Glutamic acid and sodium levels in the nucleus arcuatus of the hypothalamus of adult and infant guinea pigs after oral monosodium glutamate

Monosodium glutamate (MSG) administered orally at 4 g/kg body weight (b.wt.) as a 20% solution (w/v) to 55-60-day-old guinea pigs and at 2 g/kg b.wt. as a 20% solution (w/v) to 3-day-old guinea pigs did not increase glutamie acid (GA) or sodium levels in the nucleus arcuatus of the hypothalamus (NAH) or in the thalamus lateralis (TL). Sodium chloride given by gavage at doses of sodium equimolar to MSG resulted in an increase of sodium content only in the NAH of infant guinea pigs.