scholarly journals Aerobic lactate production by mammary tissue

1975 ◽  
Vol 146 (1) ◽  
pp. 273-275 ◽  
Author(s):  
A R Elkin ◽  
N J Kuhn
Keyword(s):  
Glucose Uptake ◽  
Lactate Production ◽  
Mammary Glands ◽  
Mammary Tissue ◽  
Metabolic Derangement ◽  
Intact Tissue ◽  
Lactate Formation ◽  
Normal Feature

Glucose uptake and L-lactate production were measured in cell, slice and intact tissue preparations of mammary glands from late-pregnant and lactating rats. The tissues showed extensive conversion of glucose into lactate in vitro, but not in vivo. Therefore aerobic lactate formation is not a normal feature of mammary tissue, but occurs in vitro as the result of some metabolic derangement.

scholarly journals Rapid inhibition by intragastric triolein of the re-activation of glucose utilization and lipogenesis in the mammary gland during the starved-refed transition in lactating rats. Evidence for a direct effect of oral lipid on mammary tissue

1988 ◽  
Vol 250 (1) ◽  
pp. 269-276 ◽  
Author(s):  
S W Mercer ◽  
D H Williamson
Keyword(s):  
Mammary Gland ◽  
Glucose Uptake ◽  
Time Course ◽  
Glucose Utilization ◽  
Lactate Production ◽  
Dietary Lipid ◽  
Mammary Tissue ◽  
Phosphofructokinase Activity ◽  
Fructose 1,6 Bisphosphate

1. Oral administration of triacylglycerol (triolein) to starved/chow-refed lactating rats suppressed the lipogenic switch-on in the mammary gland in vivo. 2. A time-course study revealed that triolein, administered at 30 min after the onset of refeeding, had no influence on lipogenic rate in the mammary gland between 30 and 60 min, but markedly decreased it between 60 and 90 min. Glucose uptake by the mammary gland (arteriovenous difference) increased by 30 min of refeeding, as did lactate production. Between 30 and 90 min glucose uptake remained high in the control animals, but glucose uptake and net C3-unit uptake were decreased in the triolein-loaded animals by 90 min. 3. Triolein increased [glucose 6-phosphate] in the gland and simultaneously decreased [fructose 1,6-bisphosphate], indicative of a decrease in phosphofructokinase activity. This cross-over occurred at 60 min, i.e. immediately before the inhibition of lipogenesis, and by 90 min had reached ‘starved’ values. 4. Triolein had no effect on plasma [insulin] nor on whole-blood [glucose], [lactate] or [3−hydroxybutyrate]; a small increase in [acetoacetate] was observed. 5. Infusion of the lipoprotein lipase inhibitor, Triton WR1339, abolished the suppression of mammary-gland lipogenesis by triolein and the increase in the [glucose 6-phosphate]/[fructose 1,6-bisphosphate] ratio, suggesting a direct influence of dietary lipid on mammary-gland glucose utilization and phosphofructokinase activity.

scholarly journals 135 REGULATION OF GLUCOSE METABOLISM TO DECREASE LIPID CONTENT OF IN VIRTO-PRODUCED BOVINE EMBRYOS

2005 ◽  
Vol 17 (2) ◽  
pp. 218 ◽  
Author(s):  
J. De La Torre-Sanchez ◽  
D. Gardner ◽  
K. Preis ◽  
G. Seidel Jr
Keyword(s):  
Glucose Metabolism ◽  
Glucose Uptake ◽  
Surface Area ◽  
Lipid Accumulation ◽  
Lactate Production ◽  
Pentose Phosphate ◽  
Developmental Competence ◽  
Metabolic Regulators

