scholarly journals High Glucose-enhanced Acetylcholine Stimulated CGMP Masks Impaired Vascular Reactivity in Tail Arteries from Short-Term Hyperglycemic Rats

2000 ◽  
Vol 1 (1) ◽  
pp. 69-79 ◽  
Author(s):  
Marwan Hamaty ◽  
Cristina B. Guzmán ◽  
Mary F. Walsh ◽  
Ann M. Bode ◽  
Joseph Levy ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
High Glucose ◽  
Vascular Function ◽  
No Production ◽  
Short Term ◽  
Contractile Responses ◽  
Vascular Responses ◽  
Short Term Exposure ◽  
Endothelium Dependent Relaxation

Impaired vascular endothelium-dependent relaxation and augmented contractile responses have been reported in several models of long-term hyperglycemia. However, the effects of short-term ambient hyperglycemia are poorly understood. Since oxidative stress has been implicated as a contributor to impaired vascular function, we investigated the following:Aims: (1) the effects of high glucose exposurein vitro(7 – 10 days) on vascular relaxation to acetylcholine (Ach) and contractility to norepinephrine (NE) and KCl; (2) if NO-dependent cGMP generation is affected under these conditions; and (3) aortic redox status.Methods: Non-diabetic rat tail artery rings were incubated in normal (5mM) (control NG) or high (20mM) glucose buffer (control HG). Vascular responses to Ach, NE and KCl were compared to those of streptozotocin (SZ) diabetic animals in the same buffers (diabetic NG, diabetic HG). Ach stimulated cGMP levels were quantitated as an indirect assessment of endothelial nitric oxide (NO) production and oxidative stress evaluated by measuring vascular glutathione and oxidized glutathione.Results: Rings from diabetic rats in NG showed impaired relaxation to Ach (P= 0.002) but relaxed normally, when maintained in HG. Similarly, contractile responses to NE were attenuated in diabetic rings in NG but similar to controls in HG. HG markedly augmented maximal contraction to KCl compared to control and diabetic vessels in NG (P< 0.0001). Diabetic vessels in a hyperosmolar, but normoglycemic, milieu respond like those in HG.in vitro, HG for 2 hours changed neither relaxation nor contractile responses to NE and KCl in control rings. Basal cGMP levels were lower in aortae from diabetic animals pre-incubated in NG than in HG/LG or in control rings in NG (P< 0.05). cGMP responses to Ach were exaggerated in diabetic vessels in HG (P= 0.035vs. control NG,P= 0.043vs. diabetic NG) but not different between control and diabetic rings in NG. Vessels from diabetic animals had lower levels of GISH (P< 0.0001) and higher levels of GSSG (P< 0.0001) indicating oxidative stress.Conclusions: Our data indicate that endothelium dependent relaxation is altered early in the diabetic state and that increased NO responses may compensate for augmented oxidative stress but the lack of effect of short-term exposure of normal vessels to HG suggests that short-term hyperglycemiaper sedoes not cause abnormal vascular responses.

229 SHORT-TERM EXPOSURE OF MATURE OOCYTES TO A NITRIC OXIDE DONOR FOR INDUCING OXIDATIVE STRESS RESISTANCE ON IN VITRO-PRODUCED BOVINE EMBRYOS

2015 ◽  
Vol 27 (1) ◽  
pp. 204
Author(s):  
C. Cheuquemán ◽  
P. Loren ◽  
M. Arias ◽  
J. Risopatrón ◽  
R. Felmer ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Gene Expression ◽  
Embryo Quality ◽  
Nitric Oxide Donor ◽  
Control Group ◽  
Relative Gene Expression ◽  
Short Term ◽  
Short Term Exposure ◽  
Relative Gene

