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Aging is associated with resistance to the cardiovascular actions of leptin for baroreflex modulation
Author(s) -
Arnold Amy Christine,
Diz Debra I
Publication year - 2010
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.24.1_supplement.624.8
Subject(s) - leptin , baroreflex , medicine , endocrinology , microinjection , blood pressure , heart rate , obesity
Aging is associated with resistance to the metabolic actions of leptin. However, age‐related leptin sensitivity for cardiovascular actions is unknown. Therefore, we determined the effect of leptin microinjection (500 fmol/60 nL) in the solitary tract nucleus (NTS) on baroreflex sensitivity (BRS) for control of heart rate (HR) in older (16 to 20 months) urethane/chloralose anesthetized Sprague‐Dawley (SD) rats with elevated circulating leptin levels. In contrast to the 53% reduction in BRS in younger SD rats, NTS injection of leptin produced no significant change in BRS to increases in pressure (n = 4; 0.93 ± 0.20 baseline vs 0.75 ± 0.23 msec/mm Hg after leptin) in the older SD rats. There were no significant effects of leptin on BRS to decreases in pressure, resting arterial pressure or HR in younger or older SD rats. These data suggest that aging is associated with resistance to the baroreflex actions of exogenous leptin. Whether the elevated circulating leptin levels accompanying age‐related metabolic dysfunction contribute to baroreflex suppression in elderly populations remains unclear, but may provide insight into mechanisms underlying age‐related baroreflex dysfunction. Support: HL‐51952