Serotonin turnover in discrete hypothalamic nuclei and mesencephalic raphe nuclei of young and adult spontaneously hypertensive rats.
Serotonin levels and turnover were analyzed in discrete forebrain and mesencephalic nuclei of young (4-week-old) and adult (14-week-old) spontaneously hypertensive rats and age-matched normotensive control Wistar Kyoto rats. Most changes observed were age-dependent, and occurred only in young, early hypertensive rats. Both serotonin levels and the accumulation rate of 5-hydroxy-tryptophan after L-amino acid decarboxylase inhibition were higher in the nuclei periventricularis and paraventricularis of the hypothalamus of young hypertensive rats than in controls. In addition, 4-week-old spontaneously hypertensive rats showed higher 5-hydroxytryptophan accumulation rates in the nuclei supraopticus and dorsomedialis of the hypothalamus than controls. The only difference in serotonin metabolism found in adult hypertensive rats was high serotonin concentration in the median eminence of the hypertensive animals. Our results suggest the presence of anatomically specific, age-dependent alterations in serotonin metabolism, localized to selected hypothalamic nuclei in young hypertensive rats. These data support a role for the hypothalamic serotonin in the development of the spontaneous (genetic) hypertension in the rat.
D006916:5-Hydroxytryptophan / Q000378:metabolism; D000375:Aging; D000818:Animals; D006897:Hydroxyindoleacetic Acid / Q000378:metabolism; D006973:Hypertension / Q000378:metabolism* / Q000503:physiopathology; D007031:Hypothalamus / Q000378:metabolism* / Q000503:physiopathology; D007700:Kinetics; D008297:Male; D010293:Pargyline / Q000494:pharmacology; D011903:Raphe Nuclei / Q000378:metabolism* / Q000503:physiopathology; D051381:Rats; D011918:Rats, Inbred SHR; D011921:Rats, Inbred WKY; D012701:Serotonin / Q000378:metabolism*; D013045:Species Specificity
D012701:Serotonin; D006897:Hydroxyindoleacetic Acid; D010293:Pargyline; D006916:5-Hydroxytryptophan