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Cardiac Norepinephrine Contents are Influenced by Natriuretic Peptide Receptors
Author(s) -
Trachte George J.
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.20.4.a243-c
Subject(s) - medicine , catecholamine , endocrinology , receptor , pentobarbital , chemistry , norepinephrine , natriuretic peptide , brain natriuretic peptide , heart failure , dopamine
The purpose of the present study was to define the effect of natriuretic peptide receptor (NPR) alterations on tissue catecholamine levels. Transgenic mice lacking functional natriuretic peptide A receptors (NPR‐A) were obtained from Dr. D. Garbers (UT Southwestern) and NPR‐C deficient mice were purchased from Jackson Research Laboratories. Mice were anesthetized with pentobarbital sodium at 25 to 35 days of age and tissues were removed. Catecholamines were extracted and analyzed by high performance liquid chromatography with electrochemical detection. Cardiac norepinephrine contents were suppressed with decreasing functional NPR‐A levels (1.65 ± 0.24 ng/mg in homozygotes and 2.81 ± 0.63 ng/mg in wild type) although these differences did not reach statistical significance (p = 0.15). The hearts from homozygote mice were hypertrophied at this age (8.0 ± 0.4 mg/g vs 6.5 ± 0.2 mg/g in homozygote vs wild‐type hearts) and this difference was significant (p = 0.003). Alterations in NPR‐C levels produced the opposite effect on cardiac catecholamine concentrations. Ablation of functional NPR‐C produced elevated cardiac catecholamine concentrations (6.1 ± 1.5 ng/mg) compared to wild‐type mice (2.97 ± 0.4 ng/mg) and these differences were statistically significant (p = 0.03). There was no influence of NPR‐C alterations on cardiac size. These data indicate that sympathetic innervation is influenced by the natriuretic peptide system with the presence of NPR‐A being associated with greater cardiac catecholamine content and the presence of NPR‐C tending to suppress cardiac catecholamine content. (Study supported by a grant‐in‐aid from the Minnesota Medical Foundation).