scholarly journals The effects of amylin on carbohydrate metabolism in skeletal muscle in vitro and in vivo

1990 ◽  
Vol 269 (1) ◽  
pp. 19-23 ◽  
Author(s):  
B Leighton ◽  
E Foot
Keyword(s):  
Glucose Utilization ◽  
Glycogen Synthesis ◽  
Intraperitoneal Administration ◽  
Muscle Preparation ◽  
Glucose Incorporation ◽  
Rat Soleus Muscle ◽  
Lactate Formation ◽  
Human Amylin

1. The effects of synthetic human amylin on basal and insulin-stimulated (100 and 1000 microunits/ml) rates of lactate formation, glucose oxidation and glycogen synthesis were measured in the isolated rat soleus muscle preparation incubated in the presence of various concentrations of glucose (5, 11 and 22 mM). 2. The rate of glucose utilization was increased by about 2-fold by increasing the glucose concentration from 5 to 22 mM. 3. Synthetic human amylin (10 nM) significantly inhibited (by 46-56%) glycogen synthesis, irrespective of the concentration of insulin or glucose present in the incubation medium. 4. Amylin (10 nM) did not affect insulin-stimulated rates of 2-deoxy[3H]glucose transport and phosphorylation. 5. Intraperitoneal administration of insulin (100 micrograms/kg) to rats in vivo stimulated the rate of [U-14C]glucose incorporation into glycogen in the diaphragm by about 80-fold. This rate was decreased (by 28%) by co-administration of amylin (66 micrograms/kg).

Insulin sensitivity of rates of glycolysis and glycogen synthesis in soleus, stripped soleus, epitrochlearis, and hemi-diaphragm muscles isolated from sedentary rats

1983 ◽  
Vol 3 (7) ◽  
pp. 675-679 ◽  
Author(s):  
R. A. J. Challiss ◽  
J. Espinal ◽  
E. A. Newsholme
Keyword(s):  
Fatty Acid ◽  
Glucose Utilization ◽  
Glycogen Synthesis ◽  
Maximal Inhibition ◽  
Maximal Stimulation ◽  
Glucose Fatty Acid Cycle ◽  
Isolated Adipocytes ◽  
Stimulation Of

The effect of insulin concentrations on the rates of glycolysis and glycogen synthesis in four different in vitro rat muscle preparations (intact soleus, stripped soleus, epitrochlearis, and hemi-diaphragm) were investigated: the concentrations of insulin that produced half-maximal stimulation of the rates of these two processes in the four muscle preparations were similar – about 100 μunits/ml. This is at least 10-fold greater than the concentration that produced half-maximal inhibition of lipolysis in isolated adipocytes. Since 100 μunits/ml insulin is outside the normal physiological range in the rat, it is suggested that, in vivo, insulin influences glucose utilization in muscle mainly indirectly, via changes in the plasma fatty acid levels and the ‘glucose/fatty acid cycle’. Consequently the view that insulin stimulates glucose utilization in muscle mainly by a direct effect on membrane transport must be treated with caution.

scholarly journals Furosemide decreases the sensitivity of glucose transport to insulin in skeletal muscle in vitro

1998 ◽  
Vol 139 (1) ◽  
pp. 118-122 ◽  
Author(s):  
G Dimitriadis ◽  
B Leighton ◽  
M Parry-Billings ◽  
C Tountas ◽  
S Raptis ◽  
...  
Keyword(s):  
Skeletal Muscle ◽  
Glucose Transport ◽  
Soleus Muscle ◽  
Transport Process ◽  
Glucose Utilization ◽  
Glucose Disposal ◽  
Rat Soleus Muscle ◽  
Lactate Formation

The effects of the diuretic furosemide on the sensitivity of glucose disposal to insulin were investigated in rat soleus muscle in vitro. At basal levels of insulin, the rates of 3-O-methylglucose transport, 2-deoxyglucose phosphorylation and lactate formation were not affected significantly by furosemide (0.5 mmol/l). However, furosemide significantly decreased these rates at physiological and maximal levels of insulin. The contents of 2-deoxyglucose and glucose 6-phosphate in the presence of furosemide were not significantly different from those in control muscles at all levels of insulin studied. It is concluded that furosemide decreases the sensitivity of glucose utilization to insulin in skeletal muscle by directly inhibiting the glucose transport process.

