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Full-Text Articles in Diseases

Impaired Overload-Induced Hypertrophy Is Associated With Diminished Mtor Signaling In Insulin-Resistant Skeletal Muscle Of The Obese Zucker Rat, Anjaiah Katta, Sudarsanam Kundla, Sunil Kakarla, Miaozong Wu, Jacqueline Fannin, Satyanarayana Paturi, Hua Liu, Hari Addagarla, Eric Blough Feb 2013

Impaired Overload-Induced Hypertrophy Is Associated With Diminished Mtor Signaling In Insulin-Resistant Skeletal Muscle Of The Obese Zucker Rat, Anjaiah Katta, Sudarsanam Kundla, Sunil Kakarla, Miaozong Wu, Jacqueline Fannin, Satyanarayana Paturi, Hua Liu, Hari Addagarla, Eric Blough

Eric Blough

Recent data have suggested that insulin resistance may be associated with a diminished ability of skeletal muscle to undergo hypertrophy (Paturi S, Gutta AK, Kakarla SK, Katta A, Arnold EC, Wu M, Rice KM, Blough ER. J Appl Physiol 108: 7–13, 2010). Here we examine the effects of insulin resistance using the obese Zucker (OZ) rat with increased muscle loading on the regulation of the mammalian target of rapamycin (mTOR) and its downstream signaling intermediates 70-kDa ribosomal protein S6 kinase (p70S6k), ribosomal protein S6 (rpS6), eukaryotic elongation factor 2 (eEF2), and eukaryotic initiation factor 4E-binding protein 1 (4E-BP1). Compared with …


Diabetes Alters Vascular Mechanotransduction: Pressure-Induced Regulation Of Mitogen Activated Protein Kinases In The Rat Inferior Vena Cava, Kevin M. Rice, Devashish H. Desai, Sunil K. Kakarla, Anjaiah Katta, Deborah L. Preston, Paulette Wehner, Eric R. Blough Jan 2013

Diabetes Alters Vascular Mechanotransduction: Pressure-Induced Regulation Of Mitogen Activated Protein Kinases In The Rat Inferior Vena Cava, Kevin M. Rice, Devashish H. Desai, Sunil K. Kakarla, Anjaiah Katta, Deborah L. Preston, Paulette Wehner, Eric R. Blough

Eric Blough

Background Diabetes mellitus is an important risk factor for increased vein graft failure after bypass surgery. However, the cellular and molecular mechanism(s) underlying vessel attrition in this population remain largely unexplored. Recent reports have suggested that the pathological remodeling of vein grafts may be mediated by mechanically-induced activation of the mitogen activated protein kinase (MAPK) signaling pathways and the MAPK-related induction of caspase-3 activity. On the basis of these findings, we hypothesized that diabetes may be associated with alterations in how veins "sense" and "respond" to altered mechanical loading. Methods Inferior venae cavae (IVC) from the non-diabetic lean (LNZ) and …


Age-Associated Changes In Hearts Of Male Fischer 344/Brown Norway F1 Rats, Ernest M. Walker Jr., Michael S. Nillas, Elsa I. Mangiarua, Sylvestre Cansino, Ryan G. Morrison, Romaine R. Perdue, William E. Triest, Gary L. Wright, Mark Studeny, Paulette Wehner, Kevin M. Rice, Eric R. Blough Jan 2013

Age-Associated Changes In Hearts Of Male Fischer 344/Brown Norway F1 Rats, Ernest M. Walker Jr., Michael S. Nillas, Elsa I. Mangiarua, Sylvestre Cansino, Ryan G. Morrison, Romaine R. Perdue, William E. Triest, Gary L. Wright, Mark Studeny, Paulette Wehner, Kevin M. Rice, Eric R. Blough

