Fig. 4

Effects of +5.0 Gz acceleration on the plasma concentration of cardiac troponin T (cTnT) in rats with (n = 13) and without (n = 14) anti-G equipment (Ant-G). More than a week prior to the experiment, an arterial catheter was implanted aseptically and plugged out with heparinized saline and a metal plug. A blood sample was obtained before and 3 h later after the centrifuge (+5.0 Gz during 15 s) or sham centrifuge. The plasma cTnT level was determined by the electrochemiluminescence immunoassay method. Filled circle obtained values, filled square not detectable levels, Before and Bef before acceleration, After and Aft after acceleration. **p < 0.01 by one-factor ANOVA with the Tukey–Kramer test. Significant difference was detected in mean plasma cTnT levels between the ‘After’-of-the-sham-centrifuge group and the ‘After’-of- +5.0 Gz-without Anti-G group (0.04 ± 0.05 vs. 0.14 ± 0.11 ng/ml), and between the ‘After’-of-the- +5.0 Gz-with-Anti-G group and the ‘After’-of- +5.0 Gz-without-Anti-G’ group (0.03 ± 0.05 vs. 0.14 ± 0.11 ng/ml). The data shows that +5.0 Gz acceleration increased plasma cTnT level when without anti-G equipment, but did not when with anti-G equipment, indicating that +5.0 Gz acceleration without anti-G equipment may leave some microinjuries in the myocardium [15, 16]