ABSTRACT
Astrocytes participate in central nervous system injury, degenerative diseases and also perform macrophagic functions. The present work investigates: 1) the effect of the physiological glucocorticoid corticosterone (CORT) and the synthetic agonist dexamethasone (DEX) on latex beads phagocytosis by neonatal rat cortical astrocytes in culture, and 2) the expression of immunoreactive glucocorticoid receptors (GR) in astrocytes cultured in different media with or without a pulse application of CORT. The results indicated that glucocorticoids reduced astrocyte phagocytic activity, as occurred with macrophages, independently of the culturing conditions employed. The extent of phagocytosis was inversely related to nuclear immunostaining for GR in cultures in fetal calf serum, which contained endogenous glucocorticoid. However, no correlation was found between nuclear GR and phagocytosis for cultures in glucocorticoid-free medium or in medium containing CORT. It is suggested that additional factors, besides the GR, may be involved in glucocorticoid modulation of astrocyte phagocytosis.
Subject(s)
Animals , Rats , Anti-Inflammatory Agents , Astrocytes , Corticosterone , Dexamethasone , Glucocorticoids , Phagocytosis , Astrocytes , Cells, Cultured , Cerebral Cortex/cytology , Phagocytosis , Rats, Sprague-Dawley , Receptors, GlucocorticoidABSTRACT
El presente trabajo de investigación, presentado con el título completo de "Correlación entre receptores para glucocorticoides y concentración de corticosterona en regiones cerebrales: Sus implicancias para el estudio del estrés", fue desarrollado por las Dras. Ana María Magariños y Mónica Ferrini y el Dr. Alejandro F. de Nicola en el Laboratorio de Bioquímica Neuroendócrina del Instituto de Biológia y Medicina Experimental