Methylprednisolone Protects Cardiac Pumping Mechanics from Deteriorating in Lipopolysaccharide-Treated Rats
نویسندگان
چکیده
It has been shown that a prolonged low-dose corticosteroid treatment attenuates the severity of inflammation and the intensity and duration of organ system failure. In the present study, we determined whether low-dose methylprednisolone (a synthetic glucocorticoid) can protect male Wistar rats against cardiac pumping defects caused by lipopolysaccharide-induced chronic inflammation. For the induction of chronic inflammation, a slow-release ALZET osmotic pump was subcutaneously implanted to infuse lipopolysaccharide (1 mg kg(-1) d(-1)) for 2 weeks. The lipopolysaccharide-challenged rats were treated on a daily basis with intraperitoneal injection of methylprednisolone (5 mg kg(-1) d(-1)) for 2 weeks. Under conditions of anesthesia and open chest, we recorded left ventricular (LV) pressure and ascending aortic flow signals to calculate the maximal systolic elastance (E max) and the theoretical maximum flow (Q max), using the elastance-resistance model. Physically, E max reflects the contractility of the myocardium as an intact heart, whereas Q max has an inverse relationship with the LV internal resistance. Compared with the sham rats, the cardiodynamic condition was characterized by a decline in E max associated with the increased Q max in the lipopolysaccharide-treated rats. Methylprednisolone therapy increased E max, which suggests that the drug may have protected the contractile status from deteriorating in the inflamed heart. By contrast, methylprednisolone therapy considerably reduced Q max, indicating that the drug may have normalized the LV internal resistance. In parallel, the benefits of methylprednisolone on the LV systolic pumping mechanics were associated with the reduced cardiac levels of negative inotropic molecules such as peroxynitrite, malondialdehyde, and high-mobility group box 1 protein. Based on these data, we suggested that low-dose methylprednisolone might prevent lipopolysaccharide-induced decline in cardiac intrinsic contractility and LV internal resistance, possibly through its ability to reduce the aforementioned myocardial depressant substances. However, since our results were obtained in anesthetized open-chest rats, extrapolation to what may occur in conscious intact animals should be done with caution.
منابع مشابه
Acetyl-l-Carnitine and Oxfenicine on Cardiac Pumping Mechanics in Streptozotocin-Induced Diabetes in Male Wistar Rats
INTRODUCTION In the treatment of patients with diabetes, one objective is an improvement of cardiac metabolism to alleviate the left ventricular (LV) function. For this study, we compared the effects of acetyl-l-carnitine (one of the carnitine derivatives) and of oxfenicine (a carnitine palmitoyltransferase-1 inhibitor) on cardiac pumping mechanics in streptozotocin-induced diabetes in male Wis...
متن کاملp-Coumaric acid protects cardiac function against lipopolysaccharide-induced acute lung injury by attenuation of oxidative stress
Objective(s): Acute lung injury (ALI) has a high mortality rate and is characterized by damage to pulmonary system giving rise to symptoms such as histological alteration, lung tissue edema and production of proinflammatory cytokine. p-Coumaric acid (p-CA), as a phenolic compound, that is found in many types of fruits and vegetables has been reported to exhibit a thera...
متن کاملBetaine protects cerebellum from oxidative stress following levodopa and benserazide administration in rats
Objective(s): The aim of the present study was to evaluate antioxidant and methyl donor effects of betaine in cerebellum following levodopa and benserazide administration in rats. Materials and Methods: Sprague-Dawley male rats were treated with levodopa (LD), betaine (Bet), levodopa plus betaine (LD/Bet), levodopa plus benserazide (LD/Ben), levodopa plus betaine-benserazide (LD/Bet-Ben), and t...
متن کاملA combination of methylprednisolone and quercetin is effective for the treatment of cardiac contusion following blunt chest trauma in rats
Cardiac contusion is a potentially fatal complication of blunt chest trauma. The effects of a combination of quercetin and methylprednisolone against trauma-induced cardiac contusion were studied. Thirty-five female Sprague-Dawley rats were divided into five groups (n=7) as follows: sham, cardiac contusion with no therapy, treated with methylprednisolone (30 mg/kg on the first day, and 3 mg/kg ...
متن کاملEffect of concomitant administration of eicosapentaenoic acid and alendronate on bone changes due to methylprednisolone in rats
One of the main limitations of glucocorticoid therapy is its negative effects on bones. The aim of this study was to determine the effects of concurrent administration of eicosapentaenoic acid (EPA) and alendronate on bone changes induced by glucocorticoid treatment in rats. Thirty six male Wistar rats, who were 2.5 months of age, were divided equally into six groups and treated with normal sal...
متن کامل