control through the tricarboxylate cycle.

Adenosine Diphosphate↗

Inhibition of glycine oxidation by pyruvate, alpha-ketoglutarate, and branched-chain alpha-keto acids in rat liver mitochondria: presence of interaction between the glycine cleavage system and alpha-keto acid dehydrogenase complexes.

Pyruvate, alpha-ketoglutarate, and branched-chain alpha-keto acids which were transaminated products of valine, leucine, and isoleucine inhibited glycine decarboxylation by rat liver mitochondria. However, glycine synthesis (the reverse reaction of glycine decarboxylation) was stimulated by those alpha-keto acids with the concomitant decarboxylation of alpha-keto acid added in the absence of NADH. Both the decarboxylation and the synthesis of glycine by mitochondrial extract were affected similarly by alpha-ketoglutarate and branched-chain alpha-keto acids in the absence of pyridine nucleotide, but not by pyruvate. This failure of pyruvate to have an effect was due to the lack of pyruvate oxidation activity in the mitochondrial extract employed. It indicated that those alpha-keto acids exerted their effects by providing reducing equivalents to the glycine cleavage system, possibly through lipoamide dehydrogenase, a component shared by the glycine cleavage system and alpha-keto acid dehydrogenase complexes. On the decarboxylation of pyruvate, alpha-ketoglutarate, and branched-chain alpha-keto acids in intact mitochondria, those alpha-keto acids inhibited one another. In similar experiments with mitochondrial extract, decarboxylations of alpha-ketoglutarate and branched-chain alpha-keto acid were inhibited by branched-chain alpha-keto acid and alpha-ketoglutarate, respectively, but not by pyruvate. NADH was unlikely to account for the inhibition. We suggest that the lipoamide dehydrogenase component is an indistinguishable constituent among alpha-keto acid dehydrogenase complexes and the glycine cleavage system in mitochondria in nature, and that lipoamide dehydrogenase-mediated transfer of reducing equivalents might regulate alpha-keto acid oxidation as well as glycine oxidation.

3-Methyl-2-Oxobutanoate Dehydrogenase (Lipoamide)↗

Pigeon liver phosphoprotein phosphatase: an effective activator of pyruvate dehydrogenase in tissue homogenates.

A fluoride-insensitive, non-metal-requiring pyruvate dehydrogenase phosphatase has been purified 730-fold from pigeon liver acetone powder and proven to be a convenient reagent for studies of pyruvate dehydrogenase complex and its activation (phosphorylation) state in brain and other tissues. This phosphatase is a cytoplasmic enzyme (Mr = 80,000), and fits the functional definition of a type 1 phosphoprotein phosphatase. The pigeon liver phosphatase can be used to activate pyruvate dehydrogenase complex in vitro in brain and other crude tissue homogenates. Addition of the cytoplasmic pigeon liver phosphatase to a homogenate from rat or mouse brain frozen in situ activated pyruvate dehydrogenase to levels comparable to that found in ischemic brain. The fluoride insensitivity of this phosphatase was used to develop a convenient technique for stopping the pyruvate dehydrogenase activation state in situ in cultured skin fibroblasts and then fully activating the complex in vitro in 5 min. The use of this phosphatase as a reagent can facilitate the study of pyruvate dehydrogenase activation defects in mammalian tissues including cultured cells in normal and disease states.

Animals↗

Transport of pyruvate and lactate in yeast mitochondria.

Evidence for the existence of mediated transport of pyruvate and lactate in isolated mitochondria of Saccharomyces cerevisiae is presented. 1. The mitochondrial oxidation of pyruvate is specifically inhibited by the monocarboxylic oxoacids alpha-ketoisocaproate and by alpha-cyano-3-hydroxycinnamate, while pyruvate and malate dehydrogenases activities are not inhibited. 2. The stimulation of the mitochondrial oxidations of succinate, alpha-ketoglutarate and citrate by pyruvate are also inhibited by alpha-cyano-3-hydroxycinnamate. 3. The [14C]pyruvate uptake by yeast mitochondria follows saturation kinetics and is completely inhibited by alpha-cyano-3-hydroxycinnamate. 4. Large amplitude passive swellings of mitochondria of the wild type and of cytoplasmic rho- and rho-n mutants are induced by isoosmotic ammonium pyruvate and lactate. These pH-dependent swellings are inhibited by alpha-cyano-3-hydroxycinnamate suggesting that the carrier system is not coded by mitochondrial DNA.

Carboxylic Acids↗

Inhibition of pyruvate transport by fatty acids in isolated cells from rat small intestine.