Recent studies have shown that short-term exposure of oocytes to stressors such as hydrostatic pressure, osmotic stress, and oxidative stress might induce stress tolerance in embryos. In this research we studied the effect of short-term exposure of bovine in vitro-matured cumulus-oocyte complexes (COC) with a nitric oxide donor (SNP) on IVF, embryo development, embryo quality, and relative gene expression related to cell redox state regulation. The COC were selected and matured in TCM 199 supplemented with 10% inactivated FBS, 6 mg mL–1 of LH, 6 mg mL–1 of FSH, 1 mg mL–1 of oestradiol, and 0.2 mmol of pyruvate and then incubated for 22 to 24 h at 38.5°C in 5% CO2 in a humidified atmosphere (n = 12). Before IVF, mature COC were incubated during 1 h with different concentration of sodium nitroprusside, SNP (control without SNP, 10–6 M, 10–5 M, and 10–4 M SNP) in maturation media at 38.5°C and 5% CO2 in a humidified atmosphere. For IVF procedure, oocytes of each treatment and sperm of one bull were co-incubated for 18 to 20 h at 38.5°C and 5% CO2. Presumptive zygotes were separately cultured until Day 7 under mineral oil at 38.5°C and 5% CO2, 5%O2, and 90% N2 in a humidified atmosphere. Embryo quality was analysed by staining with CDX2 antibody for trophectoderm cells and compared with total embryo cells stained with Hoechst 33342. Relative gene expression for each treatment were evaluated after RNA extraction and cDNA synthesis in Stratagene MX 3000P real-time equipment with Agilent qPCR software MX pro 4.1 version. Differences between experimental groups (n = 12) were measured using a one-way ANOVA test in the STATGRAPHICS plus 5.1 version software. P < 0.05 was considered statistically significant. Cleavage percentage at 72 h post-insemination was significantly different between the control and 10–4 M SNP group (82 ± 8.4% v. 77 ± 7.1%, respectively) and between 10–5 M and 10–4 M SNP group (84.9 ± 4.1% v. 77 ± 7.1%, respectively). Blastocyst percentage at 7 days of culture was significantly different between control and 10–4 M SNP group (34.1 ± 7.8% v. 26.2 ± 4.9%, respectively). Embryo development between control group and treatments was similar within early, expanded, and hatched blastocyst percentage. Embryo quality of expanded blastocyst was similar between control group and treatments (ICM: TE). No significant differences in gene expression after SNP exposure was observed (iNOS, eNOS, nNOS, PRDX5, HSP70, HSP90, HIF1A, BCL2A). Oocytes incubated with a high concentration of SNP showed lower cleavage and blastocyst rates, showing that this treatment was deleterious for in vitro embryo production in bovine. However, there were no significant differences on embryo quality assessed by ICM : TE ratio and/or in gene expression pattern of 7-day cultured expanded blastocysts.

The Effect of Dimethyl Sulfoxide on In Vitro Platelet Function

1976 ◽  
Vol 36 (01) ◽  
pp. 221-229 ◽  
Author(s):  
Charles A. Schiffer ◽  
Caroline L. Whitaker ◽  
Morton Schmukler ◽  
Joseph Aisner ◽  
Steven L. Hilbert
Keyword(s):  
Platelet Count ◽  
Platelet Aggregation ◽  
Dimethyl Sulfoxide ◽  
Platelet Function ◽  
Platelet Volume ◽  
Short Term ◽  
Platelet Factor ◽  
Short Term Exposure ◽  
Structural Abnormalities

SummaryAlthough dimethyl sulfoxide (DMSO) has been used extensively as a cryopreservative for platelets there are few studies dealing with the effect of DMSO on platelet function. Using techniques similar to those employed in platelet cryopreservation platelets were incubated with final concentrations of 2-10% DMSO at 25° C. After exposure to 5 and 10% DMSO platelets remained discoid and electron micrographs revealed no structural abnormalities. There was no significant change in platelet count. In terms of injury to platelet membranes, there was no increased availability of platelet factor-3 or leakage of nucleotides, 5 hydroxytryptamine (5HT) or glycosidases with final DMSO concentrations of 2.5, 5 and 10% DMSO. Thrombin stimulated nucleotide and 5HT release was reduced by 10% DMSO. Impairment of thrombin induced glycosidase release was noted at lower DMSO concentrations and was dose related. Similarly, aggregation to ADP was progressively impaired at DMSO concentrations from 1-5% and was dose related. After the platelets exposed to DMSO were washed, however, aggregation and release returned to control values. Platelet aggregation by epinephrine was also inhibited by DMSO and this could not be corrected by washing the platelets. DMSO-plasma solutions are hypertonic but only minimal increases in platelet volume (at 10% DMSO) could be detected. Shrinkage of platelets was seen with hypertonic solutions of sodium chloride or sucrose suggesting that the rapid transmembrane passage of DMSO prevented significant shifts of water. These studies demonstrate that there are minimal irreversible alterations in in vitro platelet function after short-term exposure to DMSO.

