Real-time In Situ Detection Of Norepinephrine Secretion In Live Mouse Heart

The physiological activities of the heart are mainly regulated by the sympathetic nervous system.The systolic and diastolic functions of the heart are regulated by sympathetic nerve endings secreting NE acting on adrenal receptors on cardiomyocytes.The occurrence of some common heart disease,such as heart failure,arrhythmia,hypertension and so on,are accompanied by abnormal NE secretion.Therefore,the detection of NE secretion in the heart is important for the prevention and treatment of heart disease.However,some methods such as radioisotope dilution method,electrophysiological method,electrochemical method and methods to detect the total amount of NE in the homogenate of heart tissues are not exact in spatial and temporal,and cannot reflect the changes of NE secretion in the living heart.Using the experimental principle of cardiac Slice Electro Chemistry(c SEC)and based on cardiac Slice Electro Chemistry(c SEC),we established a real-time in-situ method for the detection of NE secretion changes in the hearts of living mice,which is called cardiac Physiological Electro Chemistry(cPEC).We used cPEC method to record the oxidative current signal of the hearts of living mice successfully,and used the following experimental methods to verified that cPEC signal is the oxidative signal of the norepinephrine secreted by sympathetic nerve endings of the heart :(1)the cPEC signal is voltage dependent;(2)the presynaptic α2-AR agonist NE and clonidine can reduce the cPEC signal significantly;(3)the blocking agent reserpine of monoamine transporter VMAT can reduce the cPEC signal significantly;(4)microdialysis-high performance liquid chromatography demonstrated that the cPEC signal was mainly from norepinephrine released from sympathetic nerve endings of the heart.The above results fully demonstrate that the cPEC signal mainly comes from norepinephrine released from sympathetic nerve endings of the heart.The cPEC technology is the first method to detection norepinephrine secretion real-time in-situ in the sympathetic nerve terminals of the heart in the world,providing a new means for the prevention and treatment of heart failure and other heart diseases...