A sensitive radioimmunoassay measuring endothelin-like immunoreactivity in human plasma : comparison of levels in patients with essential hypertension and normotensive control subjects
Davenport, A.; Ashby, M.J.; Easton, P.; Ella, S.; Bedford, J.; Dickerson, J.E.C.; Nunez, D.J.; Capper, S.J.; Brown, M.J.
Citation: Davenport , A , Ashby , M J , Easton , P , Ella , S , Bedford , J , Dickerson , J E C , Nunez , D J , Capper , S J & Brown , M J 1990 , ' A sensitive radioimmunoassay measuring endothelin-like immunoreactivity in human plasma : comparison of levels in patients with essential hypertension and normotensive control subjects ' Clinical Science , vol 78 , pp. 261-264 .
1. A radioimmunoassay has been developed for measuring endothelin-like immunoreactivity in human plasma using an antibody raised against endothelin-1 which also cross-reacts with big endothelin-1 and endothelin-2 but not endothelin-3. 2. The sensitivity of the assay was 1 fmol/tube with inter- and intra-assay coefficients of variation of 13% and 9%, respectively. Cross-reactivity with endothelin-3 and non-endothelin peptides was less than 1%. 3. Endothelin-like immunoreactivity was present in the plasma of hypertensive patients (n = 25) at a concentration of 5.7 +/- 0.5 pmol/l (mean +/- SEM), which was not significantly different from that of age-matched control subjects (5.1 +/- 0.5 pmol/l). At these levels, endothelin-1 is unlikely to function as a circulating hormone. 4. Within the normotensive group, the concentration of endothelin-like immunoreactivity in plasma was positively correlated with mean arterial blood pressure, but in hypertensive patients it showed a significant negative correlation.
Original article can be found at: http://www.clinsci.org/cs/078/cs0780261.htm Copyright The Biochemical Society and the Medical Research Society [Full text of this article is not available in the UHRA]