scholarly journals Early elevation of left ventricular end diastolic pressure in spontaneously hypertensive rats comparing with normotensive rats. Experimental study

2005 ◽  
Vol 18 (5) ◽  
pp. A183-A183
Author(s):  
R SOLE ◽  
J CANAS ◽  
M MARTINEZ ◽  
C PARDINES
2015 ◽  
Vol 117 (suppl_1) ◽  
Author(s):  
Jaqueline S da Silva ◽  
Roberto T Sudo ◽  
Roberto Debom ◽  
Eliezer J Barreiro ◽  
Carlos A Fraga ◽  
...  

Severe ventricular dysfunction is observed in spontaneously hypertensive rats (SHR) submitted to myocardial infarction (MI). The present work evaluates the cardioprotective effects of oral administration of a novel agonist of adenosine A2A receptor, LASSBio-294, in infarcted SHR. Methods: Male SHR (12-14 wks old) were randomly divided into groups: sham and infarcted (MI) which were either treated orally with vehicle or LASSBio-294 (10 mg/kg) for 28 days. Before and after the animals were treated with LASSBio-294, cardiac function and exercise capacity were evaluated through the echocardiography and treadmill test. Mean blood pressure (MBP), left ventricular end diastolic pressure (LVEDP) and negative dP/dt were also determined. Fibrosis in heart sections were detected using H&E staining. Immunohistochemical staining for TNF-alpha and SERCA2a in LV tissues were observed. Results: MI in SHR reduced the running distance from 257.9 ± 13.2 to 39.0 ± 4.4 m which normalized to 296.0 ± 26.4 m after treatment with LASSBio-294. Reduced anterior wall thickness was observed after MI (0.51 ± 0.14 mm) which was prevented with treatment (1.65 ± 0.21 mm). Ratio of early and late transmitral filling velocity was reduced from 1.48 ± 0.09 to 0.99 ± 0.04 and recovered to 1.35 ± 0.07 after treatment. MBP was reduced from 169.0 ± 5.6 to 120.4 ± 7.4 mmHg in SHR-IM treated with LASSBio-294. Increased LVEDP of 25.6 ± 3.2 observed in SHR-IM was reduced to 7.3 ± 1.0 mmHg after treatment. The -dP/dt was reduced in SHR-MI to -5698 ± 408.1 mmHg/s and returned to -7894 ± 631.6 mmHg/s after LASSBio-294 treatment. There was an increase in collagen deposition after MI (from 14.5 ± 3.5 to 59.8 ± 5.4 %) which was prevented with LASSBio-294 treatment (29.5 ± 2.2 %). Increase of positive staining for TNF-α was observed in SHR-MI (from 9.5 ± 1.0 to 32.3 ± 2.1%) which recovered in SHR-MI treated group (14.4 ± 1.3%). Also, the expression of SERCA2a was reduced in ventricular muscle from SHR-IM (from 68.7 ± 5.1 to 21.4 ± 2.3 %) which partially recovered to 40.6 ± 1.19% with LASSBio-294 treatment. Conclusion: LASSBio-294 reduced exercise intolerance, prevented cardiac remodeling and diastolic dysfunction in infarcted SHR.


Circulation ◽  
2007 ◽  
Vol 116 (suppl_16) ◽  
Author(s):  
SureshVarma Penumathsa ◽  
Srikanth Koneru ◽  
Mahesh Thirunavukkarasu ◽  
Lijun Zhan ◽  
Nilanjana Maulik

Hypertension the major risk factor for many cardiovascular diseases is a result of multiple causes along with excessive generation of reactive oxygen species resulting in imbalance of redox status. Thioredoxin-1 (Trx-1) is a redox regulatory multifunctional protein with anti-inflammatory, anti-apoptotic and antioxidant effects. In the present study we investigated the therapeutic potential of Adeno-Trx-1 in spontaneously hypertensive rats (SHR). The rats were assigned to four different groups (n = 24) such as (1) normotensive Wistar Kyoto (WKY) (2) SHR (3) SHR +Adeno-Lac-Z (SHRLac-Z) and (4) SHR +Adeno-Trx-1 (SHRTrx-1). Echo-guided gene delivery to the anterior wall of left ventricle was performed using 1x109 pfu of adenovirus constructed with Trx-1 and Lac-Z. Two days after injection of adeno virus, the hearts were subjected to permanent left anterior descending coronary artery occlusion (MI). Left ventricular functions by Echocardiography were examined after 30 days of MI as the significant changes in left ventricle were observed after 4 weeks of MI. Decreased left ventricular inner diameter (7 vs 9 mm) and increased ejection fraction (52 vs 42 %), fractional shortening (28 vs 22 %) was observed in SHRTrx-1 compared to SHR. Infarct size, cardiomyocyte apoptosis and protein expression profiles (by Confocal and Western blot analysis) were observed at predetermined time points i.e after 24 and 48 hours of MI respectively. Decreased infarct size (52% vs 67%), cardiomyocyte apoptosis by TUNEL assay (161 vs 240) and increased expression of Trx-1 and HO-1 were observed in SHRTrx-1 compared to SHR. Confocal results were also confirmed by Western blot analysis. Results documented increased expression of Trx-1 (1.8 fold) and HO-1 (1.4 fold) in SHRTrx-1 as compared to SHR. In addition, we have also observed increased expression of anti-apoptotic protein Bcl-2 (1.7 fold) in SHRTrx-1 treated group compared SHR. Thus our results demonstrate for the first time that the cardioprotective effect of Adeno-Trx-1 therapy in SHR is Trx-1/HO-1/Bcl-2 mediated and may represent a novel mechanism for therapy against hypertension induced post infarction heart failure.


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