Eric Blough

Aging is associated with left ventricular hypertrophy, dilatation, and fibrosis of the heart. The Fischer 344/Brown Norway F1 (F344/BNF1) rat is recommended for age-related studies by the National Institutes on Aging because this hybrid rat lives longer and has a lower rate of pathological conditions than inbred rats. However, little is known about age-associated changes in cardiac and aortic function and structure in this model. This study evaluated age-related cardiac changes in male F344/BNF1 rats using ECHO, gross, and microscopic examinations. Rats aged 6-, 30-, and 36-mo were anesthetized and two-dimensional ECHO measurements, two-dimensional guided M-mode, Doppler M-mode, and other …


Acetaminophen Protects Against Iron-Induced Cardiac Damage In Gerbils, Ernest M. Walker Jr., Christopher P. Epling, Cordel Parris, Silvestre Cansino, Protip Ghosh, Devashish H. Desai, Ryan G. Morrison, Gary L. Wright, Paulette Wehner, Elsa I. Mangiarua, Sandra M. Walker, Eric R. Blough Jan 2013

Acetaminophen Protects Against Iron-Induced Cardiac Damage In Gerbils, Ernest M. Walker Jr., Christopher P. Epling, Cordel Parris, Silvestre Cansino, Protip Ghosh, Devashish H. Desai, Ryan G. Morrison, Gary L. Wright, Paulette Wehner, Elsa I. Mangiarua, Sandra M. Walker, Eric R. Blough

Eric Blough

There are few effective agents that safely remove excess iron from iron-overloaded individuals. Our goal was to evaluate the iron-removing effectiveness of acetaminophen given ip or orally in the gerbil iron-overload model. Male gerbils were divided into 5 groups: saline controls, iron-overloaded controls, iron-overloaded treated with ip acetaminophen, iron-overloaded treated with oral acetaminophen, and iron-overloaded treated with ipdeferoxamine. Iron dextran was injected iptwice/wk for 8 wk. Acetaminophen and deferoxamine treatments were given on Mondays, Wednesdays, and Fridays during the same 8 wk and continued for 4 wk after completion of iron-overloading. Echocardiograms were performed after completion of the iron-overloading and …


Diabetes Alters Contraction-Induced Mitogen Activated Protein Kinase Activation In The Rat Soleus And Plantaris, Anjaiah Katta, Deborah L. Preston, Sunil K. Kakarla, Shinichi Asano, Sarath Meduru, Sriram P. Mupparaju, Ellie Yokochi, Kevin M. Rice, Devashish H. Desai, Eric R. Blough Jan 2013

Diabetes Alters Contraction-Induced Mitogen Activated Protein Kinase Activation In The Rat Soleus And Plantaris, Anjaiah Katta, Deborah L. Preston, Sunil K. Kakarla, Shinichi Asano, Sarath Meduru, Sriram P. Mupparaju, Ellie Yokochi, Kevin M. Rice, Devashish H. Desai, Eric R. Blough

Eric Blough

The prescription of anaerobic exercise has recently been advocated for the management of diabetes; however exercise-induced signaling in diabetic muscle remains largely unexplored. Evidence from exercise studies in nondiabetics suggests that the extracellular-signal-regulated kinases (Erk1/2), p38, and c-JUN NH2-terminal kinase (Jnk) mitogen-activated protein kinases (MAPKs) are important regulators of muscle adaptation. Here, we compare the basal and the in situ contraction-induced phosphorylation of Erk1/2- p38- and Jnk-MAPK and their downstream targets (p90rsk and MAPKAP-K2) in the plantaris and soleus muscles of normal and obese (fa/fa) Zucker rats. Compared to lean animals, the time course and magnitude of Erk1/2, p90rsk and …


Deferasirox Removes Cardiac Iron And Attenuates Oxidative Stress In The Iron-Overloaded Gerbil, Rabaa Al-Rousan, Satyanarayana Paturi, Joseph Laurino, Sunil Kakarla, Anil Gutta, Ernest Walker, Eric Blough Jan 2013

