Food restriction increases the cardiovascular response evoked by angiotensin‐[1–10] and angiotensin‐[1–7] in female Fischer rats

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Anorexia is associated with cardiovascular dysfunction including hypotension and cardiac arrhythmias. In a rat model of food restriction (FR) we previously demonstrated that the activity of endothelial α1 adrenergic receptors and brain type 1 angiotensin receptors were increased. The aim of this study was to determine the role of the angiotensin (Ang)‐[1–7] and Ang‐[I‐10] in the brain. Female Fischer rats (220g, 4 mo) were maintained for 14 days on a FR diet, that was 40% of the control group (C) food intake. Cannulas were implanted in the lateral ventricle (LV) on day 7. On day 14, the animals were catheterized with a polyethylene tube in the femoral artery for recording of mean arterial pressure (MAP) and heart rate (HR). After 14 days, MAP (mmHg) [C: 105±1, n=35 vs. FR: 102±2, n=36; p<0.05] and HR (bpm) [C: 386±5, n=35 vs. FR: 353±8, n=36, p<0.001] were reduced in the FR. Injection of Ang‐[1–7] caused a greater increase in MAP (Δ mm Hg) in the FR compared to C group (25pmol) [C: Δ −2±1, n=8 vs. FR: Δ 7±1, n=10; p<0.05]. Moreover, there was a greater increase in HR (Δ bpm) in the FR compared to the C group [C: Δ 9±3, n=8 vs FR: Δ 29±9, n=10; p<0.05]. Injection of Ang‐[1–10] caused a greater increase in MAP (Δ mm Hg) in the FR compared to C group (25pmol) [C: 5±1, n=7 vs. FR: 13±2, n=7; p<0.005]; however, there was no effect on HR. This Ang‐[1–10]‐induced increase in MAP was attenuated by administering captopril into the LV, in both the FR and C groups, suggesting this increase in MAP was mediated by angiotensin converting enzyme. These results suggest that increased Ang‐[1–7] and Ang‐[1–10] activity in the brain play a role in the increased sympathetic activity observed in anorexia.Support or Funding InformationNIH 1R01HL119380 (KS)UFOP (AS)CAPES (AS)