Effects Of The Inhibition Of NF-κB On TLR4 Expression In Left Ventricular Myocyte Of Goldblatt Rats

Objective: In this study, the expression of Toll like receptor 4(TLR4) was observed in the hypertrophic left ventricular myocytes ofrenovascular hypertensive rats (RHR). The effects of PDTC, an inhibitor ofNF-κB, on the expression of TLR4 was examined, so as to investigate therelationship between TLR4 and left ventricular hypertrophy, as well as theimpact of NF-κB activity on the expression of TLR4. Methods: Forty male Sprague-Dawley(SD) rats were randomlydivided into untreated hypertension group (H group, n=13) , PDTCtreatment group (P group, n=14) and sham operation group (C group, n=13).The Goldblatt model of renovascular hypertension was operated on Hgroup and P group. At the same time, C group performed a sham procedure,which included the entire surgery procession with exception of arteryclipping, was applied in control rats. P group was injected PDTC200mg·kg-1·d-1 by SC, as H group and C group received the same dosage ofsaline. The tail cuff blood pressure was detected every week, andechocardiography was performed before operation and death in each group.All rats were killed eight weeks after operation, and the samples of the leftventricle were collected and weighted. In the left ventricle, the expressionof NF-κB was examined by Immunohistochemistry and TLR4 was detectedby Western blot. Results: PDTC significantly decreased blood pressure,LVMI,RWTand MESS after six weeks injection. Immunohistochemical analysisdemonstrated that the positive immunoreactivity of NF-κB in the nucleiof hypertrophic cardiomyocytes was more considerable than in P group andC group (P<0.01). The expression of TLR4 was consistent with NF-κB. Conclusions: (1) The expression of TLR4 and NF-κB enhanced inthe hypertrophic cardiomyocytes in Goldblatt rats. (2) PDTC can not onlyinhibit NF-κB, but also suppress the expression of TLR4. (3) TLR4signaling pathway may play an important role in the development of leftventricular hypertrophy.