Deferasirox Removes Cardiac Iron And Attenuates Oxidative Stress In The Iron-Overloaded Gerbil, Rabaa Al-Rousan, Satyanarayana Paturi, Joseph Laurino, Sunil Kakarla, Anil Gutta, Ernest Walker, Eric Blough

Eric Blough

Iron-induced cardiovascular disease is the leading cause of death in iron-overloaded patients. Deferasirox is a novel, once daily oral iron chelator that was recently approved for the treatment of transfusional iron overload. Here, we investigate whether deferasirox is capable of removing cardiac iron and improving iron-induced pathogenesis of the heart using the iron overload gerbil model. Animals were randomly divided into three groups: control, iron overload, and iron overload + deferasirox treatment. Iron-dextran was given 100 mg/kg per 5 days i.p for 10 weeks. Deferasirox treatment was taken post iron loading and was given at 100 mg/kg/day p.o for 1 …


Iron-Induced Cardiac Damage: Role Of Apoptosis And Deferasirox Intervention, Yeling Wang, Miaozong Wu, Rabaa Al-Rousan, Hua Liu, Jacqueline Fannin, Satyanarayana Paturi, Ravi Arvapalli, Anjaiah Katta, Sunil Kakarla, Kevin Rice, William Triest, Eric Blough Jan 2013

Iron-Induced Cardiac Damage: Role Of Apoptosis And Deferasirox Intervention, Yeling Wang, Miaozong Wu, Rabaa Al-Rousan, Hua Liu, Jacqueline Fannin, Satyanarayana Paturi, Ravi Arvapalli, Anjaiah Katta, Sunil Kakarla, Kevin Rice, William Triest, Eric Blough

Eric Blough

Excess cardiac iron levels are associated with cardiac damage and can result in increased morbidity and mortality. Here, we hypothesize that elevations in tissue iron can activate caspase-dependent signaling, which leads to increased cardiac apoptosis and fibrosis, and that these alterations can be attenuated by iron chelation. Using an iron-overloaded gerbil model, we show that increased cardiac iron is associated with reduced activation of Akt (Ser473 and Thr308), diminished phosphorylation of the proapoptotic regulator Bad (Ser136), and an increased Bax/Bcl-2 ratio. These iron-overload-induced alterations in Akt/Bad phosphorylation and Bax/Bcl-2 ratio were coupled with increased activation of the downstream caspase-9 (40/38- …


Acetaminophen Combinations Protect Against Iron-Induced Cardiac Damage In Gerbils, Ernest M. Walker Jr., Ryan G. Morrison, Lucy Dornon, Joseph P. Laurino, Sandra M. Walker, Mark Studeny, Paulette S. Wehner, Kevin M. Rice, Miaozong Wu, Eric R. Blough Jan 2013

Acetaminophen Combinations Protect Against Iron-Induced Cardiac Damage In Gerbils, Ernest M. Walker Jr., Ryan G. Morrison, Lucy Dornon, Joseph P. Laurino, Sandra M. Walker, Mark Studeny, Paulette S. Wehner, Kevin M. Rice, Miaozong Wu, Eric R. Blough

Eric Blough

This study tested if acetaminophen, N-methyl-D-glucamine dithiocarbamate (NMGDTC), deferoxamine, and combinations of these agents reduce excess iron content, prevent iron-induced pathology, reduce cardiac arrhythmias, and reduce mortality in iron-overloaded gerbils. Eight groups of 16 gerbils received iron dextran injections (ferric hydroxide dextran complex, 120 mg/kg, ip) or saline solution (controls) twice/wk for 8 wk. The 8 groups were treated every Monday, Wednesday, and Friday with one of the following: saline control, acetaminophen, 150 mg/kg, ip), acetaminophen (150 mg/kg, po), deferoxamine, 83 mg/kg, ip), NMGDTC (200 mg/kg, ip), or combinations of acetaminophen (75 mg/kg) with deferoxamine (42 mg/kg, each ip, separately) …