scholarly journals Anti‐Inflammatory and Antiarrhythmic Effects of Beta Blocker in a Rat Model of Rheumatoid Arthritis

2020 ◽  
Vol 9 (18) ◽  
Author(s):  
Ting‐Tse Lin ◽  
Yen‐Ling Sung ◽  
Jhen‐Yang Syu ◽  
Kia‐Yuan Lin ◽  
Hung‐Jui Hsu ◽  
...  
Keyword(s):  
Rheumatoid Arthritis ◽  
Ventricular Arrhythmia ◽  
Action Potential ◽  
Action Potential Duration ◽  
Cardiac Fibrosis ◽  
Optical Mapping ◽  
Ex Vivo ◽  
Electrical Remodeling ◽  
Propranolol Treatment ◽  
Anti Inflammatory

Background Patients with rheumatoid arthritis are at twice the risk of ventricular arrhythmia and sudden cardiac death as the general population. We hypothesize that β‐blocker treatment of rheumatoid arthritis is antiarrhythmic by producing synergistic anticatecholaminergic and anti‐inflammatory effects. Methods and Results Collagen‐induced arthritis (CIA) was induced in Lewis rats by immunization with type II collagen in Freund's incomplete adjuvant. The treatment with propranolol (4 mg/kg) started on the first day of immunization. We evaluated the ventricular vulnerability to ventricular arrhythmia using in vivo programmed stimulation and performed ex vivo optical mapping to measure the electrical remodeling of the heart. The ventricular tissue was further processed for immunohistochemical staining and protein array analysis. The assessment of ventricular vulnerability showed that the number and duration of the induced ventricular arrhythmia episodes were increased in CIA rats, which were improved with propranolol treatment. The sympathovagal index and the plasma level of catecholamines significantly increased in CIA rats, whereas the use of propranolol attenuated sympathetic hyperactivity. In the optical mapping study, electrical remodeling, characterized by prolonged action potential duration, slow conduction velocity, and steepened action‐potential duration restitution, were noted in CIA rats and reversed in the propranolol‐treatment group. The propranolol treatment was associated with decreases in paw thickness, fewer inflammatory cell infiltrations in the heart, reduced levels of cardiac inflammatory cytokines, and less cardiac fibrosis as compared with the CIA group. Conclusions CIA increased ventricular arrhythmia vulnerability through sympathetic hyperinnervation and proarrhythmic ventricular electrophysiological remodeling. Treatment with propranolol in CIA rats was both anti‐inflammatory and antiarrhythmic.

scholarly journals Global Deletion of 11β-HSD1 Prevents Muscle Wasting Associated with Glucocorticoid Therapy in Polyarthritis

2021 ◽  
Vol 22 (15) ◽  
pp. 7828
Author(s):  
Justine M. Webster ◽  
Michael S. Sagmeister ◽  
Chloe G. Fenton ◽  
Alex P. Seabright ◽  
Yu-Chiang Lai ◽  
...  
Keyword(s):  
Rheumatoid Arthritis ◽  
Skeletal Muscle ◽  
Chronic Inflammation ◽  
Muscle Atrophy ◽  
Muscle Wasting ◽  
Ex Vivo ◽  
Glucocorticoid Therapy ◽  
Knock Out ◽  
Fiber Size ◽  
Anti Inflammatory

Glucocorticoids provide indispensable anti-inflammatory therapies. However, metabolic adverse effects including muscle wasting restrict their use. The enzyme 11beta-hydroxysteroid dehydrogenase type 1 (11β-HSD1) modulates peripheral glucocorticoid responses through pre-receptor metabolism. This study investigates how 11β-HSD1 influences skeletal muscle responses to glucocorticoid therapy for chronic inflammation. We assessed human skeletal muscle biopsies from patients with rheumatoid arthritis and osteoarthritis for 11β-HSD1 activity ex vivo. Using the TNF-α-transgenic mouse model (TNF-tg) of chronic inflammation, we examined the effects of corticosterone treatment and 11β-HSD1 global knock-out (11βKO) on skeletal muscle, measuring anti-inflammatory gene expression, muscle weights, fiber size distribution, and catabolic pathways. Muscle 11β-HSD1 activity was elevated in patients with rheumatoid arthritis and correlated with inflammation markers. In murine skeletal muscle, glucocorticoid administration suppressed IL6 expression in TNF-tg mice but not in TNF-tg11βKO mice. TNF-tg mice exhibited reductions in muscle weight and fiber size with glucocorticoid therapy. In contrast, TNF-tg11βKO mice were protected against glucocorticoid-induced muscle atrophy. Glucocorticoid-mediated activation of catabolic mediators (FoxO1, Trim63) was also diminished in TNF-tg11βKO compared to TNF-tg mice. In summary, 11β-HSD1 knock-out prevents muscle atrophy associated with glucocorticoid therapy in a model of chronic inflammation. Targeting 11β-HSD1 may offer a strategy to refine the safety of glucocorticoids.

