Neurotoxin effects on oxytocin, vasopressin and somatostatin in discrete rat brain areas.
Monosodium-L-Glutamate (MSG) produces lesions to monoaminergic and peptidergic neurons in several brain areas. The present study examined the effect of neonatal MSG treatment on oxytocin (OXY), arginine-vasopressin (AVP) and somatostatin (SRIF) concentrations in several discrete brain areas of adult rats. OXY increased in the suprachiasmatic and arcuate nuclei and median eminence (ME) and decreased in the paraventricular nucleus of MSG-treated rats. MSG treatment caused AVP to increase in the arcuate nucleus and ME and decrease in the supraoptic nucleus. SRIF decreased following neonatal MSG treatment in both the ME and neurointermediate pituitary lobe. The results demonstrate that the effects of neonatal MSG treatment on neuropeptide content are not just limited to the arcuate nucleus. Furthermore, taken together with previous results, the data suggest that these changes may be indicative of functional deficits in the neuronal activity of some of these peptidergic neurons which, in turn, may be responsible for the abnormal secretion of several pituitary hormones observed in MSG-treated animals.
D000818:Animals; D000831:Animals, Newborn; D001127:Arginine Vasopressin / Q000378:metabolism*; D001921:Brain / Q000187:drug effects / Q000378:metabolism*; D005260:Female; D005971:Glutamates / Q000633:toxicity*; D008297:Male; D010121:Oxytocin / Q000378:metabolism*; D010904:Pituitary Gland, Posterior / Q000187:drug effects / Q000378:metabolism; D051381:Rats; D012970:Sodium Glutamate / Q000633:toxicity*; D013004:Somatostatin / Q000378:metabolism*; D014018:Tissue Distribution
D005971:Glutamates; D001127:Arginine Vasopressin; D010121:Oxytocin; D013004:Somatostatin; D012970:Sodium Glutamate