scholarly journals Functional alterations of G-proteins in diabetic rat retina: a possible explanation for the early visual abnormalities in diabetes mellitus

Diabetologia ◽  
1992 ◽  
Vol 35 (7) ◽  
pp. 624-631 ◽  
Author(s):  
A. Kowluru ◽  
R. A. Kowluru ◽  
A. Yamazaki
Keyword(s):  
Diabetes Mellitus ◽  
G Proteins ◽  
Diabetic Rat ◽  
Rat Retina ◽  
Visual Abnormalities

Subcellular Localization and Characterization of Nucleoside Diphosphate Kinase in Rat Retina: Effect of Diabetes

1998 ◽  
Vol 18 (4) ◽  
pp. 187-198 ◽  
Author(s):  
Anjaneyulu Kowluru ◽  
Renu A. Kowluru
Keyword(s):  
G Protein ◽  
G Proteins ◽  
Kinase Activity ◽  
Critical Role ◽  
Nucleoside Diphosphate Kinase ◽  
Diabetic Rat ◽  
Ndp Kinase ◽  
Rat Retina ◽  
Nucleotide Triphosphates

Nucleoside diphosphate kinase (NDP kinase) catalyzes the transfer of terminal phosphate from nucleotide triphosphates (e.g. ATP) to nucleotide diphosphates (e.g. GDP) to yield nucleotide triphosphates (e.g. GTP). Since guanine nucleotides play critical role(s) in GTP-binding protein (G-protein)-mediated signal transduction mechanisms in retina, we quantitated NDP kinase activity in subcellular fraction-derived from normal rat retina. A greater than 85% of the total specific activity was present in the soluble fraction, which was stimulated (up to 7 fold) by 2 mM magnesium. NDP kinase exhibited saturation kinetics towards di- and tri-phosphate substrates, and was inhibited by known inhibitors of NDP kinase, uridine diphosphate (UDP) or cromoglycate (CRG). We have previously reported significant abnormalities in the activation of G-proteins in streptozotocin (STZ)-diabetic rat retina (Kowluru et al. Diabetologia35:624–631, 1992). Since NDP kinase hasbeen implicated in direct interaction with and/or activation of various G-proteins, we quantitated both basal and magnesium-stimulated NDP kinase activity in soluble and particulate fractions of retina derived from STZ-diabetic rats to examine whether abnormalities in G-protein function in diabetes are attributable to alterations in retinal NDP kinase. There was no effect of diabetes either on the basal or the magnesium-activated retinal NDP kinase activity. This study represents the first characterization of NDP kinase activity in rat retina, and suggests that in diabetes, this enzyme may not be rate-limiting and/or causal for the observed alterations in retinal G-protein functions.

scholarly journals Early (5-Day) Onset of Diabetes Mellitus Causes Degeneration of Photoreceptor Cells, Overexpression of Incretins, and Increased Cellular Bioenergetics in Rat Retina

Cells ◽  
2021 ◽  
Vol 10 (8) ◽  
pp. 1981
Author(s):  
Jennifer O. Adeghate ◽  
Crystal D’Souza ◽  
Orsolya Kántor ◽  
Saeed Tariq ◽  
Abdul-Kader Souid ◽  
...  
Keyword(s):  
Diabetes Mellitus ◽  
Photoreceptor Cells ◽  
Diabetic Rats ◽  
Cellular Respiration ◽  
Diabetic Rat ◽  
Rat Retina ◽  
Atp Assay ◽  
Onset Of Diabetes ◽  
Cellular Bioenergetics ◽  
Glucagon Like Peptide 1

The effects of early (5-day) onset of diabetes mellitus (DM) on retina ultrastructure and cellular bioenergetics were examined. The retinas of streptozotocin-induced diabetic rats were compared to those of non-diabetic rats using light and transmission electron microscopy. Tissue localization of glucagon-like-peptide-1 (GLP-1), exendin-4 (EXE-4), and catalase (CAT) in non-diabetic and diabetic rat retinas was conducted using immunohistochemistry, while the retinal and plasma concentration of GLP-1, EXE-4, and CAT were measured with ELISA. Lipid profiles and kidney and liver function markers were measured from the blood of non-diabetic and diabetic rats with an automated biochemical analyzer. Oxygen consumption was monitored using a phosphorescence analyzer, and the adenosine triphosphate (ATP) level was determined using the Enliten ATP assay kit. Blood glucose and cholesterol levels were significantly higher in diabetic rats compared to control. The number of degenerated photoreceptor cells was significantly higher in the diabetic rat retina. Tissue levels of EXE-4, GLP-1 and CAT were significantly (p = 0.002) higher in diabetic rat retina compared to non-diabetic controls. Retinal cellular respiration was 50% higher (p = 0.004) in diabetic (0.53 ± 0.16 µM O2 min−1 mg−1, n = 10) than in non-diabetic rats (0.35 ± 0.07 µM O2 min−1 mg−1, n = 11). Retinal cellular ATP was 76% higher (p = 0.077) in diabetic (205 ± 113 pmol mg−1, n = 10) than in non-diabetic rats (116 ± 99 pmol mg−1, n = 12). Thus, acute (5-day) or early onslaught of diabetes-induced hyperglycemia increased incretins and antioxidant levels and oxidative phosphorylation. All of these events could transiently preserve retinal function during the early phase of the progression of diabetes.

