Treadmill Exercise Alleviates Aging-induced Apoptosis in Rat Cardiac Myocytes

SummaryBackgroundThe incidence and prevalence of heart failure increases with age. Cardiomyocyte apoptosis contributes to the pathogenesis of heart failure. In the end-stage of human heart failure, increased cardiomyocyte apoptosis is observed. Exercise training is one of the nonpharmacological treatments for chronic heart failure.MethodsIn the present study, we investigated the effect of treadmill exercise on the aging-induced apoptosis within cardiac myocytes in relation to the expression of heat shock protein 70 (HSP70) using rats. Terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling (TUNEL) staining and Western blotting for the expression of Bcl-2, Bax, HSP70, and phosphorylated p38 (p-p38) in the cardiac myocardium were conducted.ResultsAging induced apoptosis in the myocardium, which was confirmed by increased TUNEL-positive cells and the enhancement of Bax. Expression of HSP70 was suppressed and p-p38 expression was enhanced by aging. Treadmill exercise alleviated aging-induced apoptosis with enhancing HSP70 expression and suppressing p-p38 expression in the cardiac myocytes.ConclusionBased on the present results, it can be inferred that treadmill exercise can provide a cardioprotective effect on aging-induced apoptosis through the enhancement of HSP70 expression in the heart. Thus, regular exercise may be a useful strategy for preventing heart problems in the elderly

Effect of Total Leaf Numbers on the Growth and Fruit Quality in Muskmelon Plants Showing Leaf Yellowing Symptoms

This study was conducted to evaluate the influence of total leaf numbers on the growth, net formation of fruits, and occurrence of leaf yellowing symptoms (LYS) in muskmelon plants. The growth and development of LYS on muskmelon plants having 25, 30, and 35 fully expanded leaves on the vine were compared to those of the control plant having 20 leaves. Plant height, leaf area, root fresh weight, and root dry weight increased as the number of leaves increased. Plants with 35 leaves showed the greatest plant growth. Net photosynthetic rate was positively related to increasing leaf numbers with plants having over 25 leaves showing the greatest photosynthetic rates. On the other hand, there were no significant differences in chlorophyll content and root activity among treatments with different leaf numbers. The ratio of LYS infection was also greater in plants having 25-30 leaves, than in those having leaf numbers. Plants with different leaf numbers and LYS infection showed a variation in fruit quality, although LYS did not significantly affect fruit quality except net index. The plants having 20 leaves that showed LYS developed fruits that had significantly smaller flesh (mesocarp) thickness than, the plants having greater numbers of leaves. The higher sugar contents of fruits were found in the plants having 35 leaves whether they showed LYS (12.1°Bx) or not (12.5°Bx). Therefore, leaving more than 25 healthy leaves per plant was recommended for minimizing damage from LYS.OAIID:oai:osos.snu.ac.kr:snu2015-01/104/0000027607/11ADJUST_YN:NEMP_ID:A075898DEPT_CD:517CITE_RATE:0FILENAME:(이희주)effect_of_total_leaf_numbers_on_the_growth_and_fruit_quality_in_muskmelon_plants_showing_leaf_yell··.pdfDEPT_NM:식물생산과학부CONFIRM:

Vardenafil Enhances Oxytocin Expression in the Paraventricular Nucleus without Sexual Stimulation

PurposeOxytocin is associated with the ability to form normal social attachments. c-Fos is an immediate early gene whose expression is used as a marker for stimulus-induced changes in neurons. The effect of phosphodiesterase-5 (PDE-5) inhibitors on oxytocin activation in the brain without sexual stimuli has not yet been reported. In the present study, we investigated the effects of vardenafil on oxytocin and c-Fos expression in the paraventricular nucleus (PVN) of conscious rats.MethodsMale Sprague-Dawley rats weighing 300±10 g were divided into 6 groups (n=5 in each group): the control group, the 1-day-0.5 mg/kg, the 1-day-1 mg/kg, the 1-day-2 mg/kg, the 3-day-1 mg/kg, and the 7-day-1 mg/kg vardenafil administration group. The experiment was conducted without sexual stimulation. Vardenafil was orally administered. The animals in the control group received an equivalent amount of distilled water orally. The expression of oxytocin and c-Fos in the PVN was detected by immunohistochemistry.ResultsOxytocin expression in the PVN was increased by 1 day administration of 2 mg/kg vardenafil, and this effect of vardenafil appeared in a duration-dependent manner. c-Fos in the oxytocin neurons of the PVN was increased by 1 day administration of 2 mg/kg vardenafil, and this effect of vardenafil also appeared in a duration-dependent manner. These results showed that vardenafil augments the expression of oxytocin with activation of oxytocin neurons in the PVN.ConclusionsIn this study, we showed that the PDE-5 inhibitor, vardenafil directly enhances oxytocin expression and also activates oxytocin neurons in the PVN, which indicates that vardenafil may exert positive effects on affiliation behavior and social interaction

