Effect of propofol on right ventricular hypertrophy induced by pulmonary arterial hypertension in rats / 中华麻醉学杂志

ABSTRACT

Objective:To evaluate the effect of propofol on right ventricular hypertrophy induced by pulmonary arterial hypertension (PAH) in rats.Methods:Twenty-two clean-grade healthy adult male Wistar rats, weighing 250-280 g, were divided into 3 groups using a random number table method: control group (group C, n=8), PAH group (group PH, n=6) and propofol group (group P, n=8). In PH and P groups, monocrotaline 60 mg/kg was injected intraperitoneally to establish the model of PAH, while the equal volume of normal saline was administered in group C. Propofol 100 mg/kg was injected intraperitoneally twice a week for 6 consecutive weeks starting from 2 weeks after establishment of the model in group P. The weight of rats was measured before establishment of model and after administration, and the weight difference (△BW=weight after administration-weight before administration) was calculated.At the end of administration, the right ventricular end-diastolic dimension (RVEDD), right ventricular wall thickness in diastole (RVWTd), intraventricular septum in diastole (IVSd), left ventricular posterior wall in diastole (LVPWd) and maximal velocity of pulmonic valve (PV) were measured using cardiac ultrasound.The animals were then sacrificed, and the lungs and hearts were removed for examination of the pathological changes (after haematoxylin and eosin staining) and for determination of the degree of myocardial fibrosis in right ventricular (by Masson staining), expression of interleukin-6 (IL-6) and tumor necrosis factor-alpha (TNF-α) in lung tissues and myocardial tissues of the right ventricle (by immunohistochemistry). Results:Compared with group C, △BW and PV were significantly decreased, RVWTd, IVTd and RVEDD were increased, the thickness of the wall of pulmonary arterioles and myocardial cell penetration area in right ventricular were increased, the expression of IL-6 and TNF-α in lung tissues and myocardial tissues of right ventricle was up-regulated ( P<0.05 or 0.01), inflammatory cell infiltration and structural disorders were found in lung tissues, and intercellular spaces were widened, and the myocardial tissue was extensively fibrotic in group PH.Compared with group PH, △BW and PV were significantly increased, RVWTd, IVTd and RVEDD were decreased, the thickness of the wall of pulmonary arterioles and myocardial cell penetration area (the area of cardiomyocytes in which the nucleus located in the middle) were decreased, the expression of IL-6 and TNF-α in lung tissues and myocardial tissues of right ventricle was down-regulated ( P<0.05 or 0.01), inflammatory cell infiltration, structural disorders, intercellular spaces and degree of fibrosis were improved in group P. Conclusion:Propofol can alleviate right ventricular hypertrophy induced by PAH, and the mechanism is probably related to reduction of inflammatory responses in rats.