Long noncoding RNA OIP5-AS1 overexpression promotes viability and inhibits high glucose-induced oxidative stress of cardiomyocytes by targeting microRNA-34a/SIRT1 axis in diabetic cardiomyopathy

2020 ◽  
Vol 21 ◽  
Author(s):  
Haiyun Sun ◽  
Chong Wang ◽  
Ying Zhou ◽  
Xingbo Cheng
Keyword(s):  
Oxidative Stress ◽  
Protein Expression ◽  
Diabetic Cardiomyopathy ◽  
High Glucose ◽  
Long Noncoding Rna ◽  
Noncoding Rna ◽  
Luciferase Reporter ◽  
H9c2 Cells ◽  
Promoting Effect

Objective: Diabetic cardiomyopathy (DCM) is an important complication of diabetes. This study was attempted to discover the effects of long noncoding RNA OIP5-AS1 (OIP5-AS1) on the viability and oxidative stress of cardiomyocyte in DCM. Methods: The expression of OIP5-AS1 and microRNA-34a (miR-34a) in DCM was detected by qRT-PCR. In vitro, DCM was simulated by high glucose (HG, 30 mM) treatment in H9c2 cells. The viability of HG (30 mM)-treated H9c2 cells was examined by MTT assay. The reactive oxygen species (ROS), superoxide dismutase (SOD) and malondialdehyde (MDA) levels were used to evaluate the oxidative stress of HG (30 mM)-treated H9c2 cells. Dual-luciferase reporter assay was used to confirm the interactions among OIP5-AS1, miR-34a and SIRT1. Western blot was applied to analyze the protein expression of SIRT1. Results: The expression of OIP5-AS1 was down-regulated in DCM, but miR-34a was up-regulated. The functional experiment stated that OIP5-AS1 overexpression increased the viability and SOD level, while decreased the ROS and MDA levels in HG (30 mM)-treated H9c2 cells. The mechanical experiment confirmed that OIP5-AS1 and SIRT1 were both targeted by miR-34a with the complementary binding sites at 3′UTR. MiR-34a overexpression inhibited the protein expression of SIRT1. In the feedback experiments, miR-34a overexpression or SIRT1 inhibition weakened the promoting effect on viability, and mitigated the reduction effect on oxidative stress caused by OIP5-AS1 overexpression in HG (30 mM)-treated H9c2 cells. Conclusions: OIP5-AS1 overexpression enhanced viability and attenuated oxidative stress of cardiomyocyte via regulating miR-34a/SIRT1 axis in DCM, providing a new therapeutic target for DCM.

Soft agar cloning evaluation of effects of amifostine on clonogenic growth of freshly explanted human tumors in short term exposure in vitro

1997 ◽  
Vol 33 ◽  
pp. S178
Author(s):  
P. Pohl ◽  
H. Depenbrock ◽  
R. Peter ◽  
P. Schmid ◽  
J. Rastetter ◽  
...  
Keyword(s):  
Soft Agar ◽  
Human Tumors ◽  
Short Term ◽  
Clonogenic Growth ◽  
Short Term Exposure ◽  
Soft Agar Cloning

Proliferation and agglutinability of primary and transformed human epithelial cells in culture

1976 ◽  
Vol 21 (3) ◽  
pp. 553-561
Author(s):  
M.A. Ricard ◽  
R.J. Hay
Keyword(s):  
Culture Medium ◽  
Monolayer Culture ◽  
Primary Cultures ◽  
Short Term ◽  
Chloromethyl Ketone ◽  
Normal Populations ◽  
Short Term Exposure ◽  
Cell Strains ◽  
Human Placentae

