RESUMEN
Immunoassayable Plasma renin activity (PRA) was measured in normal subjects aged from 15 days to 15 years. A very progressive decrease of PRA with age could be demonstrated. Practical conditions for the study of PRA were defined.
Asunto(s)
Renina/sangre , Adolescente , Factores de Edad , Niño , Preescolar , Humanos , Inmunoensayo , Lactante , Recién Nacido , PubertadRESUMEN
In 112 patients with essential hypertension (HTA), free of any therapeutic and receiving the standard ward, a significant inverse relationship was found between age and plasma renin activity (PRA) and plasma aldosterone (PA), measured in the supine and upright position. Urinary epinephrine and norepinephrine were not related with age. When dividing the patients in 4 different age groups, it appeared that those younger than 30 years exhibited a significantly higher PRA and PA values and a higher frequency of borderline hypertension (45 p. 100) than the older ones (12 p. 100). So as to determine the characteristics associated with borderline HTA, it was necessary to eliminate the influence of age. This was achieved by comparing two groups of carefully age-matched patients, one with borderline HTA and the other with stable HTA. The only significant difference found was a significantly more marked increase in PRA in response to orthostatism, in patients with borderline HTA. Since renin responses to an orthostatic stress are largely mediated by renal nerves, this result suggest that borderline HTA could be associated with an increased reactivity of the sympathetic nervous system.
Asunto(s)
Hipertensión/fisiopatología , Sistema Renina-Angiotensina , Sistema Nervioso Simpático/fisiopatología , Adulto , Factores de Edad , Aldosterona/sangre , Aldosterona/orina , Presión Sanguínea , Epinefrina/orina , Femenino , Humanos , Masculino , Persona de Mediana Edad , Norepinefrina/orina , Renina/sangreAsunto(s)
Neoplasias de las Glándulas Suprarrenales/diagnóstico , Catecolaminas/orina , Hidroxilaminas/orina , Feocromocitoma/diagnóstico , Ácido Vanilmandélico/orina , Neoplasias de las Glándulas Suprarrenales/cirugía , Neoplasias de las Glándulas Suprarrenales/orina , Adulto , Dieta , Epinefrina/orina , Humanos , Hipertensión/orina , Métodos , Persona de Mediana Edad , Norepinefrina/orina , Feocromocitoma/cirugía , Feocromocitoma/orina , Periodo PosoperatorioAsunto(s)
Gasto Cardíaco , Vasos Coronarios , Animales , Perros , Electrocardiografía , Corazón/fisiología , Contracción Muscular , Arterias TorácicasAsunto(s)
Sistema Cromafín/metabolismo , Epinefrina/biosíntesis , Norepinefrina/metabolismo , Corticoesteroides/fisiología , Glándulas Suprarrenales/metabolismo , Animales , Isótopos de Carbono , Cromatografía en Papel , Femenino , Fluorescencia , Histocitoquímica , Masculino , Metilación , Tiburones , Transferasas/biosíntesisRESUMEN
The motor effects of DOPA and Dopamine on the isolated rat duodenum in vitro have been studied by establishing successive dose- response curves. These effects are either excitatory or inhibitory according to the concentrations used. In every case they are of small amplitude. The inhibitory effects do not exist in the presence of alpha, and beta blocking agents. The excitatory effects are suppressed by using a serotoninergic blocking agent.
Asunto(s)
Dihidroxifenilalanina/farmacología , Dopamina/farmacología , Duodeno/fisiología , Motilidad Gastrointestinal/efectos de los fármacos , Animales , Relación Dosis-Respuesta a Droga , Duodeno/efectos de los fármacos , Técnicas In Vitro , Masculino , RatasRESUMEN
The study of the direct action of dopamine on the rat duodenum serotoninergic receptors and the parallelism of the results obtained with the motricity curves of this organ in vitro allows us to conclude that dopamine recognizes serotoninergic receptors : the excito- motor effect observed with certain dopamine concentrations on the isolated rat duodenum may be attributed to this action of dopamine on serotoninergic receptors. These results seem in agreement with the observations of other authors.