Changes in Autophagy Levels in Rat Myocardium During Exercise Preconditioning-Initiated Cardioprotective Effects

Osmolarity of a fixative vehicle has long been known to have an effect on the tissue preservation. An increase in tissue osmolarity occurs in ischemia-damaged tissue and affects the morphology. In this study, we examined cellular changes in ischemic rat myocardium induced by varying fixative toxicity.Rats were sacrificed by decapitation and the hearts immediately removed and retrogradily perfused through the aorta with anoxic Kurbs-Henseleit medium. Hearts were then placed in a bag with a small amount of medium at 37°C for 90 minutes. Hearts were perfusion-fixed using 2% glutaraldehyde in 0.1 M cacodylate buffer pH -7.3 at three osmolarities. The isotonic buffer was adjusted to 311 mOsm/kg using D-manitol. Hypertonic buffers were adjusted to 375 and 400 mOsm/kg. One-half hour after perfusion fixation, the hearts were sliced and cut into small blocks and allowed to fix overnight at 4°C. Blocks were post fixed in osmium, en bloc stained in uranyl acetate, dehydrated in ethanol and embedded in Spurr medium.

Download Full-text

Sensitive Detection of the Effects of Aging in Senescent Rat Myocardium With Ultrasonic Tissue Characterization

Journal of the American College of Cardiology ◽

10.1016/s0735-1097(97)88080-1 ◽

1998 ◽

Vol 31 (2) ◽

pp. 478A

Author(s):

C Nguyen

Keyword(s):

Tissue Characterization ◽

Sensitive Detection ◽

Rat Myocardium ◽

Effects Of Aging

Download Full-text

Preinfarction Angina and Improved Reperfusion of the Infarct-related Artery

Thrombosis and Haemostasis ◽

10.1055/s-0037-1615557 ◽

1999 ◽

Vol 82 (S 01) ◽

pp. 68-72 ◽

Cited By ~ 2

Author(s):

Alessandro Sciahbasi ◽

Eugenia De Marco ◽

Attilio Maseri ◽

Felicita Andreotti

Keyword(s):

Myocardial Infarction ◽

Acute Myocardial Infarction ◽

Infarct Size ◽

Ischemic Preconditioning ◽

Early Reperfusion ◽

Vast Number ◽

Beneficial Effects ◽

Infarct Related Artery ◽

Cardioprotective Effects ◽

Collateral Vessels

SummaryPreinfarction angina and early reperfusion of the infarct-related artery are major determinants of reduced infarct-size in patients with acute myocardial infarction. The beneficial effects of preinfarction angina on infarct size have been attributed to the development of collateral vessels and/or to post-ischemic myocardial protection. However, recently, a relation has been found between prodromal angina, faster coronary recanalization, and smaller infarcts in patients treated with rt-PA: those with preinfarction angina showed earlier reperfusion (p = 0.006) and a 50% reduction of CKMB-estimated infarct-size (p = 0.009) compared to patients without preinfarction angina. This intriguing observation is consistent with a subsequent observation of higher coronary recanalization rates following thrombolysis in patients with prodromal preinfarction angina compared to patients without antecedent angina. Recent findings in dogs show an enhanced spontaneous lysis of plateletrich coronary thrombi with ischemic preconditioning, which is prevented by adenosine blockade, suggesting an antithrom-botic effect of ischemic metabolites. Understanding the mechanisms responsible for earlier and enhanced coronary recanalization in patients with preinfarction angina may open the way to new reperfusion strategies.A vast number of studies, globally involving ≈17,000 patients with acute myocardial infarction, have unequivocally shown that an infarction preceded by angina evolves into a smaller area of necrosis compared to an infarct not preceded by angina (Table 1) (1). So far, preinfarction angina has been thought to have cardioprotective effects mainly through two mechanisms: collateral perfusion of the infarctzone (2-4), and ischemic preconditioning of the myocardium (5-7). Here we discuss a further mechanism of protection represented by improved reperfusion of the infarct-related artery.