Primary epithelial populations (HAM) were obtained by dissociation of the amniotic membrane stripped from human placentae. Agglutinability of cells from such normal populations and of cells from the transformed epithelial line WISH was then compared using concavanalin A as mediator. Extensive similar studies have previously been reported with cell strains isolated from other species. Freshly dissociated HAM cells from primary cultures agglutinated much less readily than did cells from WISH populations. Furthermore, the former exhibited a drastic decline in agglutinability as a function of time in suspension culture after trypsinization. Short-term exposure (60 h) of HAM cells in monolayer culture to 5-bromodeoxyuridine (BrdU) elicited heightened agglutinability detectable through 22 days in vitro. Addition of the protease inhibitors n-tosyl-L-lysyl-chloromethyl ketone (TLCK) or p-tosyl-L-arginine-methyl ester (TAME) to the culture medium inhibited proliferation of the WISH line by 40–50% while effecting only a 10–15% inhibition of HAM cells. These results also confirm data with other cell species indicating that high proteolytic activity at the surface of transformed cells may be related to the rapid proliferation rate.

scholarly journals Hexarelin exerts neuroprotective and antioxidant effects against hydrogen peroxide-induced toxicity through the modulation of MAPK and PI3K/Akt patways in Neuro-2A cells

2020 ◽  
Author(s):  
Ramona Meanti ◽  
Laura Rizzi ◽  
Elena Bresciani ◽  
Laura Molteni ◽  
Vittorio Locatelli ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Hydrogen Peroxide ◽  
Apoptotic Cell ◽  
Neuroblastoma Cell ◽  
Neuroblastoma Cell Line ◽  
Inhibitory Influence ◽  
No Production ◽  
Mrna Levels

AbstractHexarelin, a synthetic hexapeptide, protects cardiac and skeletal muscles by inhibiting apoptosis, both in vitro and in vivo. Moreover, evidence suggests that hexarelin could have important neuroprotective bioactivity.Oxidative stress and the generation of free radicals has been implicated in the etiologies of several neurodegenerative diseases, including amyotrophic lateral sclerosis, Parkinson’s disease, Alzheimer’s disease, Huntington’s disease and multiple sclerosis. In addition to direct oxidative stress, exogenous hydrogen peroxide (H2O2) can penetrate biological membranes and enhance the formation of other reactive oxygen species.The aim of this study was to examine the inhibitory influence of hexarelin on H2O2-induced apoptosis in Neuro-2A cells, a mouse neuroblastoma cell line. Our results indicate that H2O2 reduced the viability of Neuro-2A cells in a dose-related fashion. Furthermore, H2O2 induced significant changes in the morphology of Neuro-2A cells, reflected in the formation of apoptotic cell bodies, and an increase of nitric oxide (NO) production. Hexarelin effectively antagonized H2O2 oxidative damage to Neuro-2A cells as indicated by improved cell viability, normal morphology and reduced nitrite (NO2−) release. Hexarelin treatment of Neuro-2A cells also reduced mRNA levels of caspases−3 and −7 and those of the pro-apoptotic molecule Bax; by contrast, hexarelin treatment increased anti-apoptotic Bcl-2 mRNA levels. Hexarelin also reduced MAPKs phosphorylation induced by H2O2 and concurrently increased p-Akt protein expression.In conclusion, our results identify several neuroprotective and anti-apoptotic effects of hexarelin. These properties suggest that further investigation of hexarelin as a neuroprotective agent in an investigational and therapeutic context are merited.

scholarly journals Protection of the vascular endothelium in experimental situations

2011 ◽  
Vol 4 (1) ◽  
pp. 20-26 ◽  
Author(s):  
Ružena Sotníková ◽  
Jana Nedelčevová ◽  
Jana Navarová ◽  
Viera Nosáľová ◽  
Katarína Drábiková ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Vascular Endothelium ◽  
Vascular Dysfunction ◽  
Antioxidant Properties ◽  
Pharmacological Intervention ◽  
Ros Production ◽  
Nitric Oxide Radical ◽  
Endothelium Dependent Relaxation