Our objective was to improve normality of embryos produced in vitro with regulators of carbohydrate metabolism at doses optimized in earlier experiments. Eight- to 16-cell embryos were produced in vitro in the G1/G2 system (chemically defined sequential medium with recombinant human serum albumin), and then cultured 3 days in G2 containing metabolic regulators as follows: phenazine ethosulfate (PES), 0.3 μM; NaN3, 27 μM; 2,4-dinitrophenol (DNP), 30 μM; and control. The following responses were analyzed by ANOVA in 2 to 4 replicates of 8–12 embryos each: glucose uptake and metabolism (uptake measured by microfluorometry of medium after incubating an embryo 3 h; metabolism measured as 3H2O released after incubating an embryo 3 h in medium containing 5-3H glucose), % of glucose metabolized via the pentose phosphate pathway (PPP rate), lactate production, glycolysis (% of lactate produced from glucose taken up on a molar basis), lipid accumulation (number of >2 μM Sudan Black B positive granules/103 μm2), % live Day 14 embryos recovered from embryos transferred to recipients at Day 7, and average surface area of embryos collected. In vivo-derived embryos were included as a second control for lipid evaluation. PES-treated embryos had higher glucose metabolism (P < 0.05) and lower glucose uptake (P < 0.01) than embryos in NaN3 and tended to have a higher PPP rate (P < 0.11) than controls; however, glycolysis was higher for PES than other treatments (P < 0.01) (Table 1). Lipid accumulation of embryos from PES was markedly lower than any other in vitro treatments (P < 0.01), but higher than in vivo embryos (3.31 ± 2.78 lipid granules) (P < 0.01). NaN3- and DNP-treated embryos both accumulated lipid similar to in vitro controls. No treatment differences were found in developmental competence when Day 7 embryos were transferred to recipients and recovered 1 week later (43 to 54% live embryos recovered), nor were there any significant differences (P > 0.1) in surface area. Embryos exposed to PES at the compaction and post-compaction stages accumulated much less lipid than controls or embryos exposed to other metabolic regulators, making this a very promising treatment. PES oxidizes NADPH; the molecular mechanism of PES appears to involve increased flux of glucose through the PPP while decreasing availability of NADPH for fatty acid synthesis. Table 1. Response of embryos to metabolic regulators

scholarly journals Acute effects of phorbol esters on the protein-synthetic rate and carbohydrate metabolism of normal and mdx mouse muscles

1991 ◽  
Vol 275 (2) ◽  
pp. 477-483 ◽  
Author(s):  
P A MacLennan ◽  
A McArdle ◽  
R H Edwards
Keyword(s):  
Glucose Uptake ◽  
Carbohydrate Metabolism ◽  
Phorbol Esters ◽  
Glycogen Synthesis ◽  
Lactate Production ◽  
Kinetic Studies ◽  
Mdx Mouse ◽  
Mdx Mice

1. mdx mice do not express dystrophin, the product of the gene which is defective in Duchenne and Becker muscular dystrophy. We have previously shown that protein-synthetic rates (ks) are increased in mdx mouse muscles [MacLennan & Edwards (1990) Biochem. J. 268, 795-797]. 2. The tumour-promoting stereoisomer of phorbol 12,13-didecanoate (4 beta-PDD) acutely increased the ks of muscles from mdx and wild-type (C57BL/10) mice incubated in vitro in the absence of insulin. The effects of 4 beta-PDD are presumably mediated by activation of protein kinase C (PKC). 3. The muscle glycogen concentrations of mdx mice were higher than those of C57BL/10 mice. Studies performed in vivo and in vitro suggested that the effect might be at least partially due to increased rate of glycogen synthesis in mdx muscle. 4. 4 beta-PDD increased the glycogen-synthetic rates rates of C57BL/10, but not mdx, muscles incubated in vitro in the absence of insulin. 5. In muscles from both species incubated in the absence of insulin, treatment with 4 beta-PDD also induced increased rates of glucose uptake and lactate production. Kinetic studies of C57BL/10 and mdx muscles suggested that 4 beta-PDD raised the Vmax. of glucose uptake, but did not alter the Km for the process. 6. The possible role of PKC in controlling the protein and carbohydrate metabolism of normal and mdx mouse muscles is discussed.

scholarly journals Impaired lipogenesis in mammary glands of lactating rats fed on a cafeteria diet. Reversal of inhibition of glucose metabolism in vitro by insulin

1980 ◽  
Vol 186 (3) ◽  
pp. 1005-1008 ◽  
Author(s):  
L Agius ◽  
B J Rolls ◽  
E A Rowe ◽  
D H Williamson
Keyword(s):  
Mammary Gland ◽  
Glucose Metabolism ◽  
Glucose Uptake ◽  
Mammary Glands ◽  
High Energy ◽  
Cafeteria Diet ◽  
Chow Diet

In lactating rats fed on a cafeteria diet (chow plus palatable high-energy foods) the decreased glucose uptake and lipogenesis in vitro in acini correlated with the depressed mammary-gland lipogenesis in vivo. Insulin in vitro restored the rate of glucose uptake and its conversion to lipid to values approaching those for acini from rats fed on the chow diet alone.

