The activity of peptides of the endothelin family in various mammalian smooth muscle preparations
1989; Elsevier BV; Volume: 174; Issue: 1 Linguagem: Inglês
10.1016/0014-2999(89)90869-8
ISSN1879-0712
AutoresCarlo Alberto Maggi, Sandro Giuliani, Riccardo Patacchini, Paolo Rovero, Antonio Giachetti, Alberto Meli,
Tópico(s)Renin-Angiotensin System Studies
ResumoThe activity of natural endothelins such as ET-1, ET-2, ET-3 and of sarafotoxin S6b (SRFTX) as compared to that of the C-terminal hexapeptide ET-(16–21) was investigated in several smooth muscle preparations in the presence of indomethacin, captopril, bestatin and thiorphan. In some tissues (rat thoracic aorta, guinea-pig ileum, human urinary bladder, renal pelvis or renal artery), ET-(16–21) had little if any agonist activity. In order preparations (guinea-pig bronchus, rat vas deferens, rabbit pulmonary artery ET-(16–21) was a full agonist. The amidated form of ET-(16–21) was either inactive or less potent than ET-(16–21). These findings provide evidence that at least two receptors exist for peptides of the ET family; these receptors were termed ETA and ETB. ET-(16–21) is a full agonist at ETB receptors while being inactive or weakly active at ETA receptors. The free acid of tryptophan in position 21 plays a key role in the activity of these peptides at ETB receptors.
Referência(s)