Protection of the vascular endothelium in experimental situationsOne of the factors proposed as mediators of vascular dysfunction observed in diabetes is the increased generation of reactive oxygen species (ROS). This provides support for the use of antioxidants as early and appropriate pharmacological intervention in the development of late diabetic complications. In streptozotocin (STZ)-induced diabetes in rats we observed endothelial dysfuction manifested by reduced endothelium-dependent response to acetylcholine of the superior mesenteric artery (SMA) and aorta, as well as by increased endothelaemia. Changes in endothelium-dependent relaxation of SMA were induced by injury of the nitric oxide radical (·NO)-signalling pathway since the endothelium-derived hyperpolarising factor (EDHF)-component of relaxation was not impaired by diabetes. The endothelial dysfunction was accompanied by decreased ·NO bioavailabity as a consequence of reduced activity of eNOS rather than its reduced expression. The results obtained using the chemiluminiscence method (CL) argue for increased oxidative stress and increased ROS production. The enzyme NAD(P)H-oxidase problably participates in ROS production in the later phases of diabetes. Oxidative stress was also connected with decreased levels of reduced glutathione (GSH) in the early phase of diabetes. After 10 weeks of diabetes, adaptational mechanisms probably took place because GSH levels were not changed compared to controls. Antioxidant properties of SMe1EC2 foundin vitrowere partly confirmedin vivo.Administration of SMe1EC2 protected endothelial function. It significantly decreased endothelaemia of diabetic rats and improved endothelium-dependent relaxation of arteries, slightly decreased ROS-production and increased bioavailability of ·NO in the aorta. Further studies with higher doses of SMe1EC2 may clarify the mechanism of its endothelium-protective effectin vivo.

Abstract 6253: Increased Expression of Thioredoxin Interacting Protein Promotes Oxidative Stress and Contributes to the Pathogenesis Of Diabetic Cardiomyopathy

Circulation ◽  
2008 ◽  
Vol 118 (suppl_18) ◽  
Author(s):  
Kim A Connelly ◽  
Darren J Kelly ◽  
Michael Zhang ◽  
Kerri Thai ◽  
Andrew Advani ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Mrna Expression ◽  
High Glucose ◽  
Diastolic Heart Failure ◽  
Transgenic Rat ◽  
Interacting Protein ◽  
Thioredoxin Interacting Protein ◽  
Neonatal Cardiomyocytes

Background: Alterations in the thioredoxin (TRX) antioxidant system have been implicated in the pathogenesis of cardiac injury, particularly in the diabetic setting. While constitutively present, TRX activity is reduced by the presence of its endogenous inhibitor, thioredoxin interacting protein (TxnIP). We hypothesized that by increasing TxnIP, diabetes may reduce TRX activity and contribute to oxidative stress. Methods: Cell culture studies were performed using the H9C2 rat cardiomyoblast cell line and neonatal cardiomyocytes isolated from 1 day old Sprague Dawley rat neonates. In-vivo studies were performed using a hemodynamically-validated rodent model of diabetic diastolic heart failure, the diabetic (mRen-2)27 transgenic rat (Ren-2). Urinary 8-hydroxy-2′-deoxyguanosine (8-OHdG) was used as a measure of oxidative stress. Results: In- vitro, high glucose (25mmol/l) resulted in increased TxnIP mRNA expression in both neonatal cardiomyocytes as well as H92C cells (2.21 ± 0.6 v 1.00 ± 0.19, p<0.05 compared to normoglycaemic conditions) with a 45% reduction in TRX activity (0.11 ± 0.01 v 0.061± 0.003, p<0.01). In-vivo, diabetes led to a 250% rise in TxnIP mRNA expression compared to control (2.54 ± 0.5 v 1.00 ± 0.11, p<0.001) that was accompanied by a three fold rise in urinary 8-OHdG (680 ± 280 v 1395 ± 391 ng/ml, p<0.001). Conclusion: In both the in vitro and in vivo settings, high glucose leads to TxnIP over-expression associated with reduced TRX activity thereby increasing oxidative stress and implicating this system in the pathogenesis of the cardiac dysfunction that characterizes the diabetic state. Pharmacological manipulation of the TRX-TxnIP system may represent a novel target to reduce diabetic complications.

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