Reactivitatea endotelinică in vitro a arterei pulmonare s-a evaluat la 17 pacienţi cu hipertensiune arterială pulmonară (46,29±2,17 mm Hg), datele fiind comparate cu indicii arterei pulmonare preluate de la 12 pacienţi fără HAP (22,92±0,65). Răspunsul constrictor al vasului a fost semnificativ crescut în HAP ( 20-21%) la acţiunea ET-1 (1,0 nM sau 10,0 nM), ce s-a atenuat concludent, până la valori referinţă, la inhibiţia receptorilor ETA prin pretratarea acţiunii ET-1 în concentraţia joasă cu antagonistul BQ-123. Inhibiţia receptorilor ETB prin Q-788 a determinat o creştere de circa 3 ori mai slabă a constricţiei endotelinice în HAP, sugerând afectarea receptorilor ETB endotelinici.

The in vitro endothelial reactivity of the pulmonary artery was evaluated on 17 patients with pulmonary arterial hypertension (46,29±2,17 mm Hg) the data have being compared with indices of pulmonary artery taken from 12 pts without PAH. The vascular constrictor response to ET-1 action (1,0 nM or 10,0 nM) was significantly increased in PAH, which had become blunted up to control value in the pretreatment of low ET-1 concentration with ETA antagonist, BQ-123. The ETB receptor inhibition with BQ-788 led to a 3-times less enhancement of endothelinic constriction suggesting the endothelial ETB receptor disability.