In vitro autoregulation of glucose utilization in rat soleus muscle

Diabetes ◽  
1987 ◽  
Vol 36 (9) ◽  
pp. 1041-1046 ◽  
Author(s):  
S. Sasson ◽  
D. Edelson ◽  
E. Cerasi
Keyword(s):  
Soleus Muscle ◽  
Glucose Utilization ◽  
Rat Soleus Muscle

scholarly journals KUS121 attenuates the progression of monosodium iodoacetate-induced osteoarthritis in rats

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Sachiko Iwai ◽  
Hanako O. Ikeda ◽  
Hisashi Mera ◽  
Kohei Nishitani ◽  
Motoo Saito ◽  
...  
Keyword(s):  
Cell Death ◽  
Er Stress ◽  
Apoptotic Cell ◽  
Intraperitoneal Administration ◽  
Atp Depletion ◽  
Knee Joints ◽  
Cellular Protection ◽  
Monosodium Iodoacetate

AbstractCurrently there is no effective treatment available for osteoarthritis (OA). We have recently developed Kyoto University Substances (KUSs), ATPase inhibitors specific for valosin-containing protein (VCP), as a novel class of medicine for cellular protection. KUSs suppressed intracellular ATP depletion, endoplasmic reticulum (ER) stress, and cell death. In this study, we investigated the effects of KUS121 on chondrocyte cell death. In cultured chondrocytes differentiated from ATDC5 cells, KUS121 suppressed the decline in ATP levels and apoptotic cell death under stress conditions induced by TNFα. KUS121 ameliorated TNFα-induced reduction of gene expression in chondrocytes, such as Sox9 and Col2α. KUS121 also suppressed ER stress and cell death in chondrocytes under tunicamycin load. Furthermore, intraperitoneal administration of KUS121 in vivo suppressed chondrocyte loss and proteoglycan reduction in knee joints of a monosodium iodoacetate-induced OA rat model. Moreover, intra-articular administration of KUS121 more prominently reduced the apoptosis of the affected chondrocytes. These results demonstrate that KUS121 protects chondrocytes from stress-induced cell death in vitro and in vivo, and indicate that KUS121 is a promising novel therapeutic agent to prevent the progression of OA.

scholarly journals EXTH-51. ANTI-INVASIVE EFFICACY AND SURVIVAL BENEFIT OF THE YAP-TEAD INHIBITOR VERTEPORFIN IN PRECLINICAL GLIOBLASTOMA MODELS

2020 ◽  
Vol 22 (Supplement_2) ◽  
pp. ii98-ii98
Author(s):  
Anne Marie Barrette ◽  
Alexandros Bouras ◽  
German Nudelman ◽  
Zarmeen Mussa ◽  
Elena Zaslavsky ◽  
...  
Keyword(s):  
Survival Benefit ◽  
De Novo ◽  
Epithelial Mesenchymal Transition ◽  
Intraperitoneal Administration ◽  
Standard Of Care ◽  
Tumor Burden ◽  
Mesenchymal Transition ◽  
Protein Levels

Abstract Glioblastoma (GBM) remains an incurable disease, in large part due to its malignant infiltrative spread, and current clinical therapy fails to target the invasive nature of tumor cells in disease progression and recurrence. Here, we use the YAP-TEAD inhibitor Verteporfin to target a convergence point for regulating tumor invasion/metastasis and establish the robust anti-invasive therapeutic efficacy of this FDA-approved drug and its survival benefit across several preclinical glioma models. Using patient-derived GBM cells and orthotopic xenograft models (PDX), we show that Verteporfin treatment disrupts YAP/TAZ-TEAD activity and processes related to cell adhesion, migration and epithelial-mesenchymal transition. In-vitro, Verteporfin impairs tumor migration, invasion and motility dynamics. In-vivo, intraperitoneal administration of Verteporfin in mice with orthotopic PDX tumors shows consistent drug accumulation within the brain and decreased infiltrative tumor burden, across three independent experiments. Interestingly, PDX tumors with impaired invasion after Verteporfin treatment downregulate CDH2 and ITGB1 adhesion protein levels within the tumor microenvironment. Finally, Verteporfin treatment confers survival benefit in two independent PDX models: as monotherapy in de-novo GBM and in combination with standard-of-care chemoradiation in recurrent GBM. These findings indicate potential therapeutic value of this FDA-approved drug if repurposed for GBM patients.