Antioxidants attenuate early upregulation of vascular endothelial growth factor (VEGF) in the diabetic rat retina

2000 ◽  
Vol 50 ◽  
pp. 359-360
Author(s):  
Irina G Obrosova ◽  
Lamia Fathallah ◽  
Alexander Kennedy ◽  
Robert N Frank ◽  
Martin J Stevens
Keyword(s):  
Vascular Endothelial Growth Factor ◽  
Growth Factor ◽  
Diabetic Rat ◽  
Vascular Endothelial ◽  
Rat Retina ◽  
Endothelial Growth Factor

scholarly journals Vol. 7 (2008) 864–874 Targets of Tyrosine Nitration in Diabetic Rat Retina

2008 ◽  
Vol 7 (6) ◽  
pp. 1188-1189
Author(s):  
Xianquan Zhan ◽  
Yunpeng Du ◽  
John S. Crabb ◽  
Xiaorong Gu ◽  
Timothy S. Kern ◽  
...  
Keyword(s):  
Diabetic Rat ◽  
Tyrosine Nitration ◽  
Rat Retina

scholarly journals The acute effects of different spironolactone doses on cardiac function in streptozotocin-induced diabetic rats

2017 ◽  
Vol 95 (11) ◽  
pp. 1343-1350
Author(s):  
Aleksandra Vranic ◽  
Stefan Simovic ◽  
Petar Ristic ◽  
Tamara Nikolic ◽  
Isidora Stojic ◽  
...  
Keyword(s):  
Diabetes Mellitus ◽  
Systolic Function ◽  
Diabetic Rats ◽  
Diabetic Rat ◽  
Albino Rats ◽  
Acute Administration ◽  
Rat Hearts ◽  
Patients With Diabetes ◽  
Streptozotocin Induced Diabetes ◽  
Wistar Albino Rats

Currently, cardiovascular diseases are the leading cause of global mortality, while diabetes mellitus remains an important cause of cardiovascular morbidity. A recent study showed that patients with diabetes mellitus treated with mineralocorticoid receptor antagonists have improved coronary microvascular function, leading to improved diastolic dysfunction. In this study, we evaluated the influence of acute administration of spironolactone on myocardial function in rats with streptozotocin-induced diabetes mellitus, with special emphasis on cardiodynamic parameters in diabetic rat hearts. The present study was carried out on 40 adult male Wistar albino rats (8 weeks old). Rats were randomly divided into 4 groups (10 animals per group): healthy rats treated with 0.1 μmol/L of spironolactone, diabetic rats treated with 0.1 μmol/L of spironolactone, healthy rats treated with 3 μmol/L of spironolactone, and diabetic rats treated with 3 μmol/L of spironolactone. Different, dose-dependent, acute responses of spironolactone treatment on isolated, working diabetic and healthy rat heart were observed in our study. In healthy rats, better systolic function was achieved with higher spironolactone dose, while in diabetic rats, similar effects of low and high spironolactone dose were observed.

scholarly journals FTIR Spectroscopic Investigation of Mineral Structure of Streptozotocin Induced Diabetic Rat Femur and Tibia

2003 ◽  
Vol 17 (2-3) ◽  
pp. 627-633 ◽  
Author(s):  
Handan Boyar ◽  
Belma Turan ◽  
Feride Severcan
Keyword(s):  
Diabetes Mellitus ◽  
Insulin Dependent Diabetes Mellitus ◽  
Insulin Dependent Diabetes ◽  
Dependent Diabetes Mellitus ◽  
Diabetic Rat ◽  
Carbonate Content ◽  
Diabetic Patients ◽  
Type I ◽  
Mineral Density ◽  
Insulin Dependent

Diabetes mellitus (DM) can be accepted as a heterogenous multi organ disorder that can affect various systems of the human body. Disorders include retinopathy, neuropathy, cardiomyopathy, musculoskeletal abnormalities such as diminished bone formation and bone healing retardation. Low bone mineral density is often mentioned as a complication for patients with insulin dependent diabetes mellitus (type I DM). Streptozotocin (STZ) induced diabetic rats are good models for investigation of the complications of insulin dependent diabetes. In the present study, the effects of STZ induced diabetes on the mineral environment of rat bones namely femur and tibia were studied by Fourier transform infrared (FTIR) spectroscopic technique. The results revealed that mineral crystal sizes increased and carbonate content decreased for diabetic femur and tibia. These changes can be due to the formation of osteoporosis which is widely seen in diabetic patients.

