Norepinephrine release is reduced in cardiac tissue of Type 2 diabetic patients.
OBJECTIVE
The aim of this study was to assess whether cardiac catecholamine release is affected in patients with Type 2 diabetes mellitus.


METHODS
A trial tissue was obtained from 19 diabetic (Type 2) and 43 non-diabetic patients undergoing coronary surgery. Endogenous norepinephrine release was examined under baseline conditions as well as during electrical field stimulation (effective voltage 5 V, stimulation frequency 4 Hz, pulse width 2 msec) by high performance liquid chromatography and electrochemical detection. Cardiac function and arterial blood pressure was assessed from coronary angiography.


RESULTS
In atrial tissue from diabetic patients, stimulation-induced norepinephrine release was reduced by 25% compared with non-diabetic patients, while baseline norepinephrine release did not differ between both groups. Preoperative plasma glucose and haemoglobin A(1C) concentrations were increased in patients with diabetes, however, no relation was found to catecholamine release. Diabetic and non-diabetic patients did not differ regarding left ventricular ejection fraction and arterial blood pressure.


CONCLUSIONS
Cardiac norepinephrine release is suppressed in patients with Type 2 diabetes which could contribute to sympathetic neuropathy. The difference of norepinephrine release in diabetic and non-diabetic patients was independent of cardiac function and arterial blood pressure.
Medizinische Klinik II, Universitätsklinikum Lübeck, Ratzeburger Allee 160, 23538, Lübeck, Germany. chbrg@compuserve.de
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Burgdorf
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Richardt
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Kurz
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Adler
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Nötzold
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Kraatz
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Sievers
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Richardt
D000368:Aged; D020517:Atrial Appendage / Q000378:metabolism*; D003924:Diabetes Mellitus, Type 2 / Q000378:metabolism* / Q000503:physiopathology*; D005089:Exocytosis / Q000502:physiology; D005260:Female; D006801:Humans; D008297:Male; D009206:Myocardium / Q000378:metabolism*; D009638:Norepinephrine / Q000378:metabolism* / Q000493:pharmacokinetics*
D009638:Norepinephrine