Six-Month Comparison of Coronary Endothelial Dysfunction Associated With Sirolimus-Eluting Stent Versus Paclitaxel-Eluting Stent

ObjectivesThis study was designed to investigate whether endothelial dysfunction is related to drug-eluting stent (DES) implantation at 6 months after stenting.BackgroundCurrent available DES could delay vessel healing and subsequently impair endothelial function.MethodsEndothelial function was estimated at 6-month follow-up in 75 patients (31 men, mean age 62.1 years) with a DES (39 sirolimus-eluting stents [SES], 36 paclitaxel-eluting stents [PES]), and 10 patients with a bare-metal stent (BMS) to the left anterior descending artery, by incremental acetylcholine (Ach) infusion (20 μg/min, 50 μg/min, 100 μg/min) and nitrate (200 μg/min) into the left coronary ostium. Vascular responses were quantitatively measured in arterial segments 5 mm proximal and distal to DES and compared with corresponding segments in the BMS group and midsegments in the left circumflex artery as a reference nonstented artery. All antianginal agents were withheld for at least 72 h before coronary angiography.ResultsGreater vasoconstriction to Ach was observed in both the SES and PES groups than in the BMS group or control segments of left circumflex artery. Vasoconstriction to Ach was more prominent in arterial segments distal to stents in both SES and PES groups compared with those in the BMS group (p < 0.001). The degree of vasoconstriction to Ach was similar between the SES and PES groups. Endothelium-independent vasodilatation to nitrate did not differ significantly between the study groups.ConclusionsAbnormal vasoconstriction to Ach was found in the SES and PES groups, especially in arterial segments distal to DES at 6 months after stenting, which suggests that DES has a potential long-term adverse effect on local coronary endothelial dysfunction

Bare-metal stents versus drug-eluting stents in large (≥3.5mm) single coronary artery: Angiographic and clinical outcomes at 6 months

SummaryBackgroundAlthough drug-eluting stents (DES) have been shown to dramatically reduce restenosis and improve the rate of event-free survival in large randomized trials, the benefit of DES appears to be limited to restenosis. In large arteries, it is not clear which type of stent is more superior in angiographic and clinical outcomes between DES and bare-metal stents (BMS). We compared the angiographic and clinical outcomes of DES versus BMS in large arteries (≥3.5mm).MethodTwo hundred and forty patients from March 2002 to March 2007 received stents; 196 patients were treated with DES (44.9% sirolimus-eluting stents; 43.9% paclitaxel-eluting stents; 11.2% zotarolimus-eluting stents) and 44 with cobalt–chromium BMS for single de novo lesions in a large vessel. All subjects received aspirin, clopidogrel, and/or cilostazol as the standard antiplatelet regimen. The angiographic and clinical outcomes were evaluated at 6 months.ResultsFor the baseline characteristics, there were no significant differences between the DES and BMS groups. In addition, for the initially implanted stent there was no difference in the length, stent diameter, and lesion site between the two groups. After 6 months, the follow-up angiogram showed that in-stent diameter restenosis and late loss was more common with BMS than DES (39±21% vs. 19±17%, p=0.007; 1.44±0.83mm vs. 0.62±0.58mm, p=0.009, respectively). However, the target-lesion revascularization/target-vessel revascularization, and total major adverse cardiac events showed no significant differences between the groups (5.3% vs. 3.6%, p=0.62; 5.3% vs. 4.6%, p=0.86, respectively).ConclusionThe DES and cobalt–chromium BMS placed in large coronary arteries showed equally favorable 6-month clinical outcomes, although the 6-month angiographic results appeared more favorable in the DES group than in the BMS group

The Significance of the J-Curve in Hypertension and Coronary Artery Diseases

The J-curve effect describes an inverse relation between low blood pressure (BP) and cardiovascular complications. This effect is more pronounced in patients with preexisting coronary artery disease (CAD), hypertension or left ventricular hypertrophy (LVH). The recent large clinical outcomes trials have observed a J-curve effect between a diastolic BP of 70-80 mmHg as well as a systolic BP <130 mmHg. The J-curve phenomenon does not appear in stroke or renal disease. This is because the coronary arteries are perfused during diastole, but the cerebral and renal perfusion mainly occurs in systole. Therefore, caution should be taken to maintain the diastolic blood pressure (DBP) at minimum of 70 mmHg and possibly to maintain the DBP between 80-85 mmHg in patients with severe LVH, CAD or vascular diseases. BP control in high-risk elderly patients should be carefully done as undergoing aggressive therapy to lower the systolic blood pressure below 140 mmHg can cause cardiovascular complications due to the severely reduced DBP and increased pulse pressure