title: Effect of hyperphenylalaninemia chemically induced on in vitro incorporation of 32P into cytoskeletal proteins from cerebral cortex of developing rats.
abstract: We studied the effect of hyperphenylalaninemia on in vitro incorporation of 32P into cytoskeletal proteins from cerebral cortex of rats by injecting l-phenylalanine plus alpha-methylphenylalanine subcutaneously from the 6th to the 14th day postpartum. Chronic hyperphenylalaninemia induced an increased in vitro phosphorylation of the 150-kDa neurofilament subunit and tubulins present in the cytoskeletal fraction at the end of the treatment and 3 days after treatment discontinuation. In addition, when in vitro phosphorylation of the cytoskeletal proteins from treated animals was performed in the presence of the drugs we observed a decreased in vitro incorporation of 32P into these proteins. Thus, the effect of l-phenylalanine plus alpha-methylphenylalanine on the endogenous protein kinase and phosphatase activities was examined and the results demonstrated that these drugs have an inhibitory effect on calcium/calmodulin-dependent protein kinase II and protein phosphatase type 1.
authors.affiliation: Departamento de Bioquímica, Instituto de Biociências, Universidade Federal do Rio Grande do Sul, Porto Alegre RS, Brazil.
authors.forename: M S
authors.initials: MS
authors.lastname: de Freitas
authors.forename: A
authors.initials: A
authors.lastname: de Mattos-Dutra
authors.forename: N
authors.initials: N
authors.lastname: Schroder
authors.forename: C M
authors.initials: CM
authors.lastname: Wannmacher
authors.forename: R
authors.initials: R
authors.lastname: Pessoa-Pureur
mesh_terms: D000818:Animals; D000831:Animals, Newborn / Q000254:growth & development*; D054732:Calcium-Calmodulin-Dependent Protein Kinase Type 2; D017871:Calcium-Calmodulin-Dependent Protein Kinases / Q000187:drug effects*; D002540:Cerebral Cortex / Q000187:drug effects*; D003599:Cytoskeleton / Q000187:drug effects*; D066298:In Vitro Techniques; D010649:Phenylalanine / Q000494:pharmacology*; D010766:Phosphorylation / Q000187:drug effects; D051381:Rats; D017208:Rats, Wistar
chemical_list: D010649:Phenylalanine; D054732:Calcium-Calmodulin-Dependent Protein Kinase Type 2; D017871:Calcium-Calmodulin-Dependent Protein Kinases