Formation and Structure of Casein Micelles in Lactating Mammary Tissue

1970 ◽  
Vol 28 ◽  
pp. 150-151
Author(s):  
Robert J. Carroll ◽  
Marvin P. Thompson ◽  
Harold M. Farrell
Keyword(s):  
Size Distribution ◽  
G Protein ◽  
Milk Proteins ◽  
Mammary Tissue ◽  
Colloidal System ◽  
Casein Micelles ◽  
The Stability

Milk is an unusually stable colloidal system; the stability of this system is due primarily to the formation of micelles by the major milk proteins, the caseins. Numerous models for the structure of casein micelles have been proposed; these models have been formulated on the basis of in vitro studies. Synthetic casein micelles (i.e., those formed by mixing the purified αsl- and k-caseins with Ca2+ in appropriate ratios) are dissimilar to those from freshly-drawn milks in (i) size distribution, (ii) ratio of Ca/P, and (iii) solvation (g. water/g. protein). Evidently, in vivo organization of the caseins into the micellar form occurs in-a manner which is not identical to the in vitro mode of formation.

scholarly journals Lactate secreted by PKM2 upregulation promotes Galectin-9-mediated immunosuppression via inhibiting NF-κB pathway in HNSCC

2021 ◽  
Vol 12 (8) ◽  
Author(s):  
Hanyue Chang ◽  
Qiaoshi Xu ◽  
Jiayi Li ◽  
Mingyu Li ◽  
Zhiyuan Zhang ◽  
...  
Keyword(s):  
Critical Role ◽  
Lactate Production ◽  
Metabolic Reprogramming ◽  
Migration And Invasion ◽  
Histone Deacetylase 3 ◽  
Proliferation And Metastasis ◽  
Immunosuppressive Microenvironment ◽  
Transcriptional Complex

AbstractPyruvate kinase M2 as a key rate-limiting enzyme in glycolysis, it plays a critical role in metabolic reprogramming and carcinogenesis. However, whether PKM2 can promote immunosuppressive microenvironment formation remains unknown in head and neck squamous cell carcinoma (HNSCC). PKM2 expression was detected using immunohistochemical staining. The biological functions of PKM2 were investigated in vitro and in vivo. Lactate production and the expression of Galectin-9, a critical immunosuppression molecule, were detected after PKM2 knockdown and overexpression in HNSCC cells. The mechanism of lactate regulating Galectin-9 expression through NF-κB signaling was explored in vitro. Overexpression of PKM2 correlates with poor prognosis in HNSCC patients. Silencing PKM2 markedly inhibits proliferation and metastasis capacity in vivo and in vitro, and vice versa. The glycolysis and glycolytic capacity are significantly decreased after PKM2 silencing. Lactate secretion induced by PKM2 significantly promotes migration and invasion capacity. Furthermore, a positive correlation between PKM2 and Galectin-9 expression is observed in HNSCC tissues. The induction of Galectin-9 expression by PKM2 can be affected by a lactate transporter inhibitor. Mechanically, lactate impeded the suppressive transcriptional complex formation of NF-κB and histone deacetylase 3 (HDAC3), which released the transcription of Galectin-9 mediated by NF-κB signaling. Our findings demonstrate that lactate produced by PKM2 upregulation promotes tumor progression and Galectin-9-mediated immunosuppression via NF-κB signaling inhibition in HNSCC, which bridges metabolism and immunosuppression. The novel PKM2-lactate-Galectin-9 axis might be a potential therapeutic target in HNSCC.

scholarly journals Calcium Supplementation Enhanced Adipogenesis and Improved Glucose Homeostasis Through Activation of Camkii and PI3K/Akt Signaling Pathway in Porcine Bone Marrow Mesenchymal Stem Cells (pBMSCs) and Mice Fed High Fat Diet (HFD)

