The AMP kinase (AMPK) is involved in food intake regulation in the hyphotalamus, where it is modulated by orexinergic and anorexinergic peptides. Moreover AMPK has a potential role in suppression inflammatory responses that represents a risk for overnutrition-related diseases. The aim of the present work was to study the effects of a lard high-fat diet on the expression of AMPK in the hypothalamus after different time length of treatment. 12 groups of 5 rats each were divided as follows: 6 groups were fed a high-fat diet ad libitum for respectively 5, 7, 14, 42, 84 or 126 days; the other 6 groups were fed with the standard chow diet for the same periods (5, 7, 14, 42, 84, or 126 days). Food comsuption and body weight were monitored during the treatment. The hyphotalamus was sectioned and the levels of AMPKa and p-AMPKa protein were analyzed by Western blot and immunohistochemistry.

The results showed a significant increase in body weight of the animals treated with lard high-fat diet compared to standard diet after 2 weeks of treatment. pAMPKa was increased only after 6 weeks of the lard high-fat diet; it was expressed in different area of the hypothalamus, in particular in the arcuate, ventro-medial and lateral hypothalamus. These data suggest that the lard high-fat diet modifies the AMPK expression in the hyphotalamus only after a long treatment.