The presence of immunoreactive endothelin (ir-ET) in the tumor tissues of two cases of ectopic ACTH-secreting bronchial carcinoid tumors was studied by radioimmunoassay. The cross-reaction with big ET-1, ET-2, and ET-3 was 5%, 6%, and 6%, respectively. Tumor tissue ir-ET concentrations in two ectopic ACTH-secreting bronchial carcinoid tumors were 920 and 3,370 fmol/g wet weight, which were much higher than those in pheochromocytomas (146 ± 70 fmol/g wet weight: n = 12, mean ± SD), adrenocortical tumors (115 ± 105 fmol/g wet weight, n = 14), and normal parts of adrenal glands (82 ± 31 fmol/g wet weight, n = 12). High-performance liquid chromatography of the tumor tissue extract showed that the ir-ET was mainly eluted in the position of ET-1. Plasma levels of ir-ET in these two cases were not elevated (1.2 and 1.7 pmol/L). The findings of the present study suggest that ET-1 has local pathophysiologic roles in the tumor tissues of ectopic ACTH-secreting bronchial carcinoid tumors.
|Journal||Journal of Cardiovascular Pharmacology|
|Issue number||SUPPL. 8|
|Publication status||Published - 1993 Dec 1|
ASJC Scopus subject areas
- Cardiology and Cardiovascular Medicine