Download Full-text

Intracardiac injection of epoetin upregulates SDF-1 gene expression promoting myocardial regeneration in a rat myocardium infarction

The Thoracic and Cardiovascular Surgeon ◽

10.1055/s-2008-1037875 ◽

2008 ◽

Vol 56 (S 1) ◽

Author(s):

D Furlani ◽

C Klopsch ◽

R Gäbel ◽

K Wagner ◽

M Ugurlucan ◽

...

Keyword(s):

Gene Expression ◽

Myocardial Regeneration ◽

Rat Myocardium ◽

Myocardium Infarction ◽

Intracardiac Injection

Download Full-text

Glutamine Is Cardioprotective in Patients with Ischemic Heart Disease following Cardiopulmonary Bypass

The Heart Surgery Forum ◽

10.1532/hsf98.20111074 ◽

2011 ◽

Vol 14 (6) ◽

pp. 384 ◽

Cited By ~ 17

Author(s):

Vladimir V. Lomivorotov ◽

Sergey M. Efremov ◽

Vladimir A. Shmirev ◽

Dmitry N. Ponomarev ◽

Vladimir N. Lomivorotov ◽

...

Keyword(s):

Heart Disease ◽

Placebo Group ◽

Cardiopulmonary Bypass ◽

Ischemic Heart Disease ◽

Troponin I ◽

Left Ventricular ◽

Ischemic Heart ◽

Left Ventricular Ejection ◽

Study Group ◽

Cardioprotective Effects

Background: The aim of the present study was to investigate the cardioprotective effects of the perioperative use of N(2)-L-alanyl-L-glutamine (GLN) in patients with ischemic heart disease (IHD) who undergo their operations under cardiopulmonary bypass (CPB).Methods: This double-blind, placebo-controlled, randomized study included 50 patients who underwent cardiac surgery with CPB. Exclusion criteria were a left ventricular ejection fraction <50%, diabetes mellitus, <3 months since the onset of myocardial infarction, and emergency surgery. Patients in the study group (n = 25) received 0.4 g/kg GLN (Dipeptiven, 20% solution) per day. Patients in the control group (n = 25) were administered a placebo (0.9% NaCl). The primary end point was the dynamics of troponin I at the following stages: (1) prior to anesthesia, (2) 30 minutes after CPB, (3) 6 hours after CPB, (4) 24 hours after surgery, and (5) 48 hours after surgery. Secondary end points included measurements of hemodynamics with a Swan-Ganz catheter.Results: On the first postoperative day after the surgery, the median troponin I level was significantly lower in the study group than in the placebo group: 1.280 ng/mL (interquartile range [IQR], 0.840-2.230 ng/mL) versus 2.410 ng/mL (IQR, 1.060-6.600 ng/mL) (P = .035). At 4 hours after cardiopulmonary bypass (CPB), the median cardiac index was higher in the patients in the study group: 2.58 L/min per m2 (IQR, 2.34-2.91 L/min per m2) versus 2.03 L/min per m2 (IQR, 1.76-2.32 L/min per m2) (P = .002). The median stroke index also was higher in the patients who received GLN: 32.8 mL/m2 (IQR, 27.8-36.0 mL/m2) versus 26.1 mL/m2 (IQR, 22.6-31.8 mL/m2) (P = .023). The median systemic vascular resistance index was significantly lower in the study group than in the placebo group: 1942 dyn�s/cm5 per m2 (IQR, 1828-2209 dyn�s/cm5 per m2) versus 2456 dyn�s/cm5 per m2 (IQR, 2400-3265 dyn�s/cm5 per m2) (P = .001).Conclusion: Perioperative administration of GLN during the first 24 hours has cardioprotective effects in IHD patients following CPB. This technique enhances the troponin concentration at 24 hours after surgery and is associated with improved myocardial function.

Download Full-text

Analysis of alginate implants degradation rate in rat myocardium

Problems of Cryobiology and Cryomedicine ◽

10.15407/cryo24.02.173 ◽

2014 ◽

Vol 24 (2) ◽

pp. 173-173

Author(s):

Tatyana V. Shkand ◽

◽

Anatoliy L. Tatarets ◽

Keyword(s):

Degradation Rate ◽

Rat Myocardium

Download Full-text