Improving exercise capacity, 6 wk training tends to reduce circulating endothelin after heart transplantation.
Short-term survival is no longer the pivotal issue after heart transplantation but, most heart-transplant (Htx) patients still present with increased circulating endothelin-1 (ET) and reduced exercise capacity. ET-1 limits both exercise-induced vasodilation and blood flow redistribution toward acting muscles and might be accessible to training. This study was performed to investigate the effect of training on ET-1 and whether an eventual training-induced improvement in exercise capacity may be related to reduced baseline or exercise circulating ET-1 in Htx patients. Five Htx patients performed a maximal bicycle exercise test and an endurance exercise test before and after a training program of 18 exercises sessions during 6 wk. ET-1 was determined by radioimmunoassay at rest, end endurance exercise and 30 min recovery, before and after training. Training improved significantly Htx's maximal oxygen uptake (+13.1 +/- 4.8%; p < 0.05) and also reduced significantly the endurance exercise-induced heart rate increase. Resting ET-1 was increased in Htx (5.98 +/- 1.88 vs. 1.61 +/- 0.25 pmol/L in controls; p < 0.01) but although ET-1 modulation might participate in training-induced beneficial effects, training failed to modulate either resting or exercise ET-1 plasma level. Training-induced improvement in exercise capacity might not mainly due to decreased ET-1 after heart transplantation. Further supporting the usefulness of training, these preliminary data suggest that improved exercise capacity may not be mainly due to decreased ET-1 in Htx patients. Further, larger scale studies will be needed to investigate whether an impaired nitric oxide pathway stimulation might explain such results and whether a longer training program can reduce local ET-1, arising from working muscles after heart transplantation.
Doutreleau
Stèphane
S
Service de Physiologie Clinique et d'Explorations Fonctionnelles, Service de Chirurgie Cardiovasculaire et UPRES EA 3072, Hôpitaux Universitaires et Faculté de Médecine, Strasbourg, France. stephane.doutreleau@physio-ulp.u-strasbg.fr
Piquard
François
F
Lonsdorfer
Evelyne
E
Rouyer
Olivier
O
Lampert
Eliane
E
Mettauer
Bertrand
B
Richard
Ruddy
R
Geny
Bernard
B
D000328:Adult; D019332:Endothelin-1 / Q000097:blood*; D015444:Exercise; D017079:Exercise Tolerance; D016027:Heart Transplantation; D006801:Humans; D008297:Male; D013997:Time Factors
D019332:Endothelin-1