scholarly journals The Role of Lactic Acid Accumulation in Muscle Fatigue of Two Species of Anurans, Xenopus Laevis and Rana Pipiens

1979 ◽  
Vol 82 (1) ◽  
pp. 35-51
Author(s):  
ROBERT W. PUTNAM
Keyword(s):  
Lactic Acid ◽  
Control Value ◽  
Hindlimb Muscles ◽  
Lactic Acid Content ◽  
Acid Accumulation ◽  
Intense Activity ◽  
Gastrocnemius Muscles ◽  
Glycogen Stores

Fatigue produced a marked increase in the lactic acid content of hindlimb muscles, the blood, and the whole animal. After 15 min of rest there was little decline of lactic acid levels but the animals could be stimulated into about 3 min of intense activity. This re-fatigue produced a further increase in lactic acid levels. Gastrocnemius muscles removed from fatigued frogs and stimulated in vitro were able to generate initial tensions similar to those in control muscles; total tension was about a third of the control value. In vitro stimulation of these muscles from fatigued frogs led to additional accumulation of lactic acid. Fatigue produced little decrease in the glycogen content of muscles in X. laevis but a marked decrease in R. pipiens. Considerable glycogen stores remained even in the muscles of re-fatigued animals. These data show that accumulation of lactic acid in muscle or blood, depletion of glycogen in muscle, or change in blood pH cannot account for fatigue in these species. Possible other causes of fatigue are discussed.

Evidence against a major role of plasmalogens in the resistance of astrocytes in lactic acid-induced oxidative stress in vitro

2001 ◽  
Vol 74 (11) ◽  
pp. 695-701 ◽  
Author(s):  
Bernard Fauconneau ◽  
Sabrina Stadelmann-Ingrand ◽  
Sylvie Favrelière ◽  
Julien Baudouin ◽  
Laurent Renaud ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Lactic Acid

Role of calcium and calmodulin in release of kallikrein and tonin from rat submandibular gland

1986 ◽  
Vol 250 (3) ◽  
pp. C480-C485 ◽  
Author(s):  
S. R. Maitra ◽  
O. A. Carretero ◽  
S. W. Smith ◽  
S. F. Rabito
Keyword(s):  
Submandibular Gland ◽  
Incubation Medium ◽  
High Concentration ◽  
Calcium Blockers ◽  
Control Value ◽  
Voltage Dependent ◽  
Voltage Dependent Calcium Channels ◽  
Intracellular Mediators

We investigated the role of calcium and calmodulin as intracellular mediators of kallikrein and tonin release induced by norepinephrine (NE). We studied the secretion rate of kallikrein and tonin from submandibular gland of rat in response to NE in the presence or absence of calcium, two calcium blockers, and four different calmodulin antagonists. Submandibular gland slices were incubated in vitro, and glandular kallikrein and tonin secreted into the incubation medium were determined by direct radioimmunoassays and expressed as nanograms per minute per milligram tissue. NE (10(-5) and 10(-4) M) increased the kallikrein secretion from the control value of 8.2 +/- 2.6 to 134.9 +/- 41.4 (P less than 0.05) and to 191.2 +/- 62.7 (P less than 0.05), and the release of tonin from a basal rate of 3.5 +/- 0.6 to 51.5 +/- 9.1 (P less than 0.05) and to 64.4 +/- 13.7 (P less than 0.05). The deletion of calcium and addition of EGTA into the incubation medium significantly attenuated the secretion of kallikrein and tonin induced by NE. Nifedipine, at concentrations which inhibit voltage-dependent calcium channels, did not affect the release of kallikrein and tonin, and only a high concentration (10(-4) M) reduced the release. TMB-8, a blocker of intracellular calcium, had no effect either. Phenothiazines, triflupromazine (10(-6) M) and trifluoperazine (10(-4) M), decreased significantly the kallikrein release elicited by 10(-5) M NE.(ABSTRACT TRUNCATED AT 250 WORDS)

The effect of wilting on butyric acid fermentation in silage.

