Resveratrol suppresses apoptosis in intact human cardiac tissue - in vitro model simulating extracorporeal circulation.

AIM: After cardioplegia and subsequent reperfusion of the myocardium as employed in cardiac surgery, ischemia/reperfusion injury of the myocardium can induce apoptosis. The aim of this study was to evaluate the anti-apoptotic properties of resveratrol, a phenolic phytoalexin present in grape skins and especially red wines during simulated cardioplegia (cp) and reperfusion (rep) in an in-vitro microperfusion model on human myocardium, which to our knowledge has not been investigated yet. METHODS: Cardiac specimens were retrieved from the right auricle of patients undergoing elective coronary artery bypass graft before induction of cardiopulmonary bypass. Cardiac specimens, with resveratrol (10 µM) (N.=15) and w/o resveratrol (control, N.=15) were exposed in vitro to varying periods of cp/rep (30/10, 60/20, 120/40 min) in a microperfusion chamber. For detection of apoptosis anti-activated-caspase-3, PARP-1 cleavage immunostaining and real-time PCR for gene expression of cardiac cytokines like BNP, NF-κB1, NF-κB2, E-Selectin, Troponin and TNF-α were employed. CONTROL GROUP: the longer the cp/rep period lasted the higher were the rate of anti-activated-caspase-3 positive cardiomyocytes (21.26±2.07% ­ 46.56±3.2%) and of PARP1-cleavage positive cardiomyocytes (23.29±2.16% ­ 36.86±2.11%). Resveratrol group: apoptosis was suppressed significantly (P<0.05). Anti-activated-caspase-3 positive cardiomyocytes (13.45±4.35% ­ 15.3±2.97%) and PARP1-cleavage positive cardiomyocytes (9.87±2.04% ­ 11.77±3.42%). Resveratrol significantly suppressed the expression of BNP, NF-κB2, E-Selectin, Troponin and TNF-α in vitro (P<0.05). CONCLUSION: Resveratrol significantly suppresses apoptosis under our applied in vitro conditions. This finding warrants further studies aiming suppression of ischemia/reperfusion injury in clinical settings.

Suppressing apoptosis with milrinone simulating extracorporeal circulation: a pilot study.

BACKGROUND: After cardioplegia, ischemia/reperfusion injury can induce apoptosis. The aim of this study was to evaluate our ex vivo microperfusion model on human myocardium during simulated cardioplegia (cp) and reperfusion (rep). In addition, the aim was to verify the anti-apoptotic properties of the phosphodiesterase 3 inhibitor milrinone. METHODS: Cardiac biopsies were retrieved from the right auricle of patients undergoing elective CABG prior to induction of cardiopulmonary bypass. Biopsies were exposed to ex vivo conditions with varying periods of cp/rep (30/10, 60/20, 120/40 min). Group I consisted of untreated controls (n=15), Group II of treated controls who had cp/rep (n=15) while Group III had cp/rep+milrinone (n=15). For the detection of apoptosis, anti-activated caspase-3 and PARP-1 cleavage immunostaining were used. RESULTS: The percentage of apoptotic cardiomyocytes in Group I was significantly (P<0.05) lower compared to Group II, revealing a time-dependent increase. In Group III with milrinone treatment, apoptosis was significantly suppressed (P<0.05). CONCLUSIONS: Milrinone significantly suppressed apoptosis in our ex vivo setting. This finding warrants further study aiming to evaluate the potential beneficial effects of milrinone on the suppression of ischemia/reperfusion injury in a clinical setting.