Programação pré-natal de hipertensão arterial na vida adulta / Prenatal programming of adult arterial hypertension

Na busca da melhor compreensão da origem das doenças cardiovasculares, uma importante linha de investigação surgiu a partir da demonstração da associação entre o baixo peso ao nascer e o desenvolvimento de hipertensão foi a base para a formulação da hipótese de que doenças cardiovasculares manifestadas na idade adulta podem ser programadas a partir de insultos ocorridos no período pré natal.Diversos modelos experimentais apóiam esta teoria. Em animais de laboratório, estudos com desnutrição induzida durante a gestação resultaram em animais adultos com níveis mais elevados de pressão arterial do que os controles...

Regulation of nephron acidification by costicosteroids

The present paper reviews work from our laboratories evaluating the importance of adrenal cortical hormones in acidification by proximal and cortical distal tubules. Proximal acidification was determined by stationary microperfusion, and measurement of bicarbonate reabsorption using luminal pH determination was performed with H+ -ion-sensitive microelectrodes. Rats were adrenalectomized (ADX) 48 h before the experiments, and corticosteroids (aldosterone(A), corticosterone(B), and 18-OH corticosterone (18-OH-B)) were injected intramuscularly 100 and 40 min before the experiments. In ADX rats stationary pH increased significantly to 7.03 as compared to sham-operated rats (6.78). Bicarbonate reabsorption decreased from 2.65 + 0.18 in sham-operated rats to 0.50 + 0.07 mmol cm-2 S(-1) after ADX. The administration of the three hormones stimulated proximal tubule acidification, reaching, however, only 47.2 per cent of the sham values in aldosterone-treated rats. Distal nephron acidification was studied by measuring urine minus blood pCO2 differences (U-B pCO2) in bicarbonate-loaded rats treated as above. This pCO2 difference is used as a measure of the distal nephron ability to secrete H+ ions into an alkaline urine. U-B pCO2 decreased significantly from 39.9 + 1.26 to 11.9 + 1.99 mmHg in ADX rats. When corticosteroids were given to ADX rats before the experiment, U-B pCO2 increased significantly, but reached control levels only when aldosterone (two 3-mug doses per rat) plus corticosterone (220 mug) were given together. In order to control for the effect of aldosterone on distal transepithelial potential difference one group of rats was treated with amiloride, which blocks distal sodium channels. Amiloride-treated rats still showed a significant reduction in U-B pCO2 after ADX. Only corticosterone and 18-OH-B but not aldosterone increased U-B pCO2 back to the levels of sham-operated rats. These results show that corticosteroids stimulate renal tubule acidification both in proximal and distal nephrons and provide some clues about the mechanism of action of these steroids.

Involvement of adrenal hormones in tissue respiration of sub-tropical hibernating and non-hibernating species of frogs.

Effects of norepinephrine (NE), epinephrine (EP), corticosterone and cortisol were studied both in vivo and in vitro on the rate of oxygen consumption of tissues (liver, skeletal muscle and kidney) of sub-tropical Indian frogs Rana limnocharis (a hibernating species) and Rana cyanophlyctis (a non-hibernating species) exposed to natural climatic conditions during winter and summer/rainy seasons. Further, the effects of NE and EP were also studied in vitro in the presence of specific beta- and alpha-adrenergic antagonists (propranolol and prazosin). NE, EP and corticosterone, when administered in vivo or in vitro, significantly stimulated the respiratory rate of the tissues of both the species irrespective of the seasons/temperature. Results suggest that NE, EP and corticosterone are directly involved in regulation of the energy metabolism of both hibernating and non-hibernating species of sub-tropical frogs. The calorigenic action of NE and EP seems to be mediated by both beta- and alpha-adrenergic receptors. However, the temporal involvement of beta- and alpha-adrenergic receptors seems to be tissue-dependent.

