ABSTRACT
Oxytocin (OT) and its receptor (OTR) are expressed in the heart and are involved in the physiological cardiovascular functional system. Although it is known that OT/OTR signaling is cardioprotective by reducing the inflammatory response and improving cardiovascular function, the role of OT in the cardiac electrical excitation modulation has not been clarified. This study investigates the molecular mechanism of the action of OT on cardiomyocyte membrane excitation focusing on the L-type Ca2+ channel. Our methodology uses molecular biological methods and a patch-clamp technique on rat cardiomyocytes with OT, combined with several signal inhibitors and/or activators. Our results show that long-term treatment of OT significantly decreases the expression of Cav1.2 mRNA, and reduces the L-type Ca2+ channel current (ICa.L) in cardiomyocytes. OT downregulates the phosphorylated component of a transcription factor adenosine-3',5'-cyclic monophosphate (cAMP) response element binding protein (CREB), whose action is blocked by OTR antagonist and pertussis toxin, a specific inhibitor of the inhibitory GTP-binding regulators of adenylate cyclase, Gi. On the other hand, the upregulation of Cav1.2 mRNA expression by isoproterenol is halted by OT. Furthermore, inhibition of phospholipase C (PLC) was without effect on the OT action to downregulate Cav1.2 mRNA-which suggests a signal pathway of Gi/protein kinase A (PKA)/CREB mediated by OT/OTR. These findings indicate novel signaling pathways of OT contributing to a downregulation of the Cav1.2-L-type Ca2+ channel in cardiomyocytes.
ABSTRACT
Surgical adhesive agents are frequently applied to reinforce aortic sutures in cardiac and aortic surgery. They are thought to provide hemostasis and safely and effectively reduce morbidity. Complications owing to surgical glue remnants, however, have been reported. In our recent case, a surgical glue remnant was detected on the aortic valve by transesophageal echocardiography. For detection of such surgical glue remnants, and to prevent associated serious potential complications, comprehensive transesophageal echocardiography is important. If surgical glue is applied during operative procedures, the heart and aorta should be carefully examined by transesophageal echocardiography.
Subject(s)
Aortic Valve/diagnostic imaging , Tissue Adhesives/adverse effects , Aged, 80 and over , Cardiopulmonary Bypass/instrumentation , Echocardiography, Transesophageal , Female , HumansABSTRACT
BACKGROUND: Minimally invasive cardiac surgery (MICS), via minithoracotomy, is thought to be a fast track to extubation and recovery after surgery. For this, good coverage analgesia is essential. Epidural anesthesia, a standard technique for thoracic surgery, has high risk of complications, such as epidural abscess and spinal hematoma in open-heart surgery. Based on the hypothesis that continuous paravertebral block (CPVB), a less invasive regional anesthetic technique, is safe and effective in open-heart surgery, we applied CPVB to MICS with thoracotomy. FINDINGS: To assess whether CPVB could be used in open-heart surgery with fewer potential complications, we investigated our medical records of the 87 adult patients who underwent MICS at Akashi Medical Center, Hyogo, Japan, between March 2009 and May 2016. We collected data of CPVB-related complications, postextubation respiratory failure, duration of intubation, and other analgesic use from hospital clinical records. We observed no severe CPVB-related complications, such as hematoma, neuropathy, or abscess. PT-INR longer than 1.1 was associated with CPVB-related minor bleeding. Forty-three patients (47.4%) were extubated within 1 h after surgery, and there were no postextubation respiratory failures in any patients. CONCLUSIONS: We observed no cases of severe CPVB-related complications or postextubation respiratory failure in any of our patients who underwent MICS. Preoperative prolongation of PT-INR was associated with CPVB-related minor bleeding.
