Premium
Peripheral leptin decreases arterial pressure and increases heart rate while maintaining fed‐state metabolic rate during negative energy balance
Author(s) -
Knight W David,
Seth Rohit,
Overton J Michael
Publication year - 2007
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.21.5.a458-b
Subject(s) - leptin , medicine , endocrinology , heart rate , blood pressure , bradycardia , basal metabolic rate , saline , peripheral , anorectic , energy expenditure , chemistry , body weight , obesity
Leptin infusions reducing food intake by 30–50% increase blood pressure (MAP) without increasing heart rate (HR). To test the effects of low‐dose, peripheral leptin on cardiovascular and metabolic function, male FBNF1 rats were instrumented for telemetry, housed in metabolic chambers, and given leptin (LEP: 25ug/kg/hr) or vehicle (SAL: 10ul/hr) via a mini‐osmotic pump for seven days. LEP raised serum levels ( SAL :5.4±0.8 LEP :13.1±2.7 ng/ml) and reduced food intake by 10% compared to controls ( SAL :403±15 LEP :360±13 kcals); a separate group given saline was pair‐fed (PF) to LEP. Interestingly, LEP infusion decreased light phase MAP ( SAL :94±1 LEP :85±1 PF :92±1 mmHg) and prevented anorectic bradycardia ( SAL :319±6 LEP :326±4 PF :285±5 bpm). LEP also prevented reductions in energy expenditure (EE) ( SAL :60±2 LEP :62±1 PF :53±1 kcals) and decreased respiratory quotient ( SAL :0.88±0.01 LEP :0.85±0.01 PF :0.87±0.01). This experiment was repeated at 29°C to study leptin action during low basal sympathetic activity. Interestingly, LEP again decreased MAP ( SAL :80±1 LEP :74±2 PF :78±2 mmHg) and maintained EE ( SAL :39±1 LEP :40±2 PF :34±1 kcals). LEP also unexpectedly increased HR above controls ( SAL :261±3 LEP :278±5 PF :228±3 bpm). These data indicate peripheral leptin has divergent effects on ingestive, cardiovascular, and metabolic function that are influenced by ambient temperature. Supported by NIH HL‐56732.