1958 ◽  
Vol 6 (3) ◽  
pp. 204-210 ◽  
Author(s):  
G.W. Wieringa
Keyword(s):  
Lactic Acid ◽  
Osmotic Pressure ◽  
Butyric Acid ◽  
Ion Concentration ◽  
Acid Fermentation ◽  
Silage Fermentation ◽  
Lactic Acid Content ◽  
Vitro Development ◽  
Butyric Acid Fermentation

A comparatively slight increase in environmental osmotic pressure inhibited the in vitro development of butyric-acid bacteria [Clostridium spp.], especially with increasing H-ion concentration. Sub-lethal concentrations of salt (NaCl, KCl, Na2SO4) and/or H-ions retarded the start of clostridial development and reduced the quantity of butyric acid produced. In wilted grass silage it was shown that osmotic pressure plays a considerable part in repressing butyric-acid fermentation in the initial stages of silage fermentation. Low temperature (< 20-25 degrees C.), low pH (< 4.2), high lactic-acid content and high osmotic pressure were more harmful to clostridia than to lactic-acid bacteria.-R.B. (Abstract retrieved from CAB Abstracts by CABI’s permission)

scholarly journals Lactobacillus casei-fermented milk as an inhibitor on selected foodborne pathogens

2022 ◽  
Vol 78 (03) ◽  
pp. 6627-2022
Author(s):  
BAHAR ONARAN ACAR ◽  
NAZLI KANCA ◽  
RABİA ALBAYRAK DELİALİOĞLU
Keyword(s):  
Staphylococcus Aureus ◽  
Lactic Acid ◽  
Foodborne Pathogens ◽  
Lactobacillus Casei ◽  
Methicillin Resistant Staphylococcus Aureus ◽  
Fermented Milk ◽  
Generation Times ◽  
Lactic Acid Content ◽  
Fermentation Period

The aim of this study was to reduce the growth of vanB resistant Enterococcus faecium, vanA resistant Enterococcus faecalis, Staphylococcus aureus ATCC 43300 and methicillin-resistant Staphylococcus aureus- MRSA ATCC 25923, which are foodborne pathogens that cause the death of a significant number of people every year, by the presence of Lactobacillus casei. For this purpose, the development of pathogens (104 and 106 log cfu/ml) in milk fermented with L. casei (106 log cfu/ml) was followed under in vitro conditions for 72 hours. Moreover, the generation times of each pathogen and the lactic acid content of fermented milk were determined. It was determined that the development of all pathogens could be suppressed by the presence of L. casei considering the change in generation times and the number of pathogens during the 72 hour fermentation period. This effect was greater in samples containing 104 log cfu/ml pathogen compared to samples containing 106 log cfu/ml.

scholarly journals Lactic acid in mammalian cardiac muscle. —Part I. The stimulation maximum

1925 ◽  
Vol 99 (694) ◽  
pp. 8-20 ◽  
Keyword(s):  
Skeletal Muscle ◽  
Lactic Acid ◽  
Acid Content ◽  
Skeletal Muscles ◽  
Recovery Process ◽  
Muscular Contraction ◽  
Energy Output ◽  
Lactic Acid Content ◽  
Future Supply

The earlier work of Fletcher and Hopkins (1), and the more recent researches of A. V. Hill (2), Meyerhof (3) and their collaborators on the role of lactic acid in muscular contraction, have shown that oxygen is not required for the production of lactic acid, but only for its removal during the recovery process. This fact, coupled with the ability of a skeletal muscle to respond to stimulation until its lactic acid content is many times the resting value, enables the skeletal muscle to draw on its future supply of oxygen and to go into “oxygen debt.” The question naturally arises, are these facts also true of the heart muscle? Can the heart respond to stimulation when it has accumulated as large a concentration of lactic acid as is found in the skeletal muscle? In other words, How does the stimulation maximum of lactic acid of the heart compare with that of the skeletal muscle? A priori certain differences might be expected in view of the differences in the activity and nutrition of cardiac and skeletal muscles. In the first place the heart is not called upon to increase its energy output to anything like the extent of the skeletal muscle; nor does the heart have any long periods of comparative rest. It is always active and is contracting roughly one-third of the time. In addition the heart is provided with a very efficient circulation and has the first call on the oxygenated blood. For these reasons there seems to be no apparent need for the heart to have the ability of accumulating lactic acid to the same extent as the skeletal muscle; indeed, in view of the necessity for its constant activity, it would seem dangerous for it not to possess a mechanism by which the removal of lactic acid keeps pace with its production.

