RESUMEN
The effects of a single dose of cortisone acetate (5 or 10 mg/100 g body weight) on B cells were examined in young chickens. A dose-dependent increase in numbers of circulating B lymphocytes and a change in their Ig-class distribution were followed by parallel increase in splenic plasma cells and serum immunoglobulins. The higher dose of cortisone produced changes in Bmu and Bgamma cells, whereas the lower dose primarily affected Bmu cells. These steroid-induced changes were preceded by lymphocyte depletion in the cortical regions of bursal follicles, and prior bursectomy prevented steroid-induced increases in circulating B lymphocytes and tissue plasma cells. The results suggest that cortisone can induce bursal lymphocytes to migrate from the bursa and to settle subsequently in peripheral lymphoid tissues where they become mature plasma cells.
Asunto(s)
Linfocitos B/efectos de los fármacos , Pollos/inmunología , Cortisona/farmacología , Activación de Linfocitos/efectos de los fármacos , Animales , Bolsa de Fabricio/patología , Bolsa de Fabricio/fisiología , Cortisona/administración & dosificación , Relación Dosis-Respuesta a Droga , Epitelio/patología , Técnica del Anticuerpo Fluorescente , Inmunoglobulina G/análisis , Inmunoglobulina M/análisis , Inyecciones Intramusculares , Leucocitosis/inducido químicamente , Células Plasmáticas/patología , Receptores de Antígenos de Linfocitos B/análisisRESUMEN
Three weeks following the splenectomy of young chickens an increased number of the hypertrophic epithelial cells, which presented various signs of secretory activity, could be observed in the thymus. After splenectomy, these cells usually present a single, large-sized intracytoplasmic vesicle or vacuole lined with microvilli. The lumen of such vesicles is always full of granulated and membranous material. The ultrastructural appearance of the hypertrophic epithelial cells strongly suggests an intensive metabolic activity and a possible active protein synthesis. These results lead to the hypothesis that hypertrophic epithelial cells secrete a lymphopoietic hormones which is active in normal chickens and which is secreted at an accelerated rate during certain hyperfunctional circumstances such as the period following splenectomy.
Asunto(s)
Esplenectomía , Timo/patología , Animales , Pollos , Gránulos Citoplasmáticos/ultraestructura , Retículo Endoplásmico/ultraestructura , Epitelio/metabolismo , Epitelio/patología , Epitelio/ultraestructura , Femenino , Hipertrofia/patología , Masculino , Mitocondrias/ultraestructura , Timo/metabolismo , Timo/ultraestructuraRESUMEN
The repeated exposure to cold of 2-month- and 2-year-old rats resulted in an important depression of the activity of numerous enzymes in the adrenal cortex. The simultaneous treatment with Aslavital administered in successive doses prevented the decrease of the enzymic activity. It seems that Aslavital exerted a stimulating action on the biosynthesis processes of glucocorticoid hormones and subsequently induced the processes of acclimatization to cold in rats submitted to treatment.