???? Bradykinin – Definition and Explanations

2023-08-28 21:37:25

Introduction

Bradykinin General CAS No 58-82-2 EINECS No 200-398-8 SMILES InChI Chemical properties Molecular formula C50H73N15O11
Mass (The term mass is used to designate two quantities attached to a…) molar 1,060.2085 ± 0.0514 g mol-1 SI & CNTP units, unless otherwise indicated (An indication (from the Latin indicare: to indicate) is advice or a recommendation, written…) to the contrary.

Bradykinin is a kinin produced under the action of an enzyme (An enzyme is a molecule (protein or RNA in the case of ribozymes) allowing…) released in sweat (Sweat is a liquid secreted by the sweat glands during the event…). It has a vasodilating effect.

It is a peptide hormone (A hormone is a chemical messenger conveyed by the circulatory system which acts…) (nonapeptide) which acts on the smooth muscles, which dilates the blood vessels and which increases the permeability of the capillaries.

Structure

The amino acid sequence of bradykinin is: arg – pro – pro – gly – phe – ser – pro – phe – arg.

Metabolism

In humans, bradykinin is degraded by three kininases: angiotensin converting enzyme (ACE), aminopeptidase P (APP) and carboxypeptidase N (CPN), which cleave positions 7-8, 1 -2, and 8-9, respectively.

Synthesis

The activity of the kinin-kallikrein system leads to the production of bradykinin by proteolytic cleavage of its kininogen precursor, high-weight kininogen (The weight is the force of gravity, of gravitational and inertial origin, exerted by the molecular…) (KHPM), involving an enzyme, kininogenase.

Historical

Bradykinin was discovered by three Brazilian physiologists and pharmacologists working at the Instituto de Biologia de São Paulo, in São Paulo city, directed by Dr. Maurício Rocha e Silva. With colleagues, Wilson Teixeira Beraldo and Gastão Rosenfeld they discovered in 1948 its powerful hypotensive effects in an animal preparations. Bradykinin has been detected in the blood plasma (Blood plasma is the liquid component of blood, in which blood cells are in…) of animals following the addition of venom (Venom is a poisonous substance which is a complex mixture of chemical substances…) of Bothrops (The Bothrops are a genus of snakes, of the family of crotalines, highly venomous, that…) jararaca (snake iron (Iron is a chemical element, symbol Fe and of atomic number 26. It is the Brazilian spear…), which had been brought by Rosenfeld from the Butantan Institute. This discovery was part of an ongoing study on circulatory shock and related proteolytic enzymes to the toxicology (Toxicology is the science of studying) snakebites, initiated by Rocha e Silva as early as 1939. Bradykinin was to prove to be a new principle of autopharmacology, that is to say a substance which is released in the body by metabolic transformation of precursors that are pharmacologically active. According to BJ Hagwood, biographer of Rocha e Silva: “The discovery of bradykinin led to a new understanding of many physiological and pathological phenomena, including induced circulatory shock (The armature is a generally electromagnetic organ used in electrical engineering responsible for …) by venom and toxins. »

Physiological role

Effects

Bradykinin is a potent endothelium-dependent vasodilator, which causes contraction of non-vascular smooth muscle in the circulation systema”, “together…), increases vascular permeability and is also involved in the mechanism of pain (Pain is the sensation felt by an organism whose nervous system detects a…). In some respects, its action is similar to that of histamine; like histamine, it is released from venules rather than arterioles. In the pulmonary circulation (The lungworts are plants of the Boraginaceae family belonging to the genus…), it has a vasoconstrictor effect.

Bradykinin induces an increase in calcium levels (Calcium is a chemical element, with symbol Ca and atomic number 20.) in neocortical astrocytes, so that they release glutamate.

It is believed that bradykinin is the cause of the dry cough (Cough is a sudden, often repetitive, spasmodic contraction of the cavity…) observed in some patients taking ACE-inhibiting drugs. angiotensin (ACE). This intractable cough is a common cause for discontinuation of ACE inhibitor therapy.

Receivers

In mammals, two types of bradykinin receptors are known. The B1 receptor is only expressed following tissue damage and is thought to play a role in chronic pain. The B2 receptor is constitutively active and participates in the vasodilating action of bradykinin.

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