title: Changes in ambient temperature elicit divergent control of metabolic and cardiovascular actions by leptin.
abstract: Interactions of hypothalamic signaling pathways that control body temperature (BT), blood pressure (BP), and energy balance are poorly understood. We investigated whether the chronic BP and metabolic actions of leptin are differentially modulated by changes in ambient temperature (TA). Mean arterial pressure (MAP), heart rate (HR), BT, motor activity (MA), and oxygen consumption (Vo2) were measured 24 h/d at normal laboratoryTA(23°C), at thermoneutral zone (TNZ, 30°C) for mice or during cold exposure (15°C) in male wild-type mice. After control measurements, leptin (4 μg/kg/min) or saline vehicle was infused for 7 d. At TNZ, leptin reduced food intake (-11.0 ± 0.5 g cumulative deficit) and body weight by 6% but caused no changes in MAP or HR. At 15°C, leptin infusion did not alter food intake but increased MAP and HR (8 ± 1 mmHg and 33 ± 7 bpm), whileVo2increased by ∼10%. Leptin reduced plasma glucose and insulin levels at 15°C but not at 30°C. These results demonstrate that the chronic anorexic effects of leptin are enhanced at TNZ, while its effects on insulin and glucose levels are attenuated and its effects on BP and HR are abolished. Conversely, coldTAcaused resistance to leptin's anorexic effects but amplified its effects to raise BP and reduce insulin and glucose levels. Thus, the brain circuits by which leptin regulates food intake and cardiovascular function are differentially influenced by changes inTA-Do Carmo, J. M., da Silva, A. A., Romero, D. G., Hall, J. E. Changes in ambient temperature elicit divergent control of metabolic and cardiovascular actions by leptin.
authors.affiliation: Department of Physiology and Biophysics, Mississippi Center for Obesity Research, Cardiovascular-Renal Research Center, University of Mississippi Medical Center, Jackson, Mississippi, USA; jdocarmo@umc.edu.
authors.forename: Jussara M
authors.initials: JM
authors.lastname: do Carmo
authors.affiliation: Department of Physiology and Biophysics, Mississippi Center for Obesity Research, Cardiovascular-Renal Research Center, University of Mississippi Medical Center, Jackson, Mississippi, USA.|Centro Universitário Barão de Mauá, Ribeirão Preto, São Paulo, Brazil.
authors.forename: Alexandre A
authors.initials: AA
authors.lastname: da Silva
authors.affiliation: Department of Biochemistry, University of Mississippi Medical Center, Jackson, Mississippi, USA.
authors.forename: Damian G
authors.initials: DG
authors.lastname: Romero
authors.affiliation: Department of Physiology and Biophysics, Mississippi Center for Obesity Research, Cardiovascular-Renal Research Center, University of Mississippi Medical Center, Jackson, Mississippi, USA.
authors.forename: John E
authors.initials: JE
authors.lastname: Hall
mesh_terms: D054369:Agouti-Related Protein / Q000235:genetics / Q000378:metabolism; D000818:Animals; D001786:Blood Glucose; D001794:Blood Pressure / Q000502:physiology; D001835:Body Weight; D004435:Eating; D004734:Energy Metabolism / Q000502:physiology*; D005786:Gene Expression Regulation / Q000502:physiology; D006339:Heart Rate / Q000502:physiology; D007328:Insulin / Q000378:metabolism; D020738:Leptin / Q000008:administration & dosage / Q000378:metabolism* / Q000494:pharmacology; D008297:Male; D051379:Mice; D009419:Nerve Tissue Proteins / Q000235:genetics / Q000378:metabolism; D009478:Neuropeptide Y / Q000235:genetics / Q000378:metabolism; D011333:Pro-Opiomelanocortin / Q000235:genetics / Q000378:metabolism; D054411:Receptors, Leptin; D013696:Temperature; D000098882:Cocaine- and Amphetamine-Regulated Transcript Protein
chemical_list: D054369:Agouti-Related Protein; D001786:Blood Glucose; D007328:Insulin; D020738:Leptin; D009419:Nerve Tissue Proteins; D009478:Neuropeptide Y; D054411:Receptors, Leptin; D000098882:Cocaine- and Amphetamine-Regulated Transcript Protein; D011333:Pro-Opiomelanocortin
keywords: blood pressure; energy expenditure; food intake; heart rate