1. A technique is described for the rapid separation of intestinal epithelial cells from the incubation medium by passage through a silicon-oil layer and collection in acid, in which their soluble constituents are released. 2. The inhibition by fatty acids of pyruvate oxidation is further studied. Measurement of pyruvate transport in epithelial cells at 0 degree C showed that short- and medium-chain fatty acids as well as ricinoleate inhibit this transport. Propionate inhibits pyruvate transport by another mechanism than octanoate. 3. Differences between pyruvate propionate and octanoate transport across the epithelial cell membrane were obtained in efflux studies. These studies revealed that acetate, propionate, butyrate and high concentrations of bicarbonate readily stimulate the efflux of pyruvate, probably by anionic counter-transport. No effects were seen with octanoate and hexanoate. The data obtained in these efflux studies suggest that lipophilicity and the pKa values of the monocarboxylic acids determine the contribution of non-ionic diffusion to overall transport. 4. Saturation kinetics, competitive inhibition by short-chain fatty acids and counter-transport suggest a carrier-mediated transport of pyruvate.

Animals↗

The binding of a fluorescent activator 2-(N-decyl)aminonaphthalene-6-sulfonic acid to pyruvate oxidase.

E. coli pyruvate oxidase (pyruvate:ferricytochrome b1 oxidoreductase, EC 1.2.2.2) is a peripheral membrane flavoenzyme which has been purified to homogeneity. In vivo the oxidase resides on the inner surface of the cytoplasmic membrane and is coupled to the bacterial electron transport chain. In vitro, the purified oxidase requires lipids for full enzymatic activity. Previous studies have characterized the conformational and energetic coupling between the lipid-binding site(s) and the catalytic active site. The affinity of the enzyme for phospholipids and detergents is significantly enhanced when the flavoprotein is in the reduced form, i.e., in the presence of pyruvate and the required cofactor, thiamin pyrophosphate. The lipid-binding studies were hindered due to the complicating factor of the self-association of the substrate-reduced flavoprotein. In this paper, fluorescence techniques are employed to measure the binding of a detergent-like activator to the oxidase. The experiments are performed at much lower protein concentrations than previously employed, so that protein aggregation is not a problem. The chromophore on the activator, 2-(N-decyl)aminonaphthalene-6-sulfonic acid is effective at quenching the pyruvate oxidase intrinsic tryptophan fluorescence. Quenching titrations are used to obtain the binding isotherm. AT DNS concentrations less than 10(-5) M, the results show a larger amount of DNS binding to the reduced flavoprotein than to the oxidized form of the enzyme. This is the concentration range where DNS is an effective activator of the enzyme. This represents a class of binding sites specifically found on pyruvate oxidase and not apparent in other proteins such as lysozyme or aldolase. At the DNS concentration which is optimum for activation approx. 20 molecules of DNS are bound per enzyme tetramer in the absence of the substrate. The pyruvate-reduced form of the enzyme binds about 40--50 molecules of DNS per tetramer. Qualitatively, the results are similar to what was previously found for both sodium dodecyl sulfate and cetyl trimethylammonium bromide. However, in both these cases, the amount of bound detergent was nearly an order of magnitude less than the values obtained using DNS.

Enzyme Activation↗

Inhibition of hepatic propionyl-CoA synthetase activity by organic acids. Reversal of propionate inhibition of pyruvate metabolism.

Intracellular accumulation of propionyl-CoA is associated with impairment of important hepatic metabolic pathways. Since propionate absorbed from the intestine can be converted to propionyl-CoA in the liver, inhibition of propionyl-CoA synthesis from propionate and CoA may provide a strategy for decreasing toxicity from plasma propionate. Therefore, inhibition of propionyl-CoA formation by several organic acids was investigated. In isolated, solubilized mitochondria, octanoate, butyrate, salicylate and p-nitrobenzoate inhibited propionyl-CoA synthesis. Octanoate was the most potent inhibitor of propionyl-CoA synthetase activity and had a Ki of 58 microM. In isolated hepatocytes, octanoate inhibited propionate oxidation in a concentration-dependent manner. Consistent with previous studies, propionate (1.0 mM) inhibited the rates of 14CO2 formation from [1-14C]pyruvate (10 mM) to 55% of the control values in the hepatocyte system. Octanoate (0.8 mM) had no effect on [1-14C]pyruvate oxidation under control conditions, but increased 14CO2 formation from pyruvate to 88% of the control values in the presence of 1.0 mM propionate. Reversal of propionate inhibition of pyruvate oxidation by octanoate was associated with a 44% decrease in hepatocyte propionyl-CoA content. In contrast, while pyruvate oxidation rates were decreased to 53% of control rates in the presence of 10 mM propionylcarnitine, octanoate stimulated pyruvate oxidation under these conditions only to 67% of control levels. In conclusion, mitochondrial propionyl-CoA synthetase activity and hepatocyte propionyl-CoA accumulation can be inhibited by octanoate with consequent decreased propionate oxidation and toxicity in intact hepatocytes. The reversal by octanoate of propionate's inhibition of cellular metabolism may be useful in reducing tissue toxicity from circulating propionate.

