THE EFFECT OF HEMIPLEGIA ON PLASMA ENDOTHELIN LEVELS IN THE ELDERLY

Endothelin is a potent endothelium-derived vasoconstrictor peptide. It s plasma levels fluctuate in relation to a variety of physiological an d pathophysiological conditions. It has been reported that in hemipleg ic patients blood pressure may be increased or decreased in the plegic arm according to the tone, spastic or flaccid, respectively, of the a rm. To elucidate the pathophysiological significance of endothelin in hemiplegia blood pressure alterations, we measured the plasma endothel in levels of twelve elderly patients, both in the plegic and unaffecte d arm. Seven of them were affeted by spastic and five of them by flacc id hemiplegia, based on haemorrhagic or ischemic stroke, Plasma endoth elin concentrations were significantly higher (p<0.05) in the plegic a rms (4.84+/-1.66 pg/ml) than in the unaffected ones (4.48+/-1.67 pg/ml ) of patients independent of the spastic or flaccid tone. The increase d level of plasma endothelin in the plegic arm suggests that endotheli n does not take part in the hemiplegia blood pressure alterations. End othelin could nevertheless be involved in the regulation of the vessel wall tension and may operate in blood volume homeostasis by mantainin g the strict relationship between the venous wall and the intravascula r volume.