F. Coceani et al., Deletion of the endothelin-A-receptor suppresses oxygen-induced constriction but not postnatal closure of the ductus arteriosus, J CARDIO PH, 36, 2000, pp. S75-S77
Citations number
6
Categorie Soggetti
Cardiovascular & Respiratory Systems","Cardiovascular & Hematology Research
Experiments were carried out in mutant 129/SvEv mice lacking the endothelin
-A (ETA)-receptor to determine whether endothelin-1 (ET-1), acting as a mes
senger for oxygen constriction, is responsible for closure of the ductus ar
teriosus at birth. The isolated ductus from ETA-/- fetuses, unlike that fro
m ETA +/+ littermates, contracted marginally to oxygen and ET-1 but respond
ed to a thromboxane analog. In vivo, reduction in ductus lumen was equally
pronounced in tracheotomized ETA-/- and ETA +/+ newborns. Conversely, no su
ch vessel narrowing was seen in hyperoxic ETA-/- fetuses, although it occur
red in ETA +/+ littermates. Notwithstanding the uneven behaviour of the duc
tus in vitro and in vivo, no ETA genotype-related difference was noted in t
he morphology of the vessel on both light and electron microscopy. We concl
ude that ET-1 mediates the ductus constriction to oxygen. Without ET-1, how
ever, the vessel still closes postnatally probably as a result of the withd
rawal of the relaxing influence of prostaglandin E-2 (PGE(2)).