Acyl Coenzyme A↗

Effect of exogenous pyruvate on acrylamide neuropathy in rats.

The protective effect of exogenous sodium pyruvate on the distal-proximal progression of experimental acrylamide neuropathy in rats was examined. Incorporation of 2% (w/w) sodium pyruvate powder in the diet of rats receiving subcutaneous injections of an aqueous solution of acrylamide (35 mg/kg/day, 5 days/week) retarded the onset and development of functional, morphological, and biochemical measures of acrylamide neuropathy. Pyruvate supplementation did not alter hexobarbital sleep time or zoxazolamine paralysis time, two in vivo measures of microsomal mixed-function oxidase activity, and the disposition of radioactivity in plasma or sciatic nerve following subcutaneous injection of [14C]acrylamide. Although acrylamide can interfere with energy metabolism at a variety of sites where pyruvate can rescue neurons (axons), the data of this study are consistent with our earlier hypothesis that acrylamide neuropathy may be associated with a glycolytic deficit. The exact site of pyruvate protection is unknown. Exogenous pyruvate is perhaps utilized by axons to circumvent toxin-induced glycolytic inhibition and provide chemical energy for fast axonal transport.

Acrylamide↗

Antioxidant effects of pyruvate in isolated rat hearts.

Sprague-Dawley rat hearts were perfused under constant flow conditions, and a balloon was inserted into the left ventricle to measure heart rate (HR) and left ventricular pressures. Left ventricular generated pressure (LVGP) was calculated as peak systolic minus end diastolic pressure. Three substrate groups, pyruvate (5 mM), glucose (15 mM) and octanoate (0.5 mM), were employed. Oxidative stress was induced by perfusion with tertiary-butyl hydroperoxide (tBHP, 0.35 mM, 12 min) followed by 25 min of perfusion with control buffer. Hearts perfused with pyruvate showed no significant decrease in contractile function following tBHP treatment (HR x LVGP = 17666 +/- 585 mmHg/min, initial: 16414 +/- 2083 post-tBHP treatment). Glucose-perfused hearts had an intermediate decrease in function (19174 +/- 828 mmHg/min, initial; 4379 +/- 2083 post-tBHP), while octanoate-perfused hearts recovered no contractile function. Peak release of LDH was lowest in hearts perfused with pyruvate (115 +/- 17 mU/g wet wt/min), intermediate in glucose-perfused hearts (1575 +/- 380) and highest in octanoate-perfused hearts (3074 +/- 499). Thiobarbituric acid reactive substances (TBARS) were unchanged in hearts perfused with pyruvate (16.2 +/- 5 nmoles/g wet wt), but increased significantly in glucose-perfused hearts (36.1 +/- 1) and in octanoate-perfused hearts (45.5 +/- 9). Total glutathione levels were unchanged in hearts perfused with pyruvate (753 +/- 68 nmoles/g wet wt), but significantly decreased in glucose-perfused hearts (594 +/- 68) and in octanoate-perfused hearts (445 +/- 38) following tBHP-treatment. Pyruvate significantly reduced oxidative injury. In contrast, glucose provided a small reduction in injury while octanoate-perfused hearts had the most severe injury.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗

Stimulation of mitochondrial pyruvate transport in rat renal cortex by phenylephrine.

Phenylephrine effect on liver and kidney cortex mitochondrial pyruvate concentration was investigated. While in liver the alpha 1-adrenergic agent produced a decrease in pyruvate content, a significant increase was observed in kidney, even in the presence of 0.5 mM alpha-cyano-4-hydroxy-cinnamate. These changes were not observed when pyruvate was formed by intramitochondrial transamination of alanine, suggesting a role for the pyruvate transport across mitochondrial membranes in the regulation of mitochondrial pyruvate metabolism in kidney cortex. This was corroborated measuring the phenylephrine effect on pyruvate carboxylation.

Alanine↗

Protection by pyruvate against inhibition of Na+, K(+)-ATPase by a free radical generating system containing t-butylhydroperoxide.

