Tuesday, 19 May 2015

Telmisartan is More Effective than Taurine in Protecting High Fat Diet Induced Obesity in Rats from Hypertension, Some Metabolic, Oxidative Stress and Vascular Complications

Obesity, insulin resistance, hypertension and fatty liver, are key risk factors for vascular complications. So, this study aimed to compare between telmisartan and taurine supplementation on systolic blood pressure (SBP) in addition to some metabolic disturbances and some vascular complications in an animal model for obesity. Methods: Sixty male Wistar rats were randomly divided into six groups (n=10) for 8 weeks three groups of them received standard diet with either vehicle or taurine (3% w/v in drinking water) or telmisartan (5 mg/kg, oral) while the other three groups received high fat diet with either vehicle or taurine or telmisartan. Results: The high fat diet group had greater body weight and higher SBP as compared to control rats. Increased plasma glucose, lipid profile (except HDL), insulin, insulin resistance, MDA, and ADMA but decreased HDL, PON-1 and DDAH were also observed. Telmisartan or taurine administration resulted in decreased SBP, plasma glucose, lipid profile, insulin, insulin resistance, MDA, and ADMA but increased both plasma HDL level and PON-1activity, in addition to kidney DDAH enzyme activity with more significant effect of telmisartan than taurine. Taken together, these results support the more beneficial effect of telmisartan than taurine in obese rats by improving SBP, in addition to ameliorating hyperglycemia , dyslipidemia,( metabolic disturbances) and decreasing plasma ADMA but increasing kidney DDAH enzyme activities (vascular complications) at least in part, by improving insulin sensitivity and decreasing oxidative stress, suggesting the possible use of telmisartan as a protective strategy against vascular complications related to obesity.

Profound Shock after Initiation of Clozapine Therapy

Clozapine, a tricyclic dibenzodiazepine, is an atypical antipsychotic with dopaminergic, muscarinic, histaminic and serotonergic activity that has been used in the treatment of schizophrenia . Although prescribers commonly recognize the hematologic adverse effect agranulocytosis its cardiac side effects, such as myocarditits, are less often considered . A retrospective analysis of an Australian reporting system of patients with recent initiation of clozapine found an incidence of myocarditis about 1 in 500 young adults . Studies since this publication have demonstrated incidences ranging from 0.015% to 8.5%. This compares to an estimated incidence of clozapine-induced agranulocytosis of between 3.8% and 8% . A case definition for clozapine-related myocarditis used by Ronaldson et al described the syndrome as “any new symptoms of myocarditis within 45 days of commencing clozapine with histologic or clinical signs of cardiac dysfunction with either laboratory or radiographic evidence of myocardial pathology or congestive heart failure in the absence of alternative plausible schizophrenia”

Citation: Choi A, Sud P, Greller H (2014) Profound Shock after Initiation of Clozapine Therapy. Cardiol Pharmacol 3:118.

Monday, 18 May 2015

Preventing Recurrences: Classic and Modern Antiarrhythmic Drugs in Atrial Fibrillation

 
Medication for atrial fibrillation (AF) with antiarrhythmic drugs (AAD) has been in use for almost 100 years and today remains an essential part of the treatment in patients with this condition. The goals of drug treatment include reducing the number, duration and symptoms of atrial fibrillation episodes, reducing mortality and hospitalizations as well as improving the patients’ quality of life. AAD use is limited by adverse effects which include proarrhythmia, negative inotropic and non-cardiovascular toxicity. The efficacy of these drugs is limited, which means that there are other invasive options that are clearly more effective for symptomatic control of patients.

High Susceptibility of Atherosclerotic Coronary Arteries to the Onset of Vasospasm and Angina Pectoris-like Symptoms due to Coronary Spasm in WHHLMI Rabbits

Objectives: We examined the relationship between atherosclerosis and provocation of coronary spasm as well as influence of coronary spasm on the onset of acute ischemic myocardial disease. Methods and Results: Coronary spasm was provoked in anesthetized normal Japanese white (JW) rabbits and WHHLMI rabbits, an animal model for coronary atherosclerosis and myocardial infarction, by injecting ergonovine during the infusion of norepinephrine through a marginal ear vein. A decrease in contrast flow in the left circumflex artery was observed on coronary angiograms. Ischemic changes were observed on the electrocardiogram of 29% (2/7) of JW and 79% (27/34) of WHHLMI rabbits. The frequency of coronary spasm was significantly high in rabbits with severe coronary plaques showing diffuse lesions. In addition, the degree of contraction of coronary strips with atherosclerotic plaques was higher than that of normal coronary strips excised from JW rabbits stimulated by a combination of ergonovine and norepinephrine. Left ventricle motility in these vasospasm-positive rabbits, which was evaluated with echocardiograms was decreased by 29% following the ergonovine injection (P<0.001), and every serum ischemic marker examined markedly increased 4 hours after the provocation of vasospasm. Conclusions: The results of the present study demonstrated that atherosclerotic coronary arteries were positively related to the provocation of vasospasm, and vasospasm in severe atherosclerotic coronary segments evoked angina pectoris and/or non-fatal myocardial infarction.