We know of a monoclonal Ab. vs. angiotensin converting enzyme, but doubt that it's rat specific. For more info. contact QED Advanced Research Technologies in San Diego: phone 619-451-8400, fax 619-451-0105. Good Luck. -- Linscott's Directory of Immunological & Biological Reagents 4877 Grange Rd. Santa Rosa CA 95404 707-544-9555