Lactate and glucose metabolism in mouse (Mus musculus) and reptile (Anolis carolinensis) skeletal muscle

1993 ◽  
Vol 264 (3) ◽  
pp. R487-R491 ◽  
Author(s):  
S. J. Wickler ◽  
T. T. Gleeson
Keyword(s):  
Skeletal Muscle ◽  
Anaerobic Metabolism ◽  
Muscle Metabolism ◽  
Anolis Carolinensis ◽  
Oxidation Rates ◽  
Hindlimb Muscles ◽  
Metabolic Scope ◽  
The Subject ◽  
Glycogen Stores

The reliance on anaerobic metabolism during exercise in lizards has been the subject of a growing body of literature in activity metabolism. Prior studies have demonstrated that lizards rely more on postexercise lactate to regenerate depleted glycogen stores than do many mammals. These studies prompted an in vitro comparison between the metabolic mechanisms for the handling of lactate and glucose in the muscles of a small mammal and lizard. Hindlimb muscles of Mus and Anolis were stimulated to fatigue and then incubated in the presence of 15 mM lactate and either 5.5 (mice) or 8.5 (anoles) mM glucose. Oxidation rates of lactate and glucose were seven to eight times higher in mice. Both species oxidized more lactate than glucose (8 to 9 times). However, anole muscle showed a preference for lactate as a substrate for glycogenesis, incorporating 1.5 times as much lactate (expressed in glucose equivalents) as glucose. In contradistinction, mice incorporated 2.8 times as much glucose into glycogen as lactate. The quantitative differences in metabolic scope of mammals and reptiles are accompanied by fundamental differences in the capacity and patterns of skeletal muscle metabolism of lactate and glucose.

Glycogen replenishment following exercise: effects of denervation and tenotomy

1975 ◽  
Vol 38 (6) ◽  
pp. 961-964 ◽  
Author(s):  
R. A. Ratliff ◽  
D. R. Lamb
Keyword(s):  
Nerve Impulse ◽  
Neural Tissue ◽  
Exhaustive Exercise ◽  
Synthetase Activity ◽  
Glycogen Synthetase ◽  
Denervated Muscles ◽  
Gastrocnemius Muscles ◽  
Glycogen Stores ◽  
Nerve Impulse Conduction

To examine the role of the nervous system in the rapid replenishment of muscle glycogen that occurs after exhaustive exercise, glycogen stores and glycogen synthetase activity of normal gastrocnemius muscles of untrained and trained guinea pigs were compared to glycogen and synthetase activity of trained gastrocnemius muscles that were denervated or tenotomized immediately after exhaustive exercise and then allowed to recover for 48 h. The trained tenotomized muscles, but not the denervated muscles, had significantly (P smaller than 0.05) less glycogen than the trained normal muscles. These results suggest that neither nerve impulse conduction nor tropic substances contained in neural tissue proximal to the site of denervation mediate glycogen replenishment after exercise. The active, glucose 6-phosphate independent (I) form of glycogen synthetase activity was reduced by both denervation and tenotomy at 48 h after exercise with no significant (P greater than 0.05) differences detected for the total of I and D (glucose 6-phosphate dependent) synthetase activity. Synthetase I relative to total synthetase activity was similar in trained and untrained normal muscles, both of which had significantly (P smaller than 0.05) greater relative I activities than denervated or tenotomized muscles. These synthetase data show that elevated glycogen stores following recovery from exercise may be observed in the absence of increased levels of glycogen synthetase activity.

Tyrosine phosphorylation in contraction of opossum esophageal longitudinal muscle in response to SNP

1997 ◽  
Vol 273 (1) ◽  
pp. G247-G252 ◽  
Author(s):  
I. Hirano ◽  
R. Kakkar ◽  
J. K. Saha ◽  
P. T. Szymanski ◽  
R. K. Goyal
Keyword(s):  
Signal Transduction ◽  
Tyrosine Phosphorylation ◽  
Longitudinal Muscle ◽  
Signal Transduction Pathway ◽  
Isometric Contractions ◽  
Muscarinic Agonist ◽  
Transduction Pathway ◽  
Control Value

