Functional role, cellular source, and tissue distribution of rat elastase-2, an angiotensin II-forming enzyme

• Published in: American journal of physiology. Heart and circulatory physiology 2003-08, Vol.285 (2), p.H775-H783
• Main Authors: Santos, Carlos F, Caprio, Marcos Antonio V, Oliveira, Eduardo B, Salgado, Maria Cristina O, Schippers, Daniela N, Munzenmaier, Diane H, Greene, Andrew S
• Format: Article
• Language: English
• Subjects: Angiotensin II - biosynthesis; Angiotensin-Converting Enzyme Inhibitors - pharmacology; Animals; Captopril - pharmacology; Culture Media, Conditioned - pharmacology; Endothelium, Vascular - enzymology; Enzyme Activation - drug effects; Gene Expression Regulation, Enzymologic; In Vitro Techniques; Male; Mesenteric Arteries - enzymology; Oligopeptides - pharmacology; Perfusion - standards; Rats; Rats, Sprague-Dawley; Rats, Wistar; Reproducibility of Results; RNA, Messenger - analysis; Serine Endopeptidases - genetics; Serine Endopeptidases - isolation & purification; Serine Endopeptidases - metabolism; Serine Proteinase Inhibitors - pharmacology; Viscera - enzymology
• ISSN: 0363-6135; 1522-1539
• DOI: 10.1152/ajpheart.00818.2002

Departments of 1 Pharmacology and 2 Biochemistry and Immunology, University of São Paulo School of Medicine, Ribeirão Preto 14049-900, Brazil; and 3 Department of Physiology and 4 Biotechnology and Bioengineering Center, Medical College of Wisconsin, Milwaukee, Wisconsin 53226 Submitted 19 September 2002 ; accepted in final form 15 April 2003 We recently described a chymostatin-sensitive elastase-2 as the major angiotensin (ANG) II-forming enzyme in the perfusate of the rat mesenteric arterial bed (MAB) with the same cDNA sequence as rat pancreatic elastase-2. The role of this enzyme in generating ANG II was examined in the rat isolated and perfused MAB. The vasoconstrictor effect elicited by ANG I and the renin substrate tetradecapeptide was only partially inhibited by captopril but abolished by the combination of captopril and chymostatin or N -acetyl-Ala-Ala-Pro-Leu-chloromethylketone (Ac-AAPL-CK; inhibitor originally developed for human elastase-2). The effect induced by [Pro 11 , D -Ala 12 ]-ANG I, an ANG I-converting enzyme (ACE)-resistant biologically inactive precursor of ANG II, was blocked by chymostatin or Ac-AAPL-CK. It was also demonstrated that cultured rat mesenteric endothelial cells synthesize elastase-2 and that mRNA for this enzyme can be detected in different rat tissues such as the pancreas, MAB, lung, heart, kidney, liver, and spleen. In conclusion, the demonstration of a functional alternative pathway to ACE for ANG II generation in the rat MAB and the fact that cultured MAB endothelial cells are capable of producing and secreting elastase-2 represent strong evidence of a physiological role for this enzyme in the rat vasculature. endothelium; chymostatin Address for reprint requests and other correspondence: A. S. Greene, Dept. of Physiology, Medical College of Wisconsin, Rm. 549, 8701 Watertown Plank Rd., Milwaukee, WI 53226 (E-mail: agreene{at}mcw.edu ).