title: Dihydropteridine reductase activity in the brainstem of intrauterine growth-restricted rats.
abstract: The aim of this study was to determine whether intrauterine growth restriction produces an increase of dihydropteridine reductase activity as a compensatory mechanism that maintains the necessary concentration of cofactor, tetrahydrobiopterin, during accelerated brain serotonin biosynthesis. Intrauterine growth-restricted offspring and controls were used. On days 1, 10, 15 and 21 of life, the brainstem was dissected and l-tryptophan, serotonin, tryptophan-5-hydroxylase and dihydropteridine reductase activities were determined. Intrauterine growth-restricted pups showed a significant increase of l-tryptophan, 5-hydroxytryptamine, tryptophan-5-hydroxylase and also dihydropteridine activity in the brainstem in comparison to normal pups. These results confirm that intrauterine growth restriction produces an increase of serotonin biosynthesis in the brainstem. This is accompanied by an increase in dihydropteridine activity that appears to be a compensatory mechanism to maintain sufficient tetrahydrobiopterin for the donation of electrons during the accelerated synthesis of brain serotonin in intrauterine growth-restricted rats.
authors.affiliation: Laboratory of Molecular Pathology, Cardiology Hospital, National Medical Center (CMN-SXXI), Mexican Institute of Social Security, Mexico City 06725, Mexico. willisga@prodigy.net.mx
authors.forename: Gabriel
authors.initials: G
authors.lastname: Manjarrez-Gutierrez
authors.forename: Misael
authors.initials: M
authors.lastname: Gonzalez-Ramirez
authors.forename: Alfonso
authors.initials: A
authors.lastname: Boyzo-Montes de Oca
authors.forename: Jorge
authors.initials: J
authors.lastname: Hernandez-Rodriguez
mesh_terms: D000818:Animals; D001708:Biopterins / Q000031:analogs & derivatives / Q000378:metabolism; D001933:Brain Stem / Q000201:enzymology*; D031204:Caloric Restriction; D004093:Dihydropteridine Reductase / Q000378:metabolism*; D005260:Female; D005317:Fetal Growth Retardation; D008297:Male; D009752:Nutritional Status; D011247:Pregnancy; D051381:Rats; D017208:Rats, Wistar; D012701:Serotonin / Q000096:biosynthesis; D014365:Tryptophan Hydroxylase / Q000378:metabolism
chemical_list: D001708:Biopterins; D012701:Serotonin; D014365:Tryptophan Hydroxylase; D004093:Dihydropteridine Reductase; C003402:sapropterin