An amebic anti-inflammatory peptide down-regulates ex vivo IL-1β expression in patients with rheumatoid arthritis

2012 ◽  
Vol 8 (6) ◽  
pp. 315-320 ◽  
Author(s):  
Juan R. Velázquez ◽  
Lizeth Garibay-Martínez ◽  
Pedro Martínez-Tejada ◽  
Yelda A. Leal
Keyword(s):  
Rheumatoid Arthritis ◽  
Ex Vivo ◽  
Anti Inflammatory

Reverse use dependence of calcium sensitizer levosimendan on action potential duration shortening prevents ventricular arrhythmia during therapeutic hypothermia

2020 ◽  
Vol 41 (Supplement_2) ◽  
Author(s):  
Y.C Hsieh ◽  
C.H Li ◽  
J.C Lin ◽  
C.J Weng ◽  
Y.S Chien ◽  
...  
Keyword(s):  
Ventricular Arrhythmia ◽  
Action Potential ◽  
Therapeutic Hypothermia ◽  
Action Potential Duration ◽  
Heart Failure Treatment ◽  
Novel Approach ◽  
Mapping System ◽  
Diastolic Interval ◽  
K Current ◽  
Calcium Sensitizer

Abstract Background Therapeutic hypothermia (TH) increases the risk of ventricular arrhythmia (VA) by prolonging action potential duration (APD) and steepening the APD restitution (APDR). The calcium sensitizer levosimendan, a medication for heart failure treatment, has been reported to shorten APD by enhancing ATP-sensitive K current and affect the APDR. Purpose We hypothesized that levosimendan might shorten the already prolonged APD particularly at long pacing cycle length (PCL), thus decreases the maximal slope of APDR, and prevent VA during TH. Methods Langendorff-perfused isolated rabbit hearts were subjected to 15-min TH (30°C) followed by 30-min treatment with levosimendan (0.5 μM, n=9) or vehicle (n=8). Using an optical mapping system, APD was evaluated by S1 pacing and APDR curve was plotted using APD70 versus diastolic interval. Ventricular fibrillation (VF) inducibility was evaluated by burst pacing for 30 s at the shortest PCL that achieved 1:1 ventricular capture. Results The APD was shortened from 259±8 ms at TH to 241±18 ms after levosimendan infusion at long PCL of 400 ms (p=0.024). However, at short PCL of 280 ms, the APD was not changed before (194±19) and after (188±23) levosimendan during TH (p=0.61). Levosimendan decreases the maximal slope of APDR curve from 1.99±0.65 at TH to 1.41±0.32 after adding levosimendan (p=0.034). The VF inducibility was decreased by levosimendan from 39±30% at 30°C to 14±12% with levosimendan (p=0.023). In control hearts, the maximal slope of APDR (p=0.75) and VF inducibility (p=0.12) were not changed by vehicle during TH. Conclusion Levosimendan might protect the hearts against VA during TH by shortening APD at long PCL and flattening the APDR. Enhancing ATP-sensitive K current with levosimendan during TH might be a novel approach to prevent VA during TH. Funding Acknowledgement Type of funding source: None

Concurrent increases in post-pacing action potential duration and contractility predict occurrence of ventricular arrhythmia

2020 ◽  
Vol 472 (12) ◽  
pp. 1783-1791
Author(s):  
Chih-Min Liu ◽  
Feng-Zhi Lin ◽  
Yao-Chang Chen ◽  
Yung-Kuo Lin ◽  
Yen-Yu Lu ◽  
...  
Keyword(s):  
Ventricular Arrhythmia ◽  
Action Potential ◽  
Action Potential Duration

An amebic anti-inflammatory peptide down-regulates ex vivo IL-1β expression in patients with rheumatoid arthritis

2012 ◽  
Vol 8 (6) ◽  
pp. 315-320
Author(s):  
Juan R. Velázquez ◽  
Lizeth Garibay-Martínez ◽  
Pedro Martínez-Tejada ◽  
Yelda A. Leal
Keyword(s):  
Rheumatoid Arthritis ◽  
Ex Vivo ◽  
Anti Inflammatory

The ex-vivo effects of thyroid status and extracellular calcium concentration on rat atrial and ventricular electrophysiology

1988 ◽  
Vol 66 (1) ◽  
pp. 90-94 ◽  
Author(s):  
R. W. Gristwood ◽  
A. L. Rothaul
Keyword(s):  
Action Potential ◽  
Action Potential Duration ◽  
Calcium Concentration ◽  
Ex Vivo ◽  
Additional Treatment ◽  
Extracellular Calcium ◽  
Krebs Solution ◽  
Thyroid Status ◽  
Extracellular Calcium Concentration ◽  
Atrial Electrophysiology

The purpose of this study was to explore the relationship between the thyroid status and both ventricular and atrial electrophysiology in the rat. The study was extended to consider the effects of altering the extracellular calcium concentration. The work was performed in two sections. First, hypothyroid animals were compared with euthyroid (untreated animals); second, hypothyroid animals were compared with hyperthyroid animals. Rats were rendered hypothyroid by pretreatment with the goitrogen methimazole and hyperthyroid by additional treatment with triiodothyronine. Action potential recordings were obtained using standard microelectrode techniques. Action potential measurements were made initially in a Krebs solution to which had been added 2.55 mM calcium (higher Ca Krebs solution) and at the end of each experiment after stabilization with Krebs solution to which had been added 1.28 mM calcium (lower Ca Krebs solution). Assessment of the change in action potential duration on transition from higher to lower Ca Krebs solution revealed that the euthyroid preparations demonstrated less prolongation of action potential duration than the hypothyroid group, and the hyperthyroid group showed hardly any response to reduction in calcium concentration.

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