Resumen:
Ghrelin (Ghr), a peptide secreted from stomach and Central Nervous System, increases food intake and body weight, and may have a variety of regulatory actions related to emotional situations. The aim of this work was study intracerebroventricular Ghr effect on sweet food intake and expression of transcripts for reward peptides in hypothalamus. Adult male Albino?s Swiss mice were divided in saline (S), Ghr 0.3 and Ghr 3.0 nmol/μl. The sweet pellets intake was measured 15 min after administration, the consumption of habitual rat chow was measured during a 24 hours period and them the animal were sacrificed and their hyphotahlamus dissected to the gene study using real time PCR. The genes analyzed include dynophin, kappa-opioid receptor (KOR), my-opioid receptor (MOR) delta-opioid receptor (DOR) and neuropeptide Y (NPY). The results showed that Ghr significantly increased the numbers of sweet pellets intake in comparison to saline animals in a dose related-manner and that both Ghr doses significantly decreased the latency to start eating sweet food (F (2, 91) = 7.617, P = 0.001). The consumption of habitual rat chow during a 24 hours period only increases at the higher dose. In relation to gene expression, only Ghr 3.0 nmol/μl significantly increased expression of NPY gene (relative expression (AU S = 0.18 ± 0.01 vs. Ghr 3.0 = 0.98 ± 0.02, p <0.001), while both doses decrease dynorphin expression (AU) S = 0.58 ± 0.02 vs. Ghr 0.3 = 0.38 ± 0.03; Ghr 3.0 = 0.39 ± 0.02, p <0.001). The results suggest that Ghr affects feeding behavior in a manner that is depending on different types of food. The results indicate that Ghr is much more effective in increasing eating of sweet food than habitual rat chow and that these effects could be mediated by different molecular pathways.