Response of Small Heat Shock Proteins in Diabetic Rat Retina

2013 ◽  
Vol 54 (12) ◽  
pp. 7674 ◽  
Author(s):  
Vadde Sudhakar Reddy ◽  
Ganugula Raghu ◽  
Singareddy Sreenivasa Reddy ◽  
Anil Kumar Pasupulati ◽  
Palla Suryanarayana ◽  
...  
Keyword(s):  
Heat Shock ◽  
Heat Shock Proteins ◽  
Small Heat Shock Proteins ◽  
Diabetic Rat ◽  
Rat Retina ◽  
Shock Proteins

scholarly journals Effect of diabetes mellitus on cementum periodontal interface in Streptozotocin-induced diabetic rat model

2018 ◽  
Vol 4 (2) ◽  
pp. 181-188 ◽  
Author(s):  
Medhat Ahmed El-Zainy ◽  
Ahmed Mahmoud Halawa ◽  
Fatma Adel Saad
Keyword(s):  
Diabetes Mellitus ◽  
Rat Model ◽  
Diabetic Rat ◽  
Diabetic Rat Model

scholarly journals Diabetes mellitus increased integrins gene expression in rat endometrium at the time of embryo implantation

2019 ◽  
Author(s):  
Abbas Bakhteyari ◽  
Yasaman Zarrin ◽  
Parvaneh Nikpour ◽  
Zeinab Sadat Hosseiny ◽  
Zeinab Sadat Hosseiny ◽  
...  
Keyword(s):  
Gene Expression ◽  
Diabetes Mellitus ◽  
Group Treatment ◽  
Embryo Implantation ◽  
Treated Group ◽  
Diabetic Rats ◽  
Diabetic Rat ◽  
Control Group ◽  
Genes Expression ◽  
Normal Menstrual Cycle

Background: Diabetes mellitus deeply changes the genes expression of integrin (Itg) subunits in several cells and tissues such as monocytes, arterial endothelium, kidney glomerular cells, retina. Furthermore, hyperglycemia could impress and reduce the rate of successful assisted as well as non-assisted pregnancy. Endometrium undergoes thorough changes in normal menstrual cycle and the question is: What happens in the endometrium under diabetic condition? Objective: The aim of the current study was to investigate the endometrial gene expression of α3, α4, αv, Itg β1 and β3 subunits in diabetic rat models at the time of embryo implantation. Materials and Methods: Twenty-eight rats were randomly divided into 4 groups: control group, diabetic group, pioglitazone-treated group, and metformin-treated group. Real-time PCR was performed to determine changes in the expression of Itg α3, α4, αv, β1, and β3 genes in rat’s endometrium. Results: The expression of all Itg subunits increased significantly in diabetic rats’ endometrium compared with control group. Treatment with pioglitazone significantly reduced the level of Itg subunits gene expression compared with diabetic rats. While metformin had a different effect on α3 and α4 and elevated these two subunits gene expression. Conclusion: Diabetes mellitus significantly increased the expression of studied Itg subunits, therefore untreated diabetes could be potentially assumed as one of the preliminary elements in embryo implantation failure.

scholarly journals Enhancement of Liver Toxicity on Diabetes Mellitus by a Universal Chemical Pollutant (Acrylonitrile) in Rats

2019 ◽  
Vol 26 (2) ◽  
pp. 9-17
Author(s):  
Sameer E. Alharthi
Keyword(s):  
Oxidative Stress ◽  
Diabetes Mellitus ◽  
Aqueous Solution ◽  
Liver Toxicity ◽  
Elevated Serum ◽  
Diabetic Rat ◽  
Control Group ◽  
Distilled Water ◽  
Serum Aminotransferase ◽  
Cyp2e1 Activity

The present study was designed to investigate potential liver damage due to acrylonitrile in Streptozotocin induced diabetes in rats. Twenty-four rats were divided into 4 treatment groups. Nondiabetic control rat receiving distilled water, non-diabetic rat receiving acrylonitrile aqueous solution (10 mg/kg/day), diabetic control rat receiving distilled water and diabetic rat receiving acrylonitrile aqueous solution. All groups received the treatment for 4 weeks. The animals were assessed for hepatoxicity markers in serum, oxidative stress markers, CYP2E1 activity and cyanide formation in tissues. Acrylonitrile significantly elevated serum aminotransferase, alanine aminotransferase, total bilirubin levels, triglycerides and total cholesterol in diabetic groups as compared to normal control group. Antioxidant markers like glutathione showed significant decline while a significant increase in malondialdehyde, superoxide dismutase and catalase in diabetic rats treated with acrylonitrile. CYP2E1 activity was observed in acrylonitrile – exposed nondiabetic and diabetic groups as compared to control. Cyanide formation was raised in both the nondiabetic and diabetic groups as compared to control group. Acrylonitriles can produce acute hepatic injury, induction of diabetes mellitus type II, and accomplish the CYP2E1 enzyme which sequentially leads to generation of oxidative stress and its metabolic product–cyanide that may potentiate the oxidative stress posing more deleterious effect.

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