Global tissue damage due to oxygen-derived free radicals has been implicated in several pathological processes including exposure to ionizing radiation, and postischemic reperfusion of the heart or kidney. Recently pyruvate, a hydroperoxide scavenger, has been shown to protect against functional damage during postischemic reperfusion of the heart and in acute renal failure. In the present study, pyruvate was found to protect against inactivation of partially purified guinea pig renal and rat cardiac Na+,K(+)-ATPase which occurred when microsomal membranes were assayed for 1 hr at 37 degrees C (pH 7.5) in the presence of a free radical generating system (FRGS) containing 0.3 mM t-butylhydroperoxide and horseradish peroxidase. The presence of the FRG system inhibited the guinea pig renal Na+,K(+)-ATPase activity by 48.2 +/- 4.8% (N = 10, P < .05) and the presence of 0.2 to 20 mM pyruvate partially protected the Na+,K(+)-ATPase. At 5 mM pyruvate Na+,K(+)-ATPase was inhibited by only 18.8 +/- 2.5% (N = 10, P < .05) but increasing the pyruvate concentration gave no further protection. Equimolar concentrations of glucose, mannitol or lactate were without effect. The protection appeared to require an alpha-keto acid since alpha- but not beta-ketoglutarate was also effective and the mechanism is most probably the scavenging of t-BHO2. The results of the present study therefore support the hypothesis that, if free radical damage to native Na+,K(+)-ATPase does contribute to global tissue injury in certain pathological processes, pyruvate, in addition to being a powerful metabolic effector of recovery, may also protect against oxidative damage.

Animals↗

Pyruvate inhibits clofibrate-induced hepatic peroxisomal proliferation and free radical production in rats.

In an effort to identify the effects of the 3-carbon compound pyruvate on free radical production, we measured hepatic total peroxisomal beta-oxidation and catalase activity and the production of lipofuscin-like products in male Sprague-Dawley rats consuming an adequate diet supplemented with pyruvate, vitamin E, or the peroxisome proliferator and free radical enhancer clofibrate for 22 days (n = 5 in each group). Clofibrate feeding induced hepatomegaly, a fivefold increase in total peroxisomal beta-oxidation activity, and a threefold increase in hepatic lipofuscin-like products (P < .05). Pyruvate but not vitamin E inhibited the increase in liver size by 70% (P < .05). Both pyruvate and vitamin E completely inhibited clofibrate-induced increases in lipofuscin-like products (P < .05). Pyruvate but not clofibrate or vitamin E increased plasma concentrations of the nitric oxide metabolites nitrite and nitrate (P < .05). We conclude that with clofibrate-induced peroxisomal proliferation and free radical production, pyruvate will inhibit peroxisomal proliferation and free radical production, inhibit free radical-induced lipid peroxidation, and enhance metabolism of nitric oxide.

Animals↗

The production of lactate and pyruvate as sensitive indices of altered rat Sertoli cell function in vitro following the addition of various testicular toxicants.

Lactate and pyruvate are hormonally stimulated products of the Sertoli cell, which are essential for germ cell survival. The utility of measuring these products as indices of Sertoli cell function was examined using toxicants targeted to this cell type. Hence, 1,3-dinitrobenzene (1,3-DNB; 10(-6) - 10(-4) M), and mono-(2-ethylhexyl)phthalate (MEHP; 10(-8) - 10(-4) M) were tested in rat Sertoli cell cultures. Both compounds produced significant dose-related increases (maximally three- to fourfold) in lactate concentrations in the culture medium. Only 1,3-DNB produced significant dose-related increases (up to eight- to ninefold) in pyruvate concentrations. All increases occurred within 24 hr of exposure, with the earliest changes occurring within 1-2 hr. The specificity of the responses was examined by comparison with the nontoxic isomers, 1,2 and 1,4-DNB, and the parent compound of MEHP, di-(2-ethylhexyl) phthalate and its inactive metabolite, 2-ethylhexanol. None of these compounds showed significant effects on lactate or pyruvate production. The spermatocyte toxicant, ethylene glycol monomethyl ether (EGME), and its major metabolite, methoxyacetic acid (MAA), were also tested. EGME had no effect on lactate or pyruvate production, and MAA produced a decrease in lactate concentration only at the maximum dose employed (5 mM). These results show that dose-related increases in lactate production were only observed for the two Sertoli cell toxicants, and only for 1,3-DNB in the case of pyruvate production. Inactive isomers, metabolites, and germ cell toxicants did not produce these changes. Thus, lactate (and pyruvate) production by rat Sertoli cell cultures may be a sensitive index of altered function as induced by 1,3-DNB and MEHP.

Acetates↗

Effect of physostigmine on plasma lactate and pyruvate in untrained/trained rats.

Physostigmine (Phy) is metabolized to eseroline, a phenolic compound that appears to alter mitochondrial functions. The effect of Phy on recovery from exercise and on time course of plasma lactate and pyruvate levels following an acute bout of exercise (AE) was examined in untrained and trained (ET) rats. Phy alone elicited significantly higher plasma lactate and pyruvate levels than sedentary control. AE + Phy had a significantly higher plasma lactate and pyruvate levels compared to AE 2 min postadministration. From 5-30 min postexercise, lactate and pyruvate levels did not differ between these two acutely exercised groups. ET + Phy exhibited significantly lower levels of plasma lactate and pyruvate from 5-60 min postexercise compared to ET. The data show that the "additive" effect of Phy on postexercise plasma lactate and pyruvate levels can be attenuated by an enhanced fitness level in these rats.

Animals↗