Oplastin time (aPTT), prothrombin time (PT), von Willebrand factor (vWf) and Methyl 2-((4-nitro-1h-pyrazol-1-yl)methyl)benzoate fibrinogen. Plasma D-Dimer was measured using an immunometric flow-through principle (D-Dimer Single Test, NycoCard READER II, Medinor A/S) according to manufacturer's instructions. Pooled plasma samples from five healthy dogs with known values, confirmed through serial measurements, were used as internal quality control material for the plasma based coagulation assays. TEG analyses were performed on citrated plasma samples as previously described [18], using a computerized thromboelastograph (TEG 5000 Hemostasis Analyzer System, Haemonetics) with continuous data acquisition. In brief, samples were thawed in a water bath at 37 , and activated using a solution of recombinant human tissue factor (TF) (Innovin, Dade Behring) at a final TF dilution of 1:50,000 [18]. The parameters chosen for further evaluation were R (reaction time), split point (SP), angle () and maximum amplitude (MA). The TEG analyses were run for at least 60 minutes. All assays were calibrated and controlled according to the manufacturers' recommendations. The PubMed ID:https://www.ncbi.nlm.nih.gov/pubmed/9625274 results were analyzed using GraphPad Prism version 4.01 for Windows (GraphPad Software). To evaluate if a change in hemostatic capacity or thyroid hormones was induced by training and/or exercise, the differences in parameters across the states were calculated (i.e. trained 4 months compared to untrained; and trained 4 months + 68 km run compared to trained 4 months). If differences were normally distributed, a student's t-testtesting deviation of mean from zero was performed. If a distribution was not normally distributed, a Wilcoxon signed rank test was performed to test if median was different from zero. To evaluate if there was a correlation between the changes in hemostatic parameters and the changes in thyroid hormone concentrations, a spearman 6-(Thiophen-3-yl)pyridin-3-amine correlation analysis was performed. If a correlation was demonstrated, a linear regression analysis was implemented. The significance level was set to P < 0.05 in all tests.Results The median of values, mean of difference and standard deviations of the clotting times, fibrinogen, vWf and the four TEG parameters (R, SP, and MA), platelet counts and CRP as well as serum thyroid hormone concentrations, for all three sample sets are summarized in Table 1. Exercise (trained 4 months + 68 km run) induced significant changes in R, SP, , MA, vWf, PT, fibrinogen and CRP. A significant change in concentration of thyroid hormones T4, fT4 and TSH was observed to be induced both by training for 4 months and after exercise. Training for 4 months also induced statistical significant changes of aPTT, PT, fibrinogen and MA. D-dimer could not be measured after exercise in several samples (12/20) due to lipemia, and this parameter was omitted from further analysis. No changes in platelet concentration were observed. Hematocrit was measured and was not correlated to the other parameters. A significant correlation between training-induced changes in T4 and aPTT (r = 0.53, P =0.02) and fT4 and aPTT (r = 0.52, P =0.02) were observed, as well as between TSH and fibrinogen (r = -0.61, P =0.005). Correlation between exercise-induced changes in T4 and PT (r = -0.49, P =0.03) was also observed. PubMed ID:https://www.ncbi.nlm.nih.gov/pubmed/15127947 The subsequent linear regression revealed significant linear correlation between training-induced changes of T4, fT4 and aPTT, and between TSH and fibrinogen and also between exercise-induced changes of T4 and PT Figure 1 (a-d).