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Alternative sources of cardiac norepinephrine (NE) transporter (NET)
Author(s) -
Wehrwein Erica A,
Bloch K,
Spitsbergen J M,
Yoshimoto M,
Osborn J W,
Kreulen D L
Publication year - 2008
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.22.1_supplement.1230.10
Subject(s) - norepinephrine transporter , medicine , norepinephrine , endocrinology , sympathetic nervous system , cholinergic , biology , chemistry , dopamine , blood pressure
Cardiac norepinephrine (NE) is cleared from the neuroeffector junction by NE transporter (NET) and reuptake is impaired in many diseases. Cardiac NET is in sympathetic neurons and intrinsic cardiac adrenergic cells, and NE uptake is reduced by sympathetic denervation. However, we report substantial NET protein in the sympathetically denervated heart and thus examined alternative localization of NET in other nervous structures within the heart. We hypothesized that NET was in cardiac sensory and/or cholinergic neurons. Normal adult Sprague‐Dawley rats were used (n=7). NET mRNA and protein are found in sympathetic stellate ganglia and NET immunoreactivity (IR) is colocalized with tyrosine hyrdoxylase (TH)‐positive fibers in the heart. However, there are NET positive‐TH negative fibers. NET mRNA and protein are found in dorsal root ganglia; however, NET IR was not colocalized with calcitonin gene related peptide in sensory nerve fibers in the heart. NET mRNA is present and NET IR is colocalized with choline acetyl transferase‐positive intrinsic ganglia and fibers in the left atria. Thus, NET is found in sympathetic, sensory, and intrinsic cardiac ganglia, and in sympathetic and cholinergic fibers. In conclusion, there are alternative sources of cardiac NET protein aside from sympathetic nerve fibers that should be considered in the study of NET function. P01HL70687, AHA predoctoral fellowship (Wehrwein)