Specific role of dietary fat in modifying cardiovascular and locomotor activity 24-h rhythms
Data(s) |
01/01/2015
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Resumo |
Meal-fed conscious rabbits normally exhibit postprandial elevation in blood pressure, heart rate (HR) and locomotor activity, which is abolished by consumption of a high-fat diet (HFD). Here, we assessed whether the cardiovascular changes are attributable to the increased caloric intake due to greater fat content or to hyperphagia. Rabbits were meal-fed during the baseline period then maintained on either an ad libitum normal fat diet (NFD) or ad libitum HFD for 2 weeks. Blood pressure, HR and locomotor activity were measured daily by radio-telemetry alongside food intake and body weight. Caloric intake in rabbits given a NFD ad libitum rose 50% from baseline but there were no changes in cardiovascular parameters. By contrast, HR increased by 10% on the first day of the ad libitum HFD (p<0.001) prior to any change in body weight while blood pressure increased 7% after 4d (p<0.01) and remained elevated. Baseline 24-h patterns of blood pressure and HR were closely associated with mealtime, characterised by afternoon peaks and morning troughs. When the NFD was changed from meal-fed to ad libitum, blood pressure and HR did not change but afternoon activity levels decreased (p<0.05). By contrast, after 13d ad libitum HFD, morning HR, blood pressure and activity increased by 20%, 8% and 71%, respectively. Increased caloric intake specifically from fat, but not as a result of hyperphagia, appears to directly modulate cardiovascular homeostasis and circadian patterns, independent of white adipose tissue accumulation. |
Identificador | |
Idioma(s) |
eng |
Publicador |
Taylor & Francis |
Relação |
http://dro.deakin.edu.au/eserv/DU:30074172/armitage-specificroleofdietary-2015.pdf http://www.dx.doi.org/10.3109/07420528.2015.1032414 |
Direitos |
2015, Informa Healthcare USA |
Palavras-Chave | #24-h rhythm #blood pressure #heart rate #high-fat diet #obesity #rabbits |
Tipo |
Journal Article |