Central angiotensin AT sub(1) receptors are involved in metabolic adjustments in response to graded exercise in rats

• Published in: Peptides (New York, N.Y. : 1980) N.Y. : 1980), 2009-10, Vol.30 (10), p.1931-1935
• Main Authors: Leite, Laura HR, Lacerda, Ana Cristina R, Balthazar, Claudio H, Marubayashi, Umeko, Coimbra, Candido C
• Format: Article
• Language: English
• ISSN: 0196-9781
• DOI: 10.1016/j.peptides.2009.07.018

To investigate the influence of central angiotensin AT sub(1)-receptors blockade on metabolic adjustments during graded exercise, Losartan (Los) was intracerebroventricularly injected in rats before running until fatigue. Oxygen consumption (VO sub(2)) 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 VO sub(2) associated with reduced mechanical efficiency, exercise led to the attainment of similar levels of effort in both groups. In summary, central AT sub(1)-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 AT sub(1)-receptors shifts energy balance during graded exercise, similarly to situations of higher and premature sympathetic activation.