Effects of bilateral intra-PVN infusion of VIPER on gene and protein expression of pro- and anti-inflammatory cytokines and iNOS in WKY and SHR rats. (A) mRNA expression of TNF-α; (B) mRNA expression of IL1-β; (C) A representative immunoblot; (D) densitometric analysis of protein expression of TNF-α, IL1-β, IL10 and iNOS; (E) mRNA expression of IL10; and (F) mRNA expression of iNOS. Values are means ± SE. n = 8 in each group for mRNA analysis and n = 5 in each group for western blot. ***P <0.001; *P <0.05 SHR + CP versus WKY + CP; #P <0.05 SHR + VIPER versus SHR + CP: CP, control peptide; IL-1β, interleukin-1 beta; IL10, interleukin10; iNOS, inducible nitric oxide; PVN, paraventricular nucleus; SHR, spontaneously hypertensive rat; TLR4, Toll-like receptor 4; TNF-α, tumor necrosis factor-alpha; VIPER, viral inhibitory peptide of TLR4; WKY, wistar-Kyoto. Furthermore, IL-10 gene and protein expression in the PVN tissue was measured to assess the effect of TLR4 blockade on anti-inflammatory axis. A significant reduction in IL-10 gene and protein expression in the SHR + CP compared with the WKY + CP rats was evident (Figure 6 C and E). Interestingly, the SHR + VIPER group had significantly higher levels of IL-10 in comparison with the SHR + CP rats, whereas there was no difference between the WKY + CP and WKY + VIPER groups.