Chronic blockade of angiotensin AT1receptors improves cardinal symptoms of metabolic syndrome in diet‐induced obesity in rats

Abstract

AT₁ receptor antagonists decrease body weight gain in models of murine obesity. However, fewer data are available concerning the anti-obesity effects of these antagonists, given as a treatment after obesity had been established. In spontaneously hypertensive rats, obesity was established by cafeteria diet (CD) feeding for 19 weeks. Rats were then were treated with telmisartan (8 mg·kg⁻¹·d⁻¹) or amlodipine (10 mg·kg⁻¹·d⁻¹; serving as blood pressure control) or telmisartan + amlodipine (2 + 10 mg·kg⁻¹·d⁻¹; to control for dose-dependency) for 17 weeks. Rats receiving only chow (C(chow)) or CD-fed rats treated with vehicle (C(CD)) served as controls. The CD feeding induced obesity, hyperphagia, hyperlipidaemia, and leptin and insulin resistance. Telmisartan reduced the CD-induced increase in body weight and abdominal fat mass. Whereas energy intake was higher rather than lower, the respiratory ratio was lower. After telmisartan, leptin-induced energy intake was reduced and respiratory ratio was increased compared with C(CD) rats. Telmisartan also decreased plasma levels of triglycerides, free fatty acids and low-density lipoprotein. Amlodipine alone or the combination telmisartan + amlodipine did not affect body weight and eating behaviour. Telmisartan, but not amlodipine and telmisartan + amlodipine, improved glucose utilization. The decrease in BP reduction was almost the same in all treatment groups. Telmisartan exerted anti-obesity effects and restored leptin sensitivity, given as a treatment to rats with obesity. Such effects required high doses of telmisartan and were independent of the decrease in blood pressure.