Our previous study demonstrated that flavone inhibits vascular contractions by decreasing the phosphorylation levelof the myosin phosphatase target subunit (MYPT1). In the present study, we hypothesized that flavone attenuates vascular contractions through the inhibition of the RhoA/Rho kinase pathway. Rat aortic rings were denuded of endothelium, mounted in organ baths, and contracted with either 30 nM U46619 (a thromboxane A2 analogue) or 8.0 mM NaF 30 min after pretreatment with either flavone (100 or 300 micrometer) or vehicle. We determined the phosphorylation level of the myosin light chain (MLC20), the myosin phophatase targeting subunit 1 (MYPT1) and the protein kinase C-potentiated inhibitory protein for heterotrimeric myosin light chain phophatase of 17-kDa (CPI17) by means of Western blot analysis. Flavone inhibited, not only vascular contractions induced by these contractors, but also the levels of MLC20 phosphorylation. Furthermore, flavone inhibited the activation of RhoA which had been induced by either U46619 or NaF. Incubation with flavone attenuated U46619-or NaF-induced phosphorylation of MYPT1(Thr855) and CPI17(Thr38), the downstream effectors of Rho-kinase. In regards to the Ca2+-free solution, flavone inhibited the phosphorylation of MYPT1(Thr855) and CPI17(Thr38), as well as vascular contractions induced by U46619. These results indicate that flavone attenuates vascular contractions, at least in part, through the inhibition of the RhoA/Rho-kinase pathway.
15-Hydroxy-11 alpha,9 alpha-(epoxymethano)prosta-5,13-dienoic Acid ; Animals ; Baths ; Blotting, Western ; Contracts ; Endothelium ; Flavones ; Myosin Light Chains ; Myosin-Light-Chain Phosphatase ; Myosins ; Phosphorylation ; Phosphotransferases ; Protein Kinases ; Rats ; rho-Associated Kinases ; Thromboxane A2 ; Vasodilation

It was hypothesized that NaF induces calcium sensitization in Ca2+-controlled solution in permeabilized rat mesenteric arteries. Rat mesenteric arteries were permeabilized with beta-escin and subjected to tension measurement. NaF potentiated the concentration-response curves to Ca2+ (decreased EC50 and increased E(max)). Cumulative addition of NaF (4.0, 8.0 and 16 mM) also increased vascular tension in Ca2+-controlled solution at pCa 7.0 or pCa 6.5, but not at pCa 8.0. NaF-induced vasocontraction and GTPgammaS-induced vasocontraction were not additive. NaF-induced vasocontraction at pCa 7.0 was inhibited by pretreatment with Rho kinase inhibitors H1152 or Y27632 but not with a MLCK inhibitor ML-7 or a PKC inhibitor Ro31-8220. NaF induces calcium sensitization in a Ca2+-dependent manner in beta-escin-permeabilized rat mesenteric arteries. These results suggest that NaF is an activator of the Rho kinase signaling pathway during vascular contraction.
Amides ; Animals ; Azepines ; Calcium ; Contracts ; Escin ; Indoles ; Mesenteric Arteries ; Naphthalenes ; Passive Cutaneous Anaphylaxis ; Pyridines ; Rats ; rho-Associated Kinases ; Sodium ; Sodium Fluoride

Objective : To analyze the association between multiple loci of genes and the risk of early⁃onset pre⁃ eclampsia (EOPE) with pregnancy induced hypertension. Methods : Among 382 EOPE patients who had lived in Yanbian area for more than 10 years , 192 patients were randomly selected as case group. At the same time , 192 cases of natural delivery in the hospital were randomly selected as the control group. PCR⁃RFLP method was used to determine the specific genotype and allele distribution information , and non⁃conditional Logistic method was used to obtain odds ratio (OR) and 95% confidence interval (CI) to confirm the risk of various genotypes. Results : There were two alleles of T and C at the GRB2 rs8082005 locus , TC , TT , and CC genotypes. There were two alleles of T and C at the RXRA rs3849222 locus , TC , TT , and CC genotypes. Through unconditional logistic regression analysis , in the GRB2 rs8082005 locus , compared with the TT genotype , the CC genotype was more susceptible to EOPE ( OR = 3. 155 , 95% CI = 1. 513 - 6. 579 , P = 0. 002) . In the explicit model , compared to patients with TT+ TC genotype , patients with CC genotype increased the risk of EOPE ( OR = 3. 000 , 95% CI = 1. 495 - 6. 022 , P = 0. 002) . In the RXRA rs3849222 locus , compared with the CC genotype , the TT genotype was more susceptible to EOPE ( OR = 2. 031 , 95% CI = 1. 077 - 3. 820 , P = 0. 028) . In the invisible model , compared to patients with CC + CT genotype , patients with TT genotype had an increased risk of EOPE ( OR = 2. 549 , 95% CI = 1. 421 - 4. 573 , P = 0. 002) . Conclusion There is a significant correlation between single nucleotide polymorphism (SNP) at the GRB2 rs8082005 and RXRA rs3849222 loci and the risk of EOPE in pregnant women with gestational hypertension in Yanbian area.