In 12 anaesthetized spontaneously breathing pigs divided into two groups of six animals we evaluated the respiratory and haemodynamic responses to endothelin-1 (ET-1) administered by aerosol (200 pmol x kg(-1) in 1 ml of saline solution). In the first group (control group), the responses to ET-1 were evaluated before and after the blocking of endogenous nitric oxide (NO) by NG-nitro-L-arginine methyl ester (L-NAME 5 mg x kg(-1), i.v.). In the second group (indomethacin-pretreated group), the experimental protocol was similar to that of the control group, but the responses were evaluated after the blocking of endogenous prostanoids by indomethacin (3 mg x kg(-1), i.v.). Results show that in the control group ET-1 administered before and after L-NAME did not change compliance (Crs) or resistances (Rrs) of the respiratory system. In indomethacin-pretreated pigs, ET-1 significantly increased Rrs and decreased Crs. This constrictor effect appearing only during the block of arachidonic acid metabolites showed that ET-1 activity can be counterbalanced by a release of dilator prostanoids. In this group after L-NAME pretreatment ET-1 did not alter the mechanical properties of the respiratory system, suggesting an involvement of other bronchodilator mechanisms. In the control group, aerosol administered ET-1 increased mean systemic (MAP) and pulmonary (MPAP) arterial pressures, while when ET-1 was administered after L-NAME pretreatment, MPAP decreased. In the indomethacin-pretreated group, the peptide did not modify MAP, but caused an early decrease in MPAP when administered after L-NAME. Therefore, our results show that ET-1 caused a bronchoconstrictor effect only in indomethacin-pretreated pigs and suggest that the intrinsic constrictor activity of the peptide can be modulated especially by the release of dilator prostanoids.
Prostanoids counterbalance the bronchoconstrictor activity of endothelin-1 in pigs / M.G. Clement, M. Marzani, M. Dimori, M. Albertini. - In: PROSTAGLANDINS LEUKOTRIENES AND ESSENTIAL FATTY ACIDS. - ISSN 0952-3278. - 58:3(1998), pp. 177-183.
Titolo: | Prostanoids counterbalance the bronchoconstrictor activity of endothelin-1 in pigs |
Autori: | CLEMENT, MARIA GIOVANNA (Primo) ALBERTINI, MARIANGELA (Ultimo) |
Settore Scientifico Disciplinare: | Settore VET/02 - Fisiologia Veterinaria |
Data di pubblicazione: | 1998 |
Rivista: | |
Tipologia: | Article (author) |
Digital Object Identifier (DOI): | http://dx.doi.org/10.1016/S0952-3278(98)90111-9 |
Appare nelle tipologie: | 01 - Articolo su periodico |