Improving exercise capacity, 6 wk training tends to reduce circulating endothelin after heart transplantation

Abstract

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.

Does circulating BNP normalize after heart transplantation in patients with normal hemodynamic and right and left heart functions?

“…However, normal forearm blood flow response has also been observed (26). Similarly, endothelin has been generally reported to be elevated after heart transplantation and has been proposed to increase atrial natriuretic peptide (5, 6, 27). However, its implication in the complications occurring after heart transplantation has been debated and endothelin normalization has been observed (28).…”

l-Arginine supplementation improves exercise capacity after a heart transplant

“…Indeed, HTx endothelial dysfunction was related to the exercise capacity of patients (5,29), and LAS reduced impairments in the vascular endothelial NO pathway (6). Furthermore, LAS increased NO and decreased endothelin-1 plasma concentrations, thereby improving endothelial function and exercise capacity in heartfailure or HTx patients (21,45). Therefore, we chose to measure the NOx/endothelin balance as an endothelial biological function in our patients before and after supplementation.…”

Structural and Functional Alteration of Blood Vessels Caused by Cigarette Smoking: An Overview of Molecular Mechanisms

“…In human athletes, acute exercise (for only 30 min) transiently increases plasma ET-1 levels [107] but chronic exercise (6 weeks) significantly decreases the plasma ET-1 levels and increases production of NO [108], suggesting beneficial effects of exercise on the cardiovascular system. Cigarette smokinginduced increases in plasma ET-1 levels limit both exerciseinduced vasodilation and the blood flow redistribution to active muscles [109]. A recent study designed to investigate whether physical activity influences peripheral blood flow in chronic smokers reports that basal femoral artery blood flow was ~50% higher in physically active smokers compared with sedentary smokers [27].…”