38 research outputs found

    Differential characteristics of neural circulatory control : early versus late after cardiac transplantation

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    BACKGROUND: Reappearance of low-frequency (LF) (+/-0.10 Hz) oscillations in RR interval (RR) after cardiac transplantation is indicative of sympathetic efferent reinnervation. We hypothesized that restored LF oscillations in RR in heart transplant recipients (HTRs) are linked to oscillations in muscle sympathetic nerve traffic (MSNA). METHODS AND RESULTS: RR, RR variability, and MSNA were recorded 5+/-2 months (n=7, short-term HTRs) and 138+/-8 months (n=7, long-term HTRs) after heart transplantation and compared with matched hypertensive patients (n=7). A coherence function determined the coupling between LF oscillations in MSNA and RR. RR variance did not differ between short-term and long-term HTRs. However, LF variability was only 1+/-0.5 ms(2) in the short-term HTRs but was 15+/-8 ms(2) in the long-term HTRs (P<0.05). Normalized LF variability was also higher in the long-term HTRs (40+/-14 normalized unites) versus the short-term HTRs (6+/-3 normalized united, P<0.05) but did not differ from the LF variability of the hypertensive patients. Long-term HTRs were taking less cyclosporine (P<0.01) but had higher MSNA than the short-term HTRs (62+/-7 versus 31+/-7 burst/min, respectively, P<0.05). Coherence between LF oscillations in MSNA and RR was similar in the long-term HTRs (0.59+/-0.11) and the hypertensive patients (0.60+/-0.07) and was 3-fold greater than in the short-term HTRs (0.20+/-0.06, P<0.05). CONCLUSIONS: Cardiac reinnervation after long-term heart transplantation is characterized by a restoration of the coherence between LF oscillations in RR and MSNA. Higher MSNA in long-term than in short-term HTRs suggests that time elapsed after cardiac transplantation may be a major determinant of sympathetic excitation in heart transplant recipients

    Discovery of thrombin activatable fibrinolysis inhibitor (TAFI)

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    CAS: blood clotting factor 11, 9013-55-2; thrombin, 9002-04-4; tissue plasminogen activator, 105913-11-9; protein C, 60202-16-6; Carboxypeptidase U, 3.4.17.20; Protein C; Tissue Plasminogen Activator, 3.4.21.6

    Interruption of Wnt Signaling Attenuates the Onset of Pressure Overload-Induced Cardiac Hypertrophy

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    The hypertrophic response of the heart has been recognized recently as the net result of activation of prohypertrophic and antihypertrophic pathways. Here we report the involvement of the Wnt/Frizzled pathway in the onset of cardiac hypertrophy development. Stimulation of the Wnt/Frizzled pathway activates the disheveled (Dvl) protein. Disheveled subsequently can inhibit glycogen synthase kinase-3beta, a protein with potent antihypertrophic actions through diverse molecular mechanisms. In the Wnt/Frizzled pathway, inhibition of glycogen synthase kinase-3beta leads to an increased amount of beta-catenin, which can act as a transcription factor for several hypertrophy-associated target genes. In this study we subjected mice lacking the Dvl-1 gene and their wild-type littermates to thoracic aortic constriction for 7, 14, and 35 days. In mice lacking the Dvl-1 gene, 7 days of pressure overload-induced increases in left ventricular posterior wall thickness and expression of atrial natriuretic factor and brain natriuretic protein were attenuated compared with their wild-type littermates. beta-Catenin protein amount was reduced in the group lacking the Dvl-1 gene, and an increased glycogen synthase kinase-3beta activity was observed. Moreover, the increase in the amount of Ser(473)-phosphorylated Akt, a stimulator of cardiac hypertrophy, was lower in the group lacking the Dvl-1 gene. In conclusion, we have demonstrated that interruption of Wnt signaling in the mice lacking the Dvl-1 gene attenuates the onset of pressure overload-induced cardiac hypertrophy through mechanisms involving glycogen synthase kinase-3beta and Akt. Therefore, the Wnt/Frizzled pathway may provide novel therapeutic targets for antihypertrophic therapy
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