RESUMEN
Effects of prenatal hyperhomocysteinemia on hypothalamic regulation of estrous cycles were studied in female rats. In mature rats exposed to prenatal hyperhomocysteinemia, changes in the catecholamine content in hypothalamic areas responsible for the formation of the preovulatory surge of gonadotropin-releasing hormone were revealed: the level of norepinephrine in the medial preoptic area decreased and concentration of dopamine in the median eminence with arcuate nuclei increased. Administration of melatonin attenuated the observed changes, which can be related to neuroprotective effects of this hormone determined by its antioxidant properties.
Asunto(s)
Antioxidantes/farmacología , Ciclo Estral/efectos de los fármacos , Hiperhomocisteinemia/prevención & control , Melatonina/farmacología , Fármacos Neuroprotectores/farmacología , Efectos Tardíos de la Exposición Prenatal/prevención & control , Animales , Núcleo Arqueado del Hipotálamo/efectos de los fármacos , Núcleo Arqueado del Hipotálamo/metabolismo , Núcleo Arqueado del Hipotálamo/fisiopatología , Catecolaminas/metabolismo , Femenino , Hormona Liberadora de Gonadotropina/metabolismo , Hiperhomocisteinemia/inducido químicamente , Hiperhomocisteinemia/metabolismo , Hiperhomocisteinemia/fisiopatología , Hormona Luteinizante/metabolismo , Eminencia Media/efectos de los fármacos , Eminencia Media/metabolismo , Eminencia Media/fisiopatología , Metionina/efectos adversos , Metionina/metabolismo , Norepinefrina/metabolismo , Embarazo , Efectos Tardíos de la Exposición Prenatal/inducido químicamente , Efectos Tardíos de la Exposición Prenatal/metabolismo , Efectos Tardíos de la Exposición Prenatal/fisiopatología , Área Preóptica/efectos de los fármacos , Área Preóptica/metabolismo , Área Preóptica/fisiopatología , Progesterona/metabolismo , Ratas , Ratas WistarRESUMEN
The article presents a detailed analysis of correlations between the content of a variety of biogenic amines in the hypothalamic structures responsible for the luteinizing hormone releasing hormone synthesis and secretion (the medial preoptic area and median eminence) and such independent factors as total L-homocysteine plasma level elevation induced by L-methionine loading and aging. Both a nature and a pattern of changes in oxidative stress profile were evaluated. It was shown that ageing, when compared to hyperhomocysteinemia, is a determining factor influencing biogenic amine content in the studied hypothalamic structures. Unlike antioxidant defense system profile, considerable changes in macromolecule oxidative modification were not found, which evidences a balanced activity of pro- and antioxidant systems in the hypothalamus.
Asunto(s)
Envejecimiento , Aminas Biogénicas/metabolismo , Hormona Liberadora de Gonadotropina , Homocisteína , Hiperhomocisteinemia/metabolismo , Hipotálamo , Envejecimiento/sangre , Envejecimiento/metabolismo , Animales , Femenino , Hormona Liberadora de Gonadotropina/biosíntesis , Hormona Liberadora de Gonadotropina/metabolismo , Homocisteína/sangre , Homocisteína/metabolismo , Hipotálamo/metabolismo , Hipotálamo/patología , Estrés Oxidativo/fisiología , Ratas , Ratas WistarRESUMEN
The data presented have shown the different effect of hyperhomocysteinemia (induced by 0,12-0,15 mg of methionine loading per os during 30 days) on monoamines content in hypothalamus and hippocampus of young (6-7 month) and old (20-22 month) female rats. It has been established that the level of catecholamines (noradrenaline, dopamine), 5 oxitryptamine and 5 oxyindolacetic acid in hypothalamic areas responsible for synthesis and secretion of gonadoliberin (medial preoptic area and medial eminence with arcuate nuclei) is considerable less in old animals compared with young ones. These data are in agreement with the low content of gonadoliberin found by us in medial eminence with arcuate nuclei. It has been also shown the decreased level of monoamines level in hippocampus of old rats, which does not depend on methionine loading. However in hippocampus of young animals hyperhomocysteinemia induced a noticeable reduction of noradrenaline and 5 oxyindolacetic acid, which can lead to weakening of animal's cognitive function.