title: Regional changes in monoamine metabolism in the aging constant estrous rat.
abstract: Studies were undertaken to determine levels of monoamines and their metabolites in brain regions in young (3-4 months) normally cycling and old (25-26 month) constant estrous female rats. Dopamine (DA) concentrations were reduced in old rats in the median eminence (ME), medial basal hypothalamus (MBH), preoptic area-anterior hypothalamus (POA-AH) and the striatum. Similarly, concentrations of dihydroxyphenylacetic acid (DOPAC), the major acid metabolite of DA, were reduced significantly in all 4 regions. In the ME, a strong positive correlation was observed between DA and DOPAC concentrations in both young and old rats. Concentrations of norepinephrine (NE) were reduced in old rats in the MBH and POA-AH but not in the ME or striatum. Concentrations of serotonin (5HT) and its major metabolite, 5-hydroxyindoleacetic acid (5HIAA) were generally unchanged with age in all of the regions examined. These studies indicate the age-related regional alterations in DA and 5HT metabolism can be monitored by methods which quantitate monoamines and their metabolites.
mesh_terms: D015102:3,4-Dihydroxyphenylacetic Acid / Q000378:metabolism; D000375:Aging; D000818:Animals; D001921:Brain / Q000378:metabolism*; D003342:Corpus Striatum / Q000378:metabolism; D004298:Dopamine / Q000378:metabolism; D004971:Estrus; D005260:Female; D006719:Homovanillic Acid / Q000378:metabolism; D006897:Hydroxyindoleacetic Acid / Q000378:metabolism; D007033:Hypothalamus, Middle / Q000378:metabolism; D008473:Median Eminence / Q000378:metabolism; D009474:Neurons / Q000378:metabolism; D018377:Neurotransmitter Agents / Q000378:metabolism*; D009638:Norepinephrine / Q000378:metabolism; D011247:Pregnancy; D011301:Preoptic Area / Q000378:metabolism; D051381:Rats; D012701:Serotonin / Q000378:metabolism; D009435:Synaptic Transmission
chemical_list: D018377:Neurotransmitter Agents; D015102:3,4-Dihydroxyphenylacetic Acid; D012701:Serotonin; D006897:Hydroxyindoleacetic Acid; D004298:Dopamine; D009638:Norepinephrine; D006719:Homovanillic Acid