BackgroundPostconditioning (PostC) inhibits myocardial apoptosis after ischemia-reperfusion (I/R) injury. The JAK2-STAT3 pathway has anti-apoptotic effects and plays an essential role in the late protection of preconditioning. Our aim was to investigate the anti-apoptotic effect of PostC after prolonged reperfusion and the role of the JAK2-STAT3 pathway in the anti-apoptotic effect of PostC.MethodsWistar rats were subjected to 30 minutes ischemia and 2 or 24 hours (h) reperfusion, with or without PostC (three cycles of 10 seconds reperfusion and 10 seconds reocclusion at the onset of reperfusion). Separate groups of rats were treated with a JAK2 inhibitor (AG490) or a PI3K inhibitor (wortmannin) 5 minutes before PostC. Immunohistochemistry was used to analyze Bcl-2 protein levels after reperfusion. mRNA levels of Bcl-2 were detected by qRT-PCR. TTC staining was used to detect myocardial infarction size. Myocardial apoptosis was evaluated by TUNEL staining. Western-blot was used to detect p-STAT3 and p-Akt levels after reperfusion.ResultsThere was more myocardial apoptosis at 24 h vs 2 h after reperfusion in all groups. PostC significantly reduced myocardial apoptosis and elevated Bcl-2 levels at both 2 and 24 hours after reperfusion. PostC increased p-STAT3 and p-Akt levels after reperfusion. Administration of AG490 reduced p-STAT3 and p-Akt levels and attenuated the anti-apoptotic effect of PostC. Wortmannin also reduced p-Akt levels and attenuated the anti-apoptotic effect of PostC but had no effect on p-STAT3 levels. AG490 abrogated the up-regulation of Bcl-2 by PostC.ConclusionPostC may reduce myocardial apoptosis during prolonged reperfusion via a JAK2-STAT3-Bcl-2 pathway. As a downstream target of JAK2 signaling, activation of PI3K/Akt pathway may be necessary in the protection of PostC.

Background Superior mesenteric artery embolism (SMAE) is a rare cause of acute abdomen, and the fatality rate is extremely high if it is not diagnosed and treated in time. Due to the lack of knowledge and experience of nonspecialist physicians, it is easy to misdiagnose. Radiofrequency ablation (RFA) has become the first-line treatment strategy for atrial fibrillation (AF). Thromboembolic events are some of the major complications after RFA, whereas SMAE is rarely reported. Case presentation A 70 year-old woman with paroxysmal AF who regularly took anticoagulant drugs for 3 months experienced abdominal pain after RFA. At the outset, she was misdiagnosed as mechanical intestinal obstruction. When the patient presented with blood in the stool, abdominal enhancement computed tomography was conducted and showed a small bowel perforation. Immediate laparotomy was performed, and the final diagnosis was SMAE. Conclusion It is suggested that for unexplained abdominal pain after RFA of AF, the possibility of SMAE should be considered, and a targeted examination should be carried out in time to confirm the diagnosis and give appropriate treatment.