2018 ◽  
Vol 51 (1) ◽  
pp. 154-172 ◽  
Author(s):  
Fenglin Zhang ◽  
Jingjing Ye ◽  
Yingying Meng ◽  
Wei Ai ◽  
Han Su ◽  
...  
Keyword(s):  
Body Weight ◽  
Glucose Uptake ◽  
Glucose Homeostasis ◽  
High Fat Diet ◽  
Calcium Supplementation ◽  
Akt Signaling Pathway ◽  
Glut4 Expression ◽  
Marrow Mesenchymal Stem Cells

Background/Aims: It has been implicated that calcium supplementation is involved in reducing body weight/fat and improving glucose homeostasis. However, the underlying mechanisms are still not fully understood. Here, we investigated the effects of calcium supplementation on adipogenesis and glucose homeostasis in porcine bone marrow mesenchymal stem cells (pBMSCs) and high fat diet (HFD)-fed mice and explored the involved signaling pathways. Methods: In vitro, pBMSCs were treated with 4 mM extracellular calcium ([Ca2+]o) and/or 1 μM nifedipine, 0.1 μM BAPTA-AM, 1 μM KN-93, 50 nM wortmannin for 10 days. The intracellular calcium ([Ca2+]i) levels were measured using Fluo 3-AM by flow cytometry. The adipogenic differentiation of pBMSCs was determined by Oil Red-O staining and triglyceride assay. The expression of marker genes involved in adipogenesis (peroxisome proliferator activated receptor γ (PPARγ) and CCAAT/enhancer binding protein α (C/EBPα)) and glucose uptake (glucose transporter 4 (GLUT4)), as well as the activation of Ca2+/calmodulin-dependent protein kinase II (CaMKII) and PI3K/Akt-FoxO1/AS160 signaling pathways were determined by Western blotting. Glucose uptake and utilization were examined using 2-NBDG assay and glucose content assay, respectively. In vivo, C57BL/6J male mice were fed a HFD (containing 1.2% calcium) without or with 0.6% (w/w) calcium chloride in drinking water for 13 weeks. The adipogenesis, glucose homeostasis and the involvement of CaMKII and PI3K/Akt signaling pathway were also assessed. Results: In vitro, [Ca2+]o stimulated pBMSCs adipogenesis by increasing [Ca2+]i level and activating CaMKII and PI3K/Akt-FoxO1 pathways. In addition, [Ca2+]o promoted glucose uptake/utilization by enhancing AS160 phosphorylation, GLUT4 expression and translocation. However, the stimulating effects of [Ca2+]o on pBMSCs adipogenesis and glucose uptake/utilization were abolished by L-VGCC blocker Nifedipine, [Ca2+]i chelator BAPTA-AM, CaMKII inhibitor KN-93, or PI3K inhibitor Wortmannin. In vivo, calcium supplementation decreased body weight and fat content, increased adipocyte number, and improved glucose homeostasis, with elevated PPARγ and GLUT4 expression and PI3K/Akt activation in iWAT. Conclusion: calcium supplementation enhanced adipogenesis and glucose uptake in pBMSCs, which was coincident with the increased adipocyte number and improved glucose homeostasis in HFD-fed mice, and was associated with activation of CaMKII and PI3K/Akt-FoxO1/AS160 pathways. These data provided a broader understanding of the mechanisms underlying calcium-induced body weight/fat loss and glycemic control.

scholarly journals α-Hederin Inhibits the Growth of Lung Cancer A549 Cells in vitro and in vivo by Increasing SIRT6 Dependent Glycolysis

2020 ◽  
Author(s):  
cong fang ◽  
Yahui Liu ◽  
Lanying Chen ◽  
Yingying Luo ◽  
Yaru Cui ◽  
...  
Keyword(s):  
Lung Cancer ◽  
Mouse Model ◽  
Protein Expression ◽  
Glucose Uptake ◽  
A549 Cells ◽  
Lactate Production ◽  
Tumor Xenograft ◽  
Xenograft Mouse Model ◽  
Atp Generation

