Role of endothelin ETB receptor in the pathogenesis of monocrotaline-induced pulmonary hypertension in rats.

Abstract

We investigated the role of endothelin ETB receptor in the development of monocrotaline-induced pulmonary hypertension, by using the spotting-lethal (sl) rat, which carries a naturally occurring deletion in the endothelin ETB receptor gene. Three weeks after injection of saline or monocrotaline (60 mg/kg, s.c.), hemodynamics, cardiac hypertrophy and endothelin-1 levels in right ventricle were determined. Monocrotaline produced a marked pulmonary hypertension associated with increases in right ventricular pressure and hypertrophy, pulmonary arterial medial thickening and the endothelin-1 levels. The monocrotaline-induced alterations tended to be enhanced in ETB-deficient homozygous rats, compared with cases in wild-type rats. The treatment with selective ETA receptor antagonist ABT-627 [2R-(4-methoxyphenyl)-4S-(1,3-benzodioxol-5-yl)-1-(N,N-di(n-butyl)aminocarbonyl-methyl)-pyrrolidine-3R-carboxylic acid] for 3 weeks (10 mg/kg/day, twice daily) almost completely suppressed the monocrotaline-induced pulmonary hypertension and related organ damage both in ETB-deficient and wild-type animals to the same levels. Thus, we suggest that the antagonism of the ETA receptor is essential for the protection from monocrotaline-induced pulmonary hypertension, irrespective of the presence of the ETB receptors, although a protective role of ETB receptor-mediated action in the pathogenesis of this disease model cannot be ruled out.

• Authors: Masahiro Nishida, Yuka Okada, Kenji Akiyoshi, Keiko Eshiro, Masanori Takoaka, Cheryl E Gariepy, Masashi Yanagisawa, Yasuo Matsumura
• Journal: European journal of pharmacology (Eur J Pharmacol) Vol. 496 Issue 1-3 Pg. 159-65 (Aug 02 2004) ISSN: 0014-2999 [Print] Netherlands
• PMID: 15359489 (Publication Type: Comparative Study, Journal Article, Research Support, Non-U.S. Gov't)

Chemical References

• Endothelin B Receptor Antagonists
• Pyrrolidines
• Receptor, Endothelin B
• Monocrotaline
• Atrasentan

Topics

• Animals
• Animals, Genetically Modified
• Atrasentan
• Endothelin B Receptor Antagonists
• Hypertension, Pulmonary (chemically induced, physiopathology, prevention & control)
• Monocrotaline (toxicity)
• Pulmonary Artery (drug effects, physiology)
• Pyrrolidines (pharmacology, therapeutic use)
• Rats
• Rats, Mutant Strains
• Receptor, Endothelin B (deficiency, physiology)
• Ventricular Function, Right (drug effects, physiology)