Monosodium glutamate exposure in the neonate alters hypothalamic and pituitary neuropeptide levels in the adult.
Administration of monosodium glutamate (MSG) during the neonatal period in rats produced differential effects on the contents of various neuropeptides in the hypothalamus: beta-endorphin (beta-E) level was reduced by 70% while substance P (SP), neurotensin (NT) and Met5-enkephalin (ME) levels were not significantly changed (ME content of male rats was slightly reduced). The contents of ME, SP and NT in striatum and hippocampus were also unaffected by the same treatment. Male rats contain higher pituitary content of beta-endorphin-like immunoreactivity (beta-ELI) than female rats. MSG treatment reduced the pituitary content of beta-ELI and abolished the sex difference in beta-ELI level seen in the control rats. MSG treatment in the neonates by eliminating beta-E neurons while sparing ME neurons in the brain may be a useful tool for studying the different functions of these two separate opioid peptides.
D000818:Animals; D004723:Endorphins / Q000378:metabolism; D004744:Enkephalin, Methionine; D004745:Enkephalins / Q000378:metabolism; D005260:Female; D005971:Glutamates / Q000494:pharmacology*; D007031:Hypothalamus / Q000187:drug effects*; D008297:Male; D009419:Nerve Tissue Proteins / Q000378:metabolism*; D009496:Neurotensin / Q000378:metabolism; D010902:Pituitary Gland / Q000187:drug effects*; D011247:Pregnancy; D011297:Prenatal Exposure Delayed Effects; D051381:Rats; D012737:Sex Factors; D012970:Sodium Glutamate / Q000494:pharmacology*; D013373:Substance P / Q000378:metabolism
D004723:Endorphins; D004745:Enkephalins; D005971:Glutamates; D009419:Nerve Tissue Proteins; D013373:Substance P; D009496:Neurotensin; D004744:Enkephalin, Methionine; D012970:Sodium Glutamate