What Is a Dynorphin?

Dynorphin is an opioid peptide with a variety of physiological functions. It was first recognized that it has a significant analgesic function, but it has a strong addiction and drug dependence on the human body. Many functions of the body have obvious regulatory effects, such as the cardiovascular system and the respiratory system.

Dynorphin

Opioid peptides and opioid receptors are widely distributed in the body. For a long time, opioid peptides have been considered to be a central neuropeptide or neurotransmitter, which only plays a role in the central nervous system. In the past 20 years, it has been found that the heart can also synthesize endogenous opioid peptides, and regulate its own function through autocrine or paracrine methods, and its effects are mediated by their respective opioid receptors. The opioid receptors that are closely related to cardiac function are mainly , and subtypes, of which the opioid receptor subtype that dominates the cardiovascular system is the opioid receptor, and dynorphin (Dyn) is the opioid receptor. Endogenous ligand.

Studies have confirmed that myocardial ischemic preconditioning (IPC) can increase the tolerance of the heart to subsequent sustained myocardial ischemia-reperfusion (I / R) injury.This protective effect of IPC on ischemic myocardium is mainly due to lack of Blood triggers the release of endogenous substances. Under normal conditions, the heart can synthesize Dyn and activate the opioid receptor to regulate the cardiovascular system; during myocardial ischemia, endogenous Dyn may be released and participate in the myocardium by activating the opioid receptor The pathological process of ischemia. Therefore, the purpose of this test is to investigate whether endogenous Dyn plays an important role in the myocardial protection of IPC and whether activation of opioid receptors has a direct protective effect on ischemia-reperfusion myocardium.

IPC may promote the release of endogenous opioid peptide Dyn in the body and increase plasma Dyn levels, which can protect the heart by activating kappa opioid receptors. (2) Exogenous opioid U50488H activates opioid receptor, which can significantly reduce the area of myocardial infarction, reduce the leakage of proteases in myocardial cells, and have a direct protective effect on I / R myocardium. (3) Nor-BNI, a specific blocker of opioid receptor, can block the improvement of I / R myocardial contractility by IPC, further proving that opioid receptor mediates the effect of IPC on I / R myocardium. Protective effects.