Effect of orally Monosodium Glutamate (MSG) administration on regulation of appetite

A. P. GARCÍA; C. ARIZNAVARRETA; M HERMANUSSEN; J. A. F. TRESGUERRES

Glasgow

Encuentro; Life Science 2007. The first joint meeting of the Biochemical Society, the British Pharmacological Society and the Physiological Society; 2007

ABSTRACT It is well known that parenteral neonatal monosodium glutamate (MSG) administration has toxic effects on arcuate nucleus neurons, leading to significant brain lesions, neuroendocrine disturbances and obesity (1-3). The present study was undertaken to investigate whether oral MSG administration was able to produce the same effect. Thirty pregnant Wistar rats were separated in three groups; the first two groups received specific diets containing 0, (control group, CT group) or 4 g MSG/Kg BW, (oral treatment group, OT group) from day 14th of pregnancy onwards. The third group of mothers received standard rat chow, but their offspring was neonatally injected with MSG (4mg/g BW) on alternate days for the first 10 postnatal days (day 2, 4, 6, 8, 10), (parenteral treatment group, PT group). The other groups received saline injections on the same days. After weaning, MSG feeding was continued in the first two groups at the same concentrations in the offspring until 6 months of life. Body weight of animals as well as food intake were measure periodically. Half of the pups were sacrificed at 1 month and the rest at the 6 month of life. Blood samples were collected for Leptin radioimmunoassay determination. Hypothalamus were collected as well for neuropeptide Y (NPY) and Leptin receptor (R-leptin) mRNA expression determinations using real time PCR. Even though no changes were observed in body weight in PT group with respect to control group at one month life, at six months life, AP group showed lower body weight and body weight gain than the other two groups (p