Increased endothelin and creatine kinase after electrical stimulation of paraplegic muscle.

The purpose of this study was to assess changes in creatine kinase (CK) and endothelin (ET) in individuals with spinal cord injury (SCI) after computerized functional electrical stimulation leg ergometry (CFES LE). Eight subjects (7 male and 1 female) with complete spinal cord lesions (C7 to L1) completed zero-loaded CFES LE tests at baseline, after 3, 6, and 12 wk of CFES LE training (30 min, 3 times/wk), and also after detraining (DT) (n = 5). Venous blood samples were drawn 24, 48, and 72 h after CFES LE for measurement of ET and CK. The CK response was largest (peak CK) 72 h after baseline tests (28.2 +/- 6.0 to 895.7 +/- 345.9 ktals/l) and was no different from baseline by weeks 3, 6, and 12. After DT, CK was similar before and after CFES LE (153.8 +/- 19.0 and 189.7 +/- 34.5 ktals/l, respectively). CFES LE also significantly increased peak ET after baseline (from 11.7 +/- 1.5 to 18.0 +/- 2.5 pg/ml). During the subsequent training, peak ET remained significantly higher than the baseline value at weeks 3, 6, and 12 (20.2 +/- 1.8, 18.0 +/- 1.1, and 16.9 +/- 2.2 pg/ml, respectively). After DT, peak ET increased significant relationship (r = 0.44) existed between ln peak CK activity and peak ET. In summary, the increase in circulating ET in spinal cord-injured individuals may have implications for baroreceptor function and therefore blood pressure control in SCI. Further research into CFES LE, ET, and baroreceptor function in SCI is warranted.

Effects of electrical stimulation and upper body training after spinal cord injury.

The purpose of this study was to measure the cardiorespiratory improvements during the initial weeks of training in individuals with spinal cord injury (SCI). Eight adult volunteers (ages 23-41) with paraplegia (T4-L1, N = 7) and low levels of quadriplegia (C7, N = 1) participated in a 12-wk training program consisting of 6 wk of computerized functional electrical stimulation leg ergometry (CFES LE) followed by 6 wk of combined arm ergometry and CFES LE (hybrid ergometry; HE). Measures of peak oxygen consumption (pV02) and immediate post-exercise blood lactate (La-) were collected during an intermittent CFES LE graded exercise test (3-min stages; 1/8-kp increments) prior to training (0T), following 6 wk of CFES LE training (6T) and following 6 wk of HE training (12T). Voluntary arm ergometry (AE) graded exercise tests were also completed at each of 0T, 6T, and 12T, and an intermittent graded HE test was also given at 6T and 12T. Following the 6 wk of CFES LE, AE pVO2 increased from 1.14 +/- 0.09 l.min-1 to 1.39 +/- 0.172 l.min-1 (P < 0.05), and CFES LE pVO2 increased from 0.51 +/- 0.05 l.min-1 to 0.83 +/- 0.06 l.min-1 (P < 0.05). Following the 6 wk of HE, HE pVO2 increased from 1.31 +/- 0.15 l.min-1 to 1.49 +/- 0.14 l.min-1 (P < 0.05). HE pVO2 was 58%-60% higher than CFES LE pVO2 at the mid- and post-testing periods. HE pVO2 was 14% higher than AE pVO2 at the post-testing period.(ABSTRACT TRUNCATED AT 250 WORDS)