title: Central angiotensin AT1 receptors are involved in metabolic adjustments in response to graded exercise in rats.
abstract: To investigate the influence of central angiotensin AT1-receptors blockade on metabolic adjustments during graded exercise, Losartan (Los) was intracerebroventricularly injected in rats before running until fatigue. Oxygen consumption (VO2) was measured (n=6) and blood samples collected (n=7) to determine variations of glucose, lactate and free fatty acids (FFA). Los-rats exhibited a hyperglycemic response, already observed at 20% of maximal work, followed by a higher lactate levels and FFA mobilization from adipose tissue. Despite the reduced total time to fatigue and the higher VO2 associated with reduced mechanical efficiency, exercise led to the attainment of similar levels of effort in both groups. In summary, central AT1-receptor blockade during graded exercise induces hyperglycemia and higher FFA mobilization from adipose tissue at low exercise intensities in rats running at the same absolute exercise intensity. These data suggest that the central angiotensinergic system is involved in metabolic adjustments during exercise since central blockade of AT1-receptors shifts energy balance during graded exercise, similarly to situations of higher and premature sympathetic activation.
authors: Department of Physiology and Biophysics, Institute of Biological Sciences, Federal University of Minas Gerais, 31270-901 Belo Horizonte, Minas Gerais, Brazil.
authors: Laura H R
authors: LH
authors: Leite
authors: Ana Cristina R
authors: AC
authors: Lacerda
authors: Cláudio H
authors: CH
authors: Balthazar
authors: Umeko
authors: U
authors: Marubayashi
authors: Cândido C
authors: CC
authors: Coimbra
mesh_terms: D047228:Angiotensin II Type 1 Receptor Blockers / Q000378:metabolism; D000818:Animals; D001786:Blood Glucose / Q000378:metabolism; D004734:Energy Metabolism; D005230:Fatty Acids, Nonesterified / Q000097:blood; D019344:Lactic Acid / Q000097:blood; D019808:Losartan / Q000378:metabolism; D008297:Male; D010101:Oxygen Consumption / Q000502:physiology*; D010805:Physical Conditioning, Animal / Q000502:physiology*; D011897:Random Allocation; D051381:Rats; D017208:Rats, Wistar; D044140:Receptor, Angiotensin, Type 1 / Q000378:metabolism*; D012420:Running / Q000502:physiology
chemical_list: D047228:Angiotensin II Type 1 Receptor Blockers; D001786:Blood Glucose; D005230:Fatty Acids, Nonesterified; D044140:Receptor, Angiotensin, Type 1; D019344:Lactic Acid; D019808:Losartan