El sistema nervioso central y el sistema neuroendocrino en la regulacion de la respuesta inmune / The central nervous system and the neuroendocrine system in the regulation of the immune response

Existe actualmente una orientación definida hacia el estudio de los fenómeno psiconeuro inmunorregulatorios. Diversos modelos experimentales han demonstrado: a) la participación del stress y factores psicosociales y el sistema nervioso central en la regulación de la respuesta inmune; b) una inervación bien desarrollada por el sistema nervioso autónomo en los órganos linféticos; c) la presencia de receptores para mediadores neuroendócrinos en células mononucleares periféricas; d) la actividad de neuropéptidos, hormonas y neurotransmisores en la activación y acción linfocitaria; e) la producción de sustancias neuroendócrinas por linfocitos; f) la existencia de vías de retroalimentación por parte del sistema inmune. En nuestro laboratorio hemos contribuído a esta orientación con la descripción de a) la actividad regulatoria de diversas sustancias neuroendócrinas sobre la producción de interferón-gama; b) la caracterización de la inmunorregulación ejercida por el sistema colinérgico muscarínico; c) la descripción de la actividad in vitro de las indolaminas serotonina y melatonina sobre el sistema inmune y la producción de estas indolaminas por linfocitos y monocitos, constituyendo un modelo de regulación parácrina. Actualmente se están ampliando las investigaciones desarrollando además líneas de estudios integrativas de la función del sistema nervioso central en la regulación del sistema inmune an animales y humanos

Caracterización estructural y citoquimica de las glandulas salivales de ratas adrenalectomizadas / Structural and cytochemical characterization of the salivary glands of adrenalectomized rats

Considerando que el rol de ciertas hormonas adrenales sobre las glándulas salivales no ha sido suficientemente aclarado, decidimos el estudio de los cambios estructurales y citoquímicos que la adrenalectomía causa sobre estos órganos. El estudo estructural y citoquímico en submaxilar muestra modificaciones del parénquima glandular. Estos cambios se mantienen desde 7 hasta 45 días. No se encouetran alteraciones significativas en sublingual. Los resultados obtenidos sugieren que se producirían modificaciones en los productos de secreción de estas glándulas

Sarna noruega em un paciente tratado con corticoides sistemicos / Scabies Norwegian command post a patient dealt with sistemic corticoids

Se presenta un caso de sarna noruega en un enfermo que previamente fue tratado con corticoides sistemicos por largo tiempo. El estudio inmujnologico particado no ofrecio resultados concluyentes. El tratamiento fue eficaz con los farmacos antiescabioticos habituales y el empleo de querotoliticos en las zonas hiperqueratosicas, si bien hubo que lamentar dos recidivas en forma de sarna humana tipica.

Effect of Hypophysectomy, Adrenalectomy, and Thyroidectomy on the Beta-Cells of the Islets of Langerhans of the Pancreas

Prolonged administration of anterior hypophyseal, adrenocortical, or thyroid hormones is known to cause degeneration, degranulation and necrosis of the beta-cells in the Langerhans islets of the pancreas. However, the effects of extirpation of these endocrine glands upon the Langerhans islets has not been reported, a1though it is known that removal of any of these glands bring about hypoglycemia, decreased tissue uptake of glucose, and increased tissue sensitivity to insulin. The present investigation is studies of the morphologic alterations of the beta-cells in the Langerhans islets following hypophysectomy, adrenalectomy, or thyroidectomy in rats. Hypophysectomy, adrenalectomy, and thyroidectomy, all induce similar morphologic alterations in the beta-cells of the islets. These consist of increased beta-cell population, the accumlnation of beta-granules, and atrophy of the individual betacell. Therefore, these changes are considered to be not specific following the withdrawal of specific hormones but a common effect of the hypoglycemia due to removal of the hypophysis, adrenals, or thyroid glands. A similar common degeneration of the beta-cells due to hyperglycemia occurs when hormones of these endocrine glands are given excessively.