Glucose utilization by sheep embryos derived in vivo and in vitro

1991 ◽  
Vol 3 (5) ◽  
pp. 571 ◽  
Author(s):  
JG Thompson ◽  
AC Simpson ◽  
PA Pugh ◽  
RW Wright ◽  
HR Tervit
Keyword(s):  
Glucose Oxidation ◽  
Glucose Utilization ◽  
Tricarboxylic Acid Cycle ◽  
Tricarboxylic Acid ◽  
Cell Stage ◽  
Glycolytic Activity ◽  
Total Utilization ◽  
Oxidation Of Glucose

Embryos were collected from superovulated donors at various intervals from onset of oestrus, ranging from Day 1.5 to Day 6. In addition, blastocysts obtained from the culture of 1-cell embryos collected in vivo or of oocytes matured and fertilized in vitro were used to assess the effects of in vitro manipulation and culture on glucose utilization. Glycolytic activity was determined by the conversion of [5-3H]glucose to 3H2O, and oxidation of glucose was determined by the conversion of [U-14C]glucose to 14CO2. Glucose utilization increases significantly from the 8-cell stage and during compaction and blastulation. Glucose oxidation was at a relatively low level (5-12% of total utilization) compared with glycolysis. No difference was observed between the glycolytic activity of blastocysts derived from in vivo or in vitro sources. However, glucose oxidation was lower (P less than 0.05) in blastocysts derived from the culture of 1-cell embryos or from oocytes matured and fertilized in vitro. Exogenous tricarboxylic acid cycle substrates (i.e. pyruvate and lactate supplied in the medium) affected the level of glucose oxidation.

scholarly journals The effects of salicylate on the activity of rat liver tyrosine–2-oxoglutarate aminotransferase in vitro and in vivo

1972 ◽  
Vol 126 (2) ◽  
pp. 347-350 ◽  
Author(s):  
A. A.-B. Badawy
Keyword(s):  
Rat Liver ◽  
Pyridoxal Phosphate ◽  
Actinomycin D ◽  
Sodium Salicylate ◽  
Intraperitoneal Administration ◽  
Tyrosine Aminotransferase ◽  
Major Effect ◽  
Endogenous Activity

1. Salicylate, in concentrations of 0.25mm and above, enhances the basal activity of tyrosine–2-oxoglutarate aminotransferase in homogenates of rat liver incubated in the absence of added pyridoxal 5′-phosphate (endogenous activity). The effect is decreased by increasing the concentration of the cofactor. 2. The intraperitoneal administration of sodium salicylate enhances the activity of rat liver tyrosine aminotransferase; the major effect during the first hour being on the enzyme in the absence of added pyridoxal phosphate. Actinomycin D prevents the induction of the enzyme by cortisol and tryptophan. Induction by pyridoxine or salicylate is 50% inhibited by actinomycin D. The effects of the injections of various combinations of cortisol, pyridoxine and salicylate were also studied in the absence or presence of actinomycin D. 3. It is suggested that salicylate induces rat liver tyrosine aminotransferase by displacing its protein-bound cofactor and that a cofactor-type induction of the hepatic enzyme occurs in pyridoxine-treated rats.

scholarly journals p53 upregulated by HIF-1α promotes hypoxia-induced G2/M arrest and renal fibrosis in vitro and in vivo

2018 ◽  
Vol 11 (5) ◽  
pp. 371-382 ◽  
Author(s):  
Limin Liu ◽  
Peng Zhang ◽  
Ming Bai ◽  
Lijie He ◽  
Lei Zhang ◽  
...  
Keyword(s):  
Cell Cycle ◽  
Transcriptional Activation ◽  
Renal Fibrosis ◽  
Intraperitoneal Administration ◽  
Luciferase Reporter ◽  
Loss Of Function ◽  
P53 Expression ◽  
Tubular Cells

