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Norepinephrine transporter protein does not correlate with sympathetic innervation density in the heart
Author(s) -
Wright Anna A,
Wehrwein EA,
Fink GD,
Kreulen DL
Publication year - 2006
Publication title -
the faseb journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.709
H-Index - 277
eISSN - 1530-6860
pISSN - 0892-6638
DOI - 10.1096/fasebj.20.5.a1201
Subject(s) - norepinephrine transporter , medicine , norepinephrine , endocrinology , denervation , atrium (architecture) , chemistry , biology , dopamine , atrial fibrillation
Denervation studies indicate that norepinephrine transporter (NET) protein is located in sympathetic nerve terminals. The purpose of this study was to assess whether NET protein correlates with the sympathetic innervation density of the heart. We hypothesized that the greatest concentration of NET protein would be in the right atrium of the heart since NE content and nerve terminal density are highest in the atria compared to the ventricles. Adult, male Sprague‐Dawley (4 weeks) rats were used in the study (n=6). Hearts were removed and separated by chambers. Frozen tissue was processed and isolated heart chambers were analyzed with western blotting for NET. Three molecular weight variants of NET protein were detected (~80 kD, 54 kD, and 46 kD) in the myocardium with the following pattern: 80 kD>54 kD>46 kD (p<0.05). This relationship among the variants was the same in all heart chambers. When normalized to the total protein content of each of the chambers, all three variants were found in greater amounts in the ventricles compared to the atria. Therefore, the results did not support the hypothesis that NET protein would correlate with innervation density of the heart; rather NET appears to be equally distributed throughout the myocardium and possibly has an alternative source such as sensory nerve fibers, or intrinsic cardiac adrenergic cells. P01HL70687.