Sodium nitroprusside (SNP) has been shown to elicit a guanosine 3',5'-cyclic monophosphate (cGMP)-mediated, indomethacin-sensitive contraction of the opossum esophageal longitudinal muscle. We examined the role of tyrosine phosphorylation in the signal transduction pathway of contractions induced by SNP and cGMP in longitudinal muscle strips in vitro. Force of isometric contractions was expressed as the percentage of responses to KCl (73 mM). SNP (100 microM)-induced contractions were 75 +/- 5% before and 3 +/- 2% after 50 microM genistein (P < 0.005) and 86 +/- 16% before and 0 +/- 0% after 50 microM tyrphostin B46. Contractions in response to 8-bromo-cGMP (8-BrcGMP; 1 mM) were 74 +/- 15% before and 3 +/- 2% after genistein (P < 0.01) and 63 +/- 15% before and 18 +/- 4% after tyrphostin B46 (P < 0.05). In contrast, KCl-induced contractions were 82 +/- 8% and 96 +/- 9% of the control value after genistein and tyrphostin B46 treatments, respectively (P > 0.05 for both). Carbachol contractions were partially suppressed by genistein (106 +/- 8% vs. 79 +/- 8%; P < 0.05) but unaffected by tyrphostin B46 (114 +/- 10% vs. 107 +/- 12%; P > 0.05). Western blot analysis revealed a 116-kDa phosphotyrosine protein in the control muscle strips. The level of this protein was increased to 206 +/- 15% of control after SNP treatment. Both genistein and tyrphostin B46 blocked this increase. These studies show that contractions of the esophageal longitudinal muscle induced by SNP and cGMP utilize a signal transduction pathway different from that used by the depolarizing agent KCl and the muscarinic agonist carbachol. Contractions induced by SNP and cGMP involve tyrosine phosphorylation of a protein, possibly identified as a 116-kDa protein, as a key step in the signaling pathway.

scholarly journals PSVIII-23 Effects of different growth height on the yield, chemical composition, silage fermentation profile, in vitro and in situ digestibility of Broussonetia papyrifera

2020 ◽  
Vol 98 (Supplement_4) ◽  
pp. 325-327
Author(s):  
YangYi Hao ◽  
Shuai Huang ◽  
Jun Zhang ◽  
Yue Gong ◽  
Gaokun Liu ◽  
...  
Keyword(s):  
Lactic Acid ◽  
Dry Matter ◽  
Broussonetia Papyrifera ◽  
Silage Fermentation ◽  
Whole Plant ◽  
Lactic Acid Content ◽  
Fermentation Profile ◽  
Different Parts

Abstract Broussonetia papyrifera (BP) is a woody roughage source with high protein content. The experiment was conducted to explore the effects of different growth height (GH) on the BP yield, chemical composition, silage fermentation profile, as well as ruminants in vitro and in situ digestibility of different parts of BP. The three different harvested GH of BP were 0.8, 1.2, and 1.6 m, respectively. Samples from leaf, stem, and whole plant of BP were collected (each one has three replicates), making silage, and detected the nutritional composition of them. The results were analyzed by one-way analysis of variance with Duncan’s multiple comparisons. Fresh weight increased with the GH increased (P &lt; 0.05). No significant difference was observed in dry matter (DM) and crude protein (CP) yield of leaf, and CP yield of whole plant between 1.2 to 1.6 m GH (P &gt; 0.05). With the increase of GH, neutral detergent fiber (NDF) of BP increased, while CP content decreased (P &lt; 0.05). Stem had the highest NDF and acid detergent fiber (ADF) content, and the lowest CP content and buffer capacity. The BP silage fermentation quality was deteriorated (lactic acid content decreased and pH values increased) with GH increased. For the different parts of BP, leaf silage had the highest pH and stem silage had the highest lactic acid content (P &lt; 0.05). The leaf and its silage had the highest in vitro dry matter digestibility and gas production compared to others. The BP in situ digestibility were corresponded with in vitro results. DM, CP, NDF, and ADF effective digestibility rates of whole plant with 1.2 m GH were 439.6, 455.1, 412.9, and 381.3 g/kg, respectively. In conclusion, the BP nutritional quality decreased with GH increased and it could be used as a potential feedstuff for ruminants.

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