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Delta opioid receptors (DORs) and the Autonomic Control of the Heart and Circulation
Author(s) -
Barlow Matthew A.,
Deo Shekhar H,
Gonzalez Leticia,
Yoshishige Darice A,
Caffrey James L
Publication year - 2009
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.23.1_supplement.789.3
Subject(s) - heart rate , endocrinology , medicine , cholinergic , autonomic nervous system , biology , blood pressure
The early stages of diet induced insulin resistance may involve changes in the vasomotor ganglia that regulate muscle blood flow. Delta opioid receptors (DOR) on cholinergic nerves in the heart and sympathetic ganglia actively regulate cholinergic transmission. The DOR‐1 subtype facilitates and the DOR‐2 subtype inhibits vagal transmission. The functional expression of DOR phenotypes depends on gangliosides and lipid rafts that populate local neural membranes. Oxidized lipids may disrupt membrane organization and thus alter normal DOR function. The current study tested the hypothesis that high fat feeding would increase oxidized LDL, disrupt DOR activity and produce a compensatory hyper‐adrenergic state. Body mass, insulin sensitivity, heart rate, heart rate variability, and femoral blood flow were determined in mongrel dogs fed high fat diets for six weeks. DOR receptor mediated changes in vagal control of heart rate and sympathetic control of leg blood flow were determined. High fat feeding increased heart rate and lowered muscle blood flow. Fat feeding reduced the DOR‐2 vagolytic effect in the SA node by half but left companion ganglionic sympatholytic effects unchanged. Facilitory DOR‐1 vagotonic and sympathotonic effects were weak or absent. The data support the suggestion that fat feeding alters the DOR moderation of cholinergic transmission and fosters an unopposed sympathetic overcompensation.