Abstract Hypoxia plays an important role in the genesis and progression of renal fibrosis. The underlying mechanisms, however, have not been sufficiently elucidated. We examined the role of p53 in hypoxia-induced renal fibrosis in cell culture (human and rat renal tubular epithelial cells) and a mouse unilateral ureteral obstruction (UUO) model. Cell cycle of tubular cells was determined by flow cytometry, and the expression of profibrogenic factors was determined by RT-PCR, immunohistochemistry, and western blotting. Chromatin immunoprecipitation and luciferase reporter experiments were performed to explore the effect of HIF-1α on p53 expression. We showed that, in hypoxic tubular cells, p53 upregulation suppressed the expression of CDK1 and cyclins B1 and D1, leading to cell cycle (G2/M) arrest (or delay) and higher expression of TGF-β, CTGF, collagens, and fibronectin. p53 suppression by siRNA or by a specific p53 inhibitor (PIF-α) triggered opposite effects preventing the G2/M arrest and profibrotic changes. In vivo experiments in the UUO model revealed similar antifibrotic results following intraperitoneal administration of PIF-α (2.2 mg/kg). Using gain-of-function, loss-of-function, and luciferase assays, we further identified an HRE3 region on the p53 promoter as the HIF-1α-binding site. The HIF-1α–HRE3 binding resulted in a sharp transcriptional activation of p53. Collectively, we show the presence of a hypoxia-activated, p53-responsive profibrogenic pathway in the kidney. During hypoxia, p53 upregulation induced by HIF-1α suppresses cell cycle progression, leading to the accumulation of G2/M cells, and activates profibrotic TGF-β and CTGF-mediated signaling pathways, causing extracellular matrix production and renal fibrosis.

scholarly journals ANTIOXIDANT PROPERTIES OF SINAPIC ACID: IN VITRO AND IN VIVO APPROACH

2017 ◽  
Vol 10 (6) ◽  
pp. 255 ◽  
Author(s):  
Nithya R ◽  
Subramanian S
Keyword(s):  
Antioxidant Properties ◽  
Intraperitoneal Administration ◽  
Radical Scavenging ◽  
Sinapic Acid ◽  
Lipid Peroxides ◽  
Diabetic Rats ◽  
Antioxidant Potential ◽  
Protein Carbonyls

Objective: This study was aimed to evaluate the antioxidant potential of sinapic acid in both in vitro and in vivo. Recently, we have reported that oral administration of sinapic acid (3,5-dimethoxy 4-hydroxycinnamic acid) an active phyto ingredient widely distributed in rye, mustard, berries, and vegetables has been shown to ameliorate hyperglycemia.Methods: Experimental Type 2 diabetes was induced in male Wistar rats by feeding high-fat diet to induce insulin resistance followed by intraperitoneal administration of a single low dose streptozotocin (35 mg/kg body weight [bw]). Sinapic acid was administered orally at a concentration of 25 mg/kg bw/rat/day for 30 days, and its efficacy was compared with metformin. In vitro, antioxidant scavenging properties of sinapic acid were determined using 1,1-diphenyl-2-picrylhydrazyl (DPPH), 2,2’-azino-bis(3-ethylbenzothiazoline-6-sulphonic acid) (ABTS), superoxide, and nitric oxide (NO) assay.Results: Sinapic acid treatment showed a significant decline in the levels of lipid peroxides, hydroperoxides and protein carbonyls in the plasma and vital tissues of diabetic rats. The treatment also improved the antioxidant status in diabetic rats indicating the antioxidant potential of sinapic acid. In addition, the results of DPPH, ABTS, superoxide, and NO radical scavenging assays substantiate the free radical scavenging efficacy of sinapic acid.Conclusion: The results of this study evidenced that sinapic acid possess significant antioxidant properties which in turn may be responsible for its antidiabetic properties.

Cannabinoid effects on adenylate cyclase and phosphodiesterase activities of mouse brain

1977 ◽  
Vol 55 (4) ◽  
pp. 934-942 ◽  
Author(s):  
Thomas W. Dolby ◽  
Lewis J. Kleinsmith
Keyword(s):  
Cyclic Amp ◽  
Adenylate Cyclase ◽  
Mouse Brain ◽  
Biogenic Amine ◽  
Specific Activity ◽  
Intraperitoneal Administration ◽  
The Brain

The experiments presented in this paper examine the mechanisms underlying the ability of cannabinoids to alter the in vivo levels of cyclic adenosine 3′,5′-monophosphate (cyclic AMP) in mouse brain. It was found that changes in cyclic AMP levels are a composite result of direct actions of cannabinoids on adenylate cyclase (EC 4.6.1.1) activity and indirect actions involving the potentiation or inhibition of biogenic amine induced activity of adenylate cyclase. Furthermore, the long-term intraperitoneal administration of 1-(−)-Δ-tetrahydrocannabinol to mice produced a form of phosphodiesterase (EC 3.1.4.17) in the brain whose activity is not stimulated by Ca2+, although its basal specific activity is similar to that of control animals. In vitro, the presence of the cannabinoids caused no significant changes in activity of brain PDE at the concentrations tested. Some correlations are presented which imply that many of the observed behavioral and physiological actions of the cannabinoids in mammalian organisms may be mediated via cyclic AMP mechanisms.

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