Kinins: A generic term used to describe a group of polypeptides with related chemical structures and pharmacological properties that are widely distributed in nature. These peptides are AUTACOIDS that act locally to produce pain, vasodilatation, increased vascular permeability, and the synthesis of prostaglandins. Thus, they comprise a subset of the large number of mediators that contribute to the inflammatory response. (From Goodman and Gilman's The Pharmacologic Basis of Therapeutics, 8th ed, p588)Receptor, Bradykinin B1: A subtype of BRADYKININ RECEPTOR that is induced in response to INFLAMMATION. It may play a role in chronic inflammation and has a high specificity for KININS lacking the C-terminal ARGININE such as des-Arg(10)-kallidin and des-Arg(9)-bradykinin. The receptor is coupled to G-PROTEIN, GQ-G11 ALPHA FAMILY and G-PROTEIN, GI-GO ALPHA FAMILY signaling proteins.Receptor, Bradykinin B2: A constitutively expressed subtype of bradykinin receptor that may play a role in the acute phase of the inflammatory and pain response. It has high specificity for intact forms of BRADYKININ and KALLIDIN. The receptor is coupled to G-PROTEIN, GQ-G11 ALPHA FAMILY and G-PROTEIN, GI-GO ALPHA FAMILY signaling proteins.Bradykinin: A nonapeptide messenger that is enzymatically produced from KALLIDIN in the blood where it is a potent but short-lived agent of arteriolar dilation and increased capillary permeability. Bradykinin is also released from MAST CELLS during asthma attacks, from gut walls as a gastrointestinal vasodilator, from damaged tissues as a pain signal, and may be a neurotransmitter.Kallikrein-Kinin System: A system of metabolic interactions by products produced in the distal nephron of the KIDNEY. These products include KALLIKREIN; KININS; KININASE I; KININASE II; and ENKEPHALINASE. This system participates in the control of renal functions. It interacts with the RENIN-ANGIOTENSIN-ALDOSTERONE SYSTEM to regulate BLOOD PRESSURE, generation of PROSTAGLANDINS, release of VASOPRESSINS, and WATER-ELECTROLYTE BALANCE.Kininogens: Endogenous peptides present in most body fluids. Certain enzymes convert them to active KININS which are involved in inflammation, blood clotting, complement reactions, etc. Kininogens belong to the cystatin superfamily. They are cysteine proteinase inhibitors. HIGH-MOLECULAR-WEIGHT KININOGEN; (HMWK); is split by plasma kallikrein to produce BRADYKININ. LOW-MOLECULAR-WEIGHT KININOGEN; (LMWK); is split by tissue kallikrein to produce KALLIDIN.Kallikreins: Proteolytic enzymes from the serine endopeptidase family found in normal blood and urine. Specifically, Kallikreins are potent vasodilators and hypotensives and increase vascular permeability and affect smooth muscle. They act as infertility agents in men. Three forms are recognized, PLASMA KALLIKREIN (EC 220.127.116.11), TISSUE KALLIKREIN (EC 18.104.22.168), and PROSTATE-SPECIFIC ANTIGEN (EC 22.214.171.124).Tissue Kallikreins: A family of trypsin-like SERINE ENDOPEPTIDASES that are expressed in a variety of cell types including human prostate epithelial cells. They are formed from tissue prokallikrein by action with TRYPSIN. They are highly similar to PROSTATE-SPECIFIC ANTIGEN.Lysine Carboxypeptidase: A metallocarboxypeptidase that removes C-terminal basic amino acid from peptides and proteins, with preference shown for lysine over arginine. It is a plasma zinc enzyme that inactivates bradykinin and anaphylatoxins.Prekallikrein: A plasma protein which is the precursor of kallikrein. Plasma that is deficient in prekallikrein has been found to be abnormal in thromboplastin formation, kinin generation, evolution of a permeability globulin, and plasmin formation. The absence of prekallikrein in plasma leads to Fletcher factor deficiency, a congenital disease.Aprotinin: A single-chain polypeptide derived from bovine tissues consisting of 58 amino-acid residues. It is an inhibitor of proteolytic enzymes including CHYMOTRYPSIN; KALLIKREIN; PLASMIN; and TRYPSIN. It is used in the treatment of HEMORRHAGE associated with raised plasma concentrations of plasmin. It is also used to reduce blood loss and transfusion requirements in patients at high risk of major blood loss during and following open heart surgery with EXTRACORPOREAL CIRCULATION. (Reynolds JEF(Ed): Martindale: The Extra Pharmacopoeia (electronic version). Micromedex, Inc, Englewood, CO, 1995)Angiotensin-Converting Enzyme Inhibitors: A class of drugs whose main indications are the treatment of hypertension and heart failure. They exert their hemodynamic effect mainly by inhibiting the renin-angiotensin system. They also modulate sympathetic nervous system activity and increase prostaglandin synthesis. They cause mainly vasodilation and mild natriuresis without affecting heart rate and contractility.Captopril: A potent and specific inhibitor of PEPTIDYL-DIPEPTIDASE A. It blocks the conversion of ANGIOTENSIN I to ANGIOTENSIN II, a vasoconstrictor and important regulator of arterial blood pressure. Captopril acts to suppress the RENIN-ANGIOTENSIN SYSTEM and inhibits pressure responses to exogenous angiotensin.Kininogen, Low-Molecular-Weight: A protein, molecular weight 50 kD, located in various normal tissues. Upon cleavage by KALLIKREINS, it forms KALLIDIN. Kallidin, in turn, is converted into BRADYKININ. (From Stedman, 25th ed)Edema: Abnormal fluid accumulation in TISSUES or body cavities. Most cases of edema are present under the SKIN in SUBCUTANEOUS TISSUE.Plasma Kallikrein: A peptidohydrolytic enzyme that is formed from PREKALLIKREIN by FACTOR XIIA. It activates FACTOR XII; FACTOR VII; and PLASMINOGEN. It is selective for both ARGININE and to a lesser extent LYSINE bonds. EC 126.96.36.199.