Influence of AT₁ blockers on obesity and stress-induced eating of cafeteria diet

Based on findings that treatment with AT₁ receptor blocker (ARB) prevents diet-induced obesity and that the activity of the hypothalamic-pituitary-adrenal (HPA) axis is stimulated by AngII and blocked by ARBs, we aimed to investigate whether ARB treatment can reduce stress-induced eating of cafeteria diet (CD), thus contributing to alterations in eating behavior. Sprague-Dawley rats were fed with chow or CD and treated with telmisartan (TEL, 8 mg/kg/day) or vehicle. At weeks 2 and 12, rats were stressed over five consecutive days by restraint stress (RS, 4 h) and by additional shaking at d5. Tail blood was sampled during RS to determine hormone levels. During the first period of RS, ACTH and corticosterone responses were diminished at d5 in CD- compared to chow-fed rats. Independently of feeding, TEL did not reduce stress hormones. Compared to food behavior before RS, the stress-induced CD eating increased in controls but remained unchanged in TEL-treated rats. After 12 weeks, TEL reduced weight gain and energy intake, particularly in CD-fed rats. Similar to the first RS period, corticosterone response was reduced in CD-fed rats at d5 during the second RS period. TEL did not further reduce stress hormones and did not lessen the CD eating upon RS. We conclude that CD feeding compensates for stress reactions. However, stress-induced CD eating was only reduced by TEL after short term, but not after long-term drug treatment. Thus, the potency of ARBs to lower HPA activity only plays a minor role in reducing energy intake to prevent obesity.