التفاصيل البيبلوغرافية
| العنوان: |
Enhanced norepinephrine concentrations in interstitium of skeletal muscle after myocardial infarction. |
| المؤلفون: |
Jihong Xing, Koba, Satoshi, Kehoe, Valerie, King, Nicholas, Sinoway, Lawrence I., Jianhua Li |
| المصدر: |
FASEB Journal; Apr2007, Vol. 21 Issue 6, pA1270-A1270, 1/4p |
| مصطلحات موضوعية: |
NORADRENALINE, MYOCARDIAL infarction, SYMPATHETIC nervous system, VASOCONSTRICTION, HEART failure, LABORATORY rats |
| مستخلص: |
Enhanced peripheral sympathetic nervous activity and the resultant increased neurovascular levels of norepinephrine (NE) evoke vasoconstriction and serve to maintain blood pressure and perfusion to vital organs. Sympathetic nervous activity increases in patients with heart failure (HF). Thus, sympathetic constrictor activity is exaggerated in HF. Previous work show that interstitial NE concentrations ([NE]i) is increased from the sympathetic nerves in active muscles. In this study, we examined [NE]i in hindlimb muscles of healthy control rats and rats with HF due to chronic myocardial infarction (Ml). We tested the hypothesis that sympathetic nerve activation would increase NEi to a greater extent in HF than in controls. NEi samples were collected from microdialysis probes inserted into the hindlimb muscle in decerebrate rats. The dialysate concentration of NE was determined by the HPLC method. [NE]i was increased 17%, 20% and 25% by electrical stimulation of the lumbar sympathetic nerves of eight healthy control rats with 1, 2 and 4 Hz frequency, respectively. Increases in [NE]i were significantly greater (33%, 47% and 66% by 1, 2 and 4 Hz, P<0.05 vs. controls) in ten severe MI rats. In addition, a regression analysis showed an inverse linear relationship between NE response induced by sympathetic stimulation and fractional shortening, an indication of left ventricle function. Our results show that muscle NEi is enhanced after MI due to altered sympathetic nervous activity. This study suggests that the regulation of NE at the muscle neurovascular junction is altered in HF. [ABSTRACT FROM AUTHOR] |
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| قاعدة البيانات: |
Complementary Index |