Abstract Background: α-hederin an effective component of Pulsatilla chinensis (Bunge) Regel, Studies showed that α-hederin exert many pharmacological activities, However, the effect of α-hederin on metabolism is still unclear. This study aimed to illuminate the role of α-hederin in glucose metabolism in lung cancer cells and investigate the molecular mechanism of α-hederin. Methods: CCK8 and colony formation assays were employed to assess the anti-proliferative effects induced by α-hederin. Glucose uptake, ATP generation, and reduced lactate production were measured using kits, and an A549 tumor xenograft mouse model of lung cancer was used to assess the in vivo antitumor effect of α-hederin (5, 10 mg/kg). Glycolytic-related key enzymes hexokinase 2 (HK2), glucose transporters 1 (GLUT1), pyruvate kinase M2 (PKM2), lactate dehydrogenase A (LDHA), monocarboxylate transporter (MCT4), c-Myc, Hypoxia inducible factor-1α (HIF-1α) and Sirtuin 6 (SIRT6) protein expression were detected by western blotting and immunohistochemical staining and SIRT6 inhibitors was verified in A549 cells. Results: Our results showed that cell proliferation was significantly inhibited by α-hederin in a dose-dependent manner and that α-hederin inhibited glucose uptake and ATP generation and reduced lactate production. Furthermore, α-hederin remarkably inhibited HK2, GLUT1, PKM2, LDHA, MCT4, c-Myc, HIF-1α and activated SIRT6 protein expression. Using inhibitors, we proved that α-hederin inhibits glycolysis by activating SIRT6. Moreover, a tumor xenograft mouse model of lung cancer further confirmed that α-hederin inhibits lung cancer growth via inhibiting glycolysis in vivo. Conclusions: α-hederin inhibits the growth of non-small cell lung cancer A549 cells by inhibiting glycolysis. The mechanism of glycolysis inhibition includes α-hederin activating the expression of the glycolytic related protein SIRT6.

scholarly journals Human TNF-α Affects the Egg-laying Dynamics and Glucose Metabolism of Schistosoma Mansoni Adult Worms in Vitro

2021 ◽  
Author(s):  
Ednilson Hilário Lopes-Junior ◽  
Gilbert de Oliveira Silveira ◽  
Camila Banca Guedes ◽  
Gratchela Dutra Rodrigues ◽  
Viviane Sousa Ribeiro ◽  
...  
Keyword(s):  
Schistosoma Mansoni ◽  
Mrna Expression ◽  
Glucose Uptake ◽  
Lactate Production ◽  
Egg Laying ◽  
Dependent Manner ◽  
Tnf Α ◽  
Atp Metabolism ◽  
Fine Regulation

Abstract Several studies described the effect of human TNF-α on Schistosoma mansoni. It affects the worm’s development, metabolism, egg-laying, changes in the parasite´s gene expression and protein phosphorylation. Data available concerning the influence of hTNF-α on egg-laying are controversial and understanding the mechanism of egg-laying regulation is essential in combating schistosomiasis. We characterized the effects of in vitro treatment of S. mansoni adult worms with different doses of hTNF-α (5, 20 and 40ng/mL) for five days. We explored the effects on the egg-laying rate, glucose, ATP metabolism, mRNA expression levels of lactate dehydrogenase, of glucose transporters and of SmTNFR, the parasite gene for hTNF-α receptor. hTNF-α influenced egg-laying in a time and dose dependent manner: with 40ng/mL, egg-laying increased on day 2 and decreased on days 3 and 4; 20 ng/mL dose, egg-laying decreased on day 3, while at 5ng/mL dose, egg-laying decreased on day 4. The total number of eggs produced was not affected, but the egg-laying dynamic was altered; the median egg-laying time decreased significantly due to treatment. At 5 and 20ng/mL hTNF-alpha, lactate production diminished on days 3 up to 5, while glucose uptake increased on day 5. At 40ng/mL, glucose uptake diminished on days 1 up to 3, while ATP accumulation was detected on day 5. No significant changes in the mRNA expression were detected in all treatments. Crosstalk involving the hTNF-alpha and the parasite signaling play a role in the fine regulation of the worm´s metabolism and physiology and points to new strategies for disease control.

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