title: Chronic caffeine intake decreases circulating catecholamines and prevents diet-induced insulin resistance and hypertension in rats.
abstract: We tested the hypothesis that long-term caffeine intake prevents the development of insulin resistance and hypertension in two pathological animal models: the high-fat (HF) and the high-sucrose (HSu) diet rat. We used six groups of animals: control; caffeine-treated (Caff; 1 g/l in drinking water during 15 d); HF; caffeine-treated HF (HFCaff); HSu; caffeine-treated HSu (HSuCaff). Insulin sensitivity was assessed using the insulin tolerance test. Blood pressure, weight gain, visceral fat, hepatic glutathione, plasma caffeine, insulin and NO, and serum NEFA and catecholamines were measured. Caffeine reversed insulin resistance and hypertension induced by both the HF and HSu diets. In the HF-fed animals caffeine treatment restored fasting insulin levels to control values and reversed increased weight gain and visceral fat mass. In the HSu group, caffeine reversed fasting hyperglycaemia and restored NEFA to control values. There were no changes either in plasma NO or in hepatic glutathione levels. In contrast, caffeine totally prevented the increase in serum catecholamines induced by HF and HSu diets. To test the hypothesis that inhibition of the sympathetic nervous system prevents the development of diet-induced insulin resistance we administered carvedilol, an antagonist of β1, β2 and also α1 adrenoceptors, to HF and HSu rats. Carvedilol treatment fully prevented diet-induced insulin resistance and hypertension, mimicking the effect of caffeine. We concluded that long-term caffeine intake prevented the development of insulin resistance and hypertension in HF and HSu models and that this effect was related to a decrease in circulating catecholamines.
authors: Centro de Estudos de Doenças Crónicas (CEDOC), Departamento de Farmacologia, Faculdade de Ciências Médicas, Universidade Nova de Lisboa, Campo Mártires da Pátria, 130, 1169-056 Lisbon, Portugal.
authors: Silvia V
authors: SV
authors: Conde
authors: Tiago
authors: T
authors: Nunes da Silva
authors: Constancio
authors: C
authors: Gonzalez
authors: Miguel
authors: M
authors: Mota Carmo
authors: Emilia C
authors: EC
authors: Monteiro
authors: Maria P
authors: MP
authors: Guarino
mesh_terms: D050154:Adiposity; D018674:Adrenergic Antagonists / Q000627:therapeutic use; D000818:Animals; D001835:Body Weight; D002110:Caffeine / Q000008:administration & dosage / Q000097:blood / Q000627:therapeutic use*; D002227:Carbazoles / Q000627:therapeutic use; D000077261:Carvedilol; D002395:Catecholamines / Q000097:blood*; D004041:Dietary Fats / Q000009:adverse effects*; D019422:Dietary Sucrose / Q000009:adverse effects*; D005230:Fatty Acids, Nonesterified / Q000097:blood; D005260:Female; D006943:Hyperglycemia / Q000209:etiology / Q000517:prevention & control; D006973:Hypertension / Q000209:etiology / Q000517:prevention & control*; D007328:Insulin / Q000097:blood; D007333:Insulin Resistance; D050152:Intra-Abdominal Fat / Q000033:anatomy & histology; D008297:Male; D024821:Metabolic Syndrome / Q000097:blood / Q000209:etiology / Q000517:prevention & control*; D011412:Propanolamines / Q000627:therapeutic use; D051381:Rats; D017208:Rats, Wistar
chemical_list: D018674:Adrenergic Antagonists; D002227:Carbazoles; D002395:Catecholamines; D004041:Dietary Fats; D019422:Dietary Sucrose; D005230:Fatty Acids, Nonesterified; D007328:Insulin; D011412:Propanolamines; D000077261:Carvedilol; D002110:Caffeine