Antioxidant effects of statins have been implicated in the reduction in microvascular permeability and edema formation in experimental and clinical studies. Bradykinin (Bk)-induced increases in microvascular permeability are potentiated by IL-1β; however, no studies have examined the protection afforded by statins against microvascular hyperpermeability. We investigated the effects of simvastatin pretreatment on albumin–fluorescein isothiocyanate conjugate (FITC-albumin) permeability in post-capillary venules in rat cremaster muscle. Inhibition of nitric oxide synthase with L-NAME (10µM) increased basal permeability to FITC-albumin, which was abrogated by superoxide dismutase and catalase. Histamine-induced (1 µM) permeability was blocked by L-NAME but unaffected by scavenging reactive oxygen species with superoxide dismutase (SOD) and catalase. In contrast, bradykinin-induced (1–100 nM) permeability increases were unaffected by L-NAME but abrogated by SOD and catalase. Acute superfusion of the cremaster muscle with IL-1β (30 pM, 10 min) resulted in a leftward shift of the bradykinin concentration–response curve. Potentiation by IL-1β of bradykinin-induced microvascular permeability was prevented by the nicotinamide adenine dinucleotide phosphate oxidase (NADPH oxidase) inhibitor apocynin (1 µM). Pretreatment of rats with simvastatin (5 mg·kg−1, i.p.) 24 h before permeability measurements prevented the potentiation of bradykinin permeability responses by IL-1β, which was not reversed by inhibition of heme oxygenase-1 with tin protoporphyrin IX (SnPP). This study highlights a novel mechanism by which simvastatin prevents the potentiation of bradykinin-induced permeability by IL-1β, possibly by targeting the assembly of NADPH oxidase subunits. Our findings highlight the therapeutic potential of statins in the prevention and treatment of patients predisposed to inflammatory diseases.
Coronary artery embolism is a rare cause of acute myocardial infarction, attributed to approximately 10% of all paradoxical embolisms. It is a condition that should be considered in patients who present with chest pain and have a low overall risk of coronary heart disease. A major risk of coronary artery embolism is the existence of a patent foramen ovale (PFO), which can be shown on bubble transthoracic echocardiography. Here we describe a case report of a 68-year-old Caucasian lady who presented with recurrent episodes of myocardial infarction secondary to a paradoxical coronary artery embolism which was likely due to a PFO. We emphasize the need for more research on the role of PFO percutaneous device closure compared to just medical therapy in those with recurrent episodes of acute myocardial infarction secondary to paradoxical coronary artery embolism. This, in turn, should provide clearer guidance in managing such patients with high risk of mortality.
Anomalous Left Coronary Artery from the Pulmonary Artery (ALCAPA) is a rare coronary artery anomaly which accounts for 0.25–0.5% of all congenital cardiac diseases, where most die within the first year of life. We present a case report of a 50-year-old lady who presented to hospital with persistent palpitations. Her admission electrocardiogram found her to be in Atrial Fibrillation (AF). She was rate-controlled and subsequently discharged. Despite that, she represented with further episodes of AF and was referred for an outpatient transthoracic echocardiogram. This revealed a dilated right coronary artery, retrograde flow in the left coronary artery and collateral flow in the myocardium. To investigate, the patient had undergone further imaging which confirmed the diagnosis. As such, she was later shortlisted for surgical intervention. Conclusively, our case exemplifies the role of multimodal imaging to identify the features of ALCAPA and may be useful for the purposes of surgical intervention.