title: L-Arginine metabolism in cardiovascular and renal tissue from hyper- and hypothyroid rats.
abstract: This study assessed the effects of thyroid hormones on the enzymes involved in l-arginine metabolism and the metabolites generated by the different metabolic pathways. Compounds of l-arginine metabolism were measured in the kidney, heart, aorta, and liver of euthyroid, hyperthyroid, and hypothyroid rats after 6 weeks of treatment. Enzymes studied were NOS isoforms (neuronal [nNOS], inducible [iNOS], and endothelial [eNOS]), arginases I and II, ornithine decarboxylase (ODC), ornithine aminotransferase (OAT), and l-arginine decarboxylase (ADC). Metabolites studied were l-arginine, l-citrulline, spermidine, spermine, and l-proline. Kidney heart and aorta levels of eNOS and iNOS were augmented and reduced (P < 0.05, for each tissue and enzyme) in hyper- and hypothyroid rats, respectively. Arginase I abundance in aorta, heart, and kidney was increased (P < 0.05, for each tissue) in hyperthyroid rats and was decreased in kidney and aorta of hypothyroid rats (P < 0.05, for each tissue). Arginase II was augmented in aorta and kidney (P < 0.05, for each tissue) of hyperthyroid rats and remained unchanged in all organs of hypothyroid rats. The substrate for these enzymes, l-arginine, was reduced (P < 0.05, for all tissues) in hyperthyroid rats. Levels of ODC and spermidine, its product, were increased and decreased (P < 0.05) in hyper- and hypothyroid rats, respectively, in all organs studied. OAT and proline levels were positively modulated by thyroid hormones in liver but not in the other tissues. ADC protein levels were positively modulated by thyroid hormones in all tissues. According to these findings, thyroid hormone treatment positively modulates different l-arginine metabolic pathways. The changes recorded in the abundance of eNOS, arginases I and II, and ADC protein in renal and cardiovascular tissues may play a role in the hemodynamic and renal manifestations observed in thyroid disorders. Furthermore, the changes in ODC and spermidine might contribute to the changes in cardiac and renal mass observed in thyroid disorders.
authors.affiliation: Instituto de Investigación Biosanitaria ibs. Granada 18012, Spain. Hospitales Universitarios de Granada. Universidad de Granada, Granada 18012, Spain isabelrg@ugr.es.
authors.forename: Isabel
authors.initials: I
authors.lastname: Rodríguez-Gómez
authors.affiliation: Departamento de Fisiología, Facultad de Medicina, Grenada 18012, Spain.
authors.forename: Juan N
authors.initials: JN
authors.lastname: Moliz
authors.affiliation: Centro de Instrumentación Científica de la Universidad de Granada, Granada 18003, Spain.
authors.forename: Andrés
authors.initials: A
authors.lastname: Quesada
authors.affiliation: Centro de Instrumentación Científica de la Universidad de Granada, Granada 18003, Spain.
authors.forename: Sebastian
authors.initials: S
authors.lastname: Montoro-Molina
authors.affiliation: Instituto de Investigación Biosanitaria ibs. Granada 18012, Spain. Hospitales Universitarios de Granada. Universidad de Granada, Granada 18012, Spain.
authors.forename: Pablo
authors.initials: P
authors.lastname: Vargas-Tendero
authors.affiliation: Instituto de Investigación Biosanitaria ibs. Granada 18012, Spain. Hospitales Universitarios de Granada. Universidad de Granada, Granada 18012, Spain.
authors.forename: Antonio
authors.initials: A
authors.lastname: Osuna
authors.affiliation: Centro de Instrumentación Científica de la Universidad de Granada, Granada 18003, Spain.
authors.forename: Rosemary
authors.initials: R
authors.lastname: Wangensteen
authors.affiliation: Instituto de Investigación Biosanitaria ibs. Granada 18012, Spain. Hospitales Universitarios de Granada. Universidad de Granada, Granada 18012, Spain.
authors.forename: Félix
authors.initials: F
authors.lastname: Vargas
mesh_terms: D000818:Animals; D001011:Aorta / Q000378:metabolism; D001120:Arginine / Q000378:metabolism*; D006980:Hyperthyroidism / Q000473:pathology*; D007037:Hypothyroidism / Q000473:pathology*; D007668:Kidney / Q000378:metabolism*; D008099:Liver / Q000378:metabolism; D008297:Male; D053858:Metabolic Networks and Pathways / Q000187:drug effects; D009206:Myocardium / Q000378:metabolism*; D017208:Rats, Wistar; D013963:Thyroid Hormones / Q000378:metabolism*
chemical_list: D013963:Thyroid Hormones; D001120:Arginine
keywords: Hyperthyroidism; aorta; heart kidney; hypothyroidism; l-arginine metabolism; rat