Thermo-afferent and Efferent Mechanisms Leading to Brown Adipose Tissue Thermogenesis in Rats Administered with Dietary Glutamate

摘要

Dietary monosodium glutamate (MSG) intake reduces body weight by increasing energy expenditure. It also causes activation of brain thermogenic areas. This information from the gut is relayed to the brain by the subdiaphragmatic vagus nerve. The effect of intragastric administration of MSG on temperature of the brown adipose tissue (T_(BAT)), body (T_b), and brain (T_(br)) was investigated. MSG application in the stomach produced an immediate increase in T_(BAT) followed by rise in T_b The rise in T_(BAT) and T_b was attenuated with propranolol pretreatment. Stimulation of the subdiaphragmatic vagus nerve increased T_(BAT), which was blocked by lidocaine. The results of the study show that dietary MSG leads to BAT thermogenesis mediated through gastric afferent and P-adrenergic efferent mechanism. This knowledge can be applied for increasing energy expenditure to control body weight and counteract hypothermia.