Angiotensin II-induced inotropism requires an endocardial endothelium-nitric oxide mechanism in the in-vitro heart of Anguilla anguilla
SUMMARY Using an isolated working heart preparation we show that angiotensin II(ANG II), at concentrations of 10-10–10-7 mol l-1, elicits negative chronotropism and inotropism in the freshwater eel Anguilla anguilla. The negative inotropism was insensitive to losartan and CGP42112 (AT1 and AT2 ANG...
Published in: | Journal of Experimental Biology |
---|---|
Main Authors: | , , |
Format: | Article in Journal/Newspaper |
Language: | English |
Published: |
2003
|
Subjects: | |
Online Access: | https://www.openaccessrepository.it/record/154814 https://doi.org/10.1242/jeb.00468 |
id |
ftopenaccessrep:oai:zenodo.org:154814 |
---|---|
record_format |
openpolar |
spelling |
ftopenaccessrep:oai:zenodo.org:154814 2024-05-12T07:52:57+00:00 Angiotensin II-induced inotropism requires an endocardial endothelium-nitric oxide mechanism in the in-vitro heart of Anguilla anguilla Imbrogno, Sandra Cerra, Maria Carmela Tota, Bruno 2003-06-21 https://www.openaccessrepository.it/record/154814 https://doi.org/10.1242/jeb.00468 eng eng url:https://www.openaccessrepository.it/communities/itmirror https://www.openaccessrepository.it/record/154814 doi:10.1242/jeb.00468 info:eu-repo/semantics/openAccess Insect Science Molecular Biology Animal Science and Zoology Aquatic Science Physiology Ecology Evolution Behavior and Systematics info:eu-repo/semantics/article publication-article 2003 ftopenaccessrep https://doi.org/10.1242/jeb.00468 2024-04-17T14:48:21Z SUMMARY Using an isolated working heart preparation we show that angiotensin II(ANG II), at concentrations of 10-10–10-7 mol l-1, elicits negative chronotropism and inotropism in the freshwater eel Anguilla anguilla. The negative inotropism was insensitive to losartan and CGP42112 (AT1 and AT2 ANG II receptor antagonists, respectively), and was abrogated by the AT1receptor antagonist CV11974, the G protein blocker pertussis toxin (PTx) and the muscarinic antagonist atropine. In contrast, it was not affected by the adrenoceptor antagonists propanolol, sotalol and phentolamine. Using donors(l-arginine) and inhibitors[NG-monomethyl-L-arginine (l-NMMA), l-N5(1-iminoethyl)ornithine (L-NIO)] of nitric oxide synthase (NOS), and haemoglobin as NO scavenger, we demonstrate that NO signalling is involved in ANG II-mediated inotropism. Pretreatment with Triton X-100, a detergent that damages the endocardial endothelium (EE),or with 1H-(1,2,4)oxadiazolo-(4,3-a)quinoxalin-1-one (ODQ), a specific inhibitor of soluble guanylate cyclase, or with the cGMP-activated protein kinase (PKG) inhibitor KT5328, abolished ANG II-mediated inotropism. Thus, ANG II-mediated inotropism occurs via an EE-NO-cGMP-PKG mechanism. ANG II did not affect the mechanical performance influenced by preload changes (i.e. the Frank–Starling response), which in the eel heart is modulated by NO. This EE-paracrine-mediated cardio-suppressive action of endoluminal ANG II suggests that the hormone plays an important intracardiac role in the fish heart. Article in Journal/Newspaper Anguilla anguilla Istituto Nazionale di Fisica Nucleare (INFN): Open Access Repository Triton ENVELOPE(-55.615,-55.615,49.517,49.517) Journal of Experimental Biology 206 15 2675 2684 |
institution |
Open Polar |
collection |
Istituto Nazionale di Fisica Nucleare (INFN): Open Access Repository |
op_collection_id |
ftopenaccessrep |
language |
English |
topic |
Insect Science Molecular Biology Animal Science and Zoology Aquatic Science Physiology Ecology Evolution Behavior and Systematics |
spellingShingle |
Insect Science Molecular Biology Animal Science and Zoology Aquatic Science Physiology Ecology Evolution Behavior and Systematics Imbrogno, Sandra Cerra, Maria Carmela Tota, Bruno Angiotensin II-induced inotropism requires an endocardial endothelium-nitric oxide mechanism in the in-vitro heart of Anguilla anguilla |
topic_facet |
Insect Science Molecular Biology Animal Science and Zoology Aquatic Science Physiology Ecology Evolution Behavior and Systematics |
description |
SUMMARY Using an isolated working heart preparation we show that angiotensin II(ANG II), at concentrations of 10-10–10-7 mol l-1, elicits negative chronotropism and inotropism in the freshwater eel Anguilla anguilla. The negative inotropism was insensitive to losartan and CGP42112 (AT1 and AT2 ANG II receptor antagonists, respectively), and was abrogated by the AT1receptor antagonist CV11974, the G protein blocker pertussis toxin (PTx) and the muscarinic antagonist atropine. In contrast, it was not affected by the adrenoceptor antagonists propanolol, sotalol and phentolamine. Using donors(l-arginine) and inhibitors[NG-monomethyl-L-arginine (l-NMMA), l-N5(1-iminoethyl)ornithine (L-NIO)] of nitric oxide synthase (NOS), and haemoglobin as NO scavenger, we demonstrate that NO signalling is involved in ANG II-mediated inotropism. Pretreatment with Triton X-100, a detergent that damages the endocardial endothelium (EE),or with 1H-(1,2,4)oxadiazolo-(4,3-a)quinoxalin-1-one (ODQ), a specific inhibitor of soluble guanylate cyclase, or with the cGMP-activated protein kinase (PKG) inhibitor KT5328, abolished ANG II-mediated inotropism. Thus, ANG II-mediated inotropism occurs via an EE-NO-cGMP-PKG mechanism. ANG II did not affect the mechanical performance influenced by preload changes (i.e. the Frank–Starling response), which in the eel heart is modulated by NO. This EE-paracrine-mediated cardio-suppressive action of endoluminal ANG II suggests that the hormone plays an important intracardiac role in the fish heart. |
format |
Article in Journal/Newspaper |
author |
Imbrogno, Sandra Cerra, Maria Carmela Tota, Bruno |
author_facet |
Imbrogno, Sandra Cerra, Maria Carmela Tota, Bruno |
author_sort |
Imbrogno, Sandra |
title |
Angiotensin II-induced inotropism requires an endocardial endothelium-nitric oxide mechanism in the in-vitro heart of Anguilla anguilla |
title_short |
Angiotensin II-induced inotropism requires an endocardial endothelium-nitric oxide mechanism in the in-vitro heart of Anguilla anguilla |
title_full |
Angiotensin II-induced inotropism requires an endocardial endothelium-nitric oxide mechanism in the in-vitro heart of Anguilla anguilla |
title_fullStr |
Angiotensin II-induced inotropism requires an endocardial endothelium-nitric oxide mechanism in the in-vitro heart of Anguilla anguilla |
title_full_unstemmed |
Angiotensin II-induced inotropism requires an endocardial endothelium-nitric oxide mechanism in the in-vitro heart of Anguilla anguilla |
title_sort |
angiotensin ii-induced inotropism requires an endocardial endothelium-nitric oxide mechanism in the in-vitro heart of anguilla anguilla |
publishDate |
2003 |
url |
https://www.openaccessrepository.it/record/154814 https://doi.org/10.1242/jeb.00468 |
long_lat |
ENVELOPE(-55.615,-55.615,49.517,49.517) |
geographic |
Triton |
geographic_facet |
Triton |
genre |
Anguilla anguilla |
genre_facet |
Anguilla anguilla |
op_relation |
url:https://www.openaccessrepository.it/communities/itmirror https://www.openaccessrepository.it/record/154814 doi:10.1242/jeb.00468 |
op_rights |
info:eu-repo/semantics/openAccess |
op_doi |
https://doi.org/10.1242/jeb.00468 |
container_title |
Journal of Experimental Biology |
container_volume |
206 |
container_issue |
15 |
container_start_page |
2675 |
op_container_end_page |
2684 |
_version_ |
1798839198871977984 |