The kallikrein-kinin system has been implicated as having a role in blood pressure regulation, in renal function, and in the inflammatory response. The application focuses on the bradykinin (BK) receptor component of this system. The purpose of this proposal is to prepare monoclonal antibodies that react with BK receptors and to use these antibodies and/or their F(ab) or F(ab)2 fragments to: 1. determine the immunological similarity of BK receptors from bovine uterine myometrium and those from rat uterus, guinea pig ileum, dog carotid artery and rabbit jugular and mesenteric veins and aorta. These experiments will be done in vitro by testing the antibodies for their abilities to act as agonists or antagonists in these isolated biological preparations. Results of these experiments could result in a further classification of BK receptors should antibodies display agonist activities in some preparation but antagonist activities in others. These experiments will be done in collaborations with Dr. Oscar Carretero, Detroit, MI, Dr. Domenico Regoli, Sherbrooke, Canada and Dr. John M. Stewart, Denver, CO. 2. determine if they have a longer duration of action in vivo than do BK peptide agonists or antagonists. Should the antibodies have longer durations of actions, chronic experiments on the physiological and pathological roles of kinins will be more feasible than with BK analogs alone. These experiments will be done in rats and effects on blood pressure examined. 3. determine if, when labeled with 125I, they are better suited for direct binding studies for BK receptors in tissues rich in kininases than are 125I- labeled BK analogs. One of the problems associated with the use of radioactive kinins for BK receptor studies is their binding to non-receptor sites e.g. kininases. Presumably, monoclonal antibodies will be more specific for BK receptors and therefore receptor studies employing them will be less likely to be complicated by binding to non-receptor sites. These experiments will be done on slices and subcellular fractions from bovine uterine myometrium and porcine kidney. 4. make an immunoaffinity resin that will be used in the purification of BK receptors. The ability to isolate relatively large amounts of purified BK receptors will make it possible to physically and chemically characterize this kinin binding entity. The results of the experiments to be performed in this proposal will further our understanding of BK receptors in vascular and non-vascular tissues and will provide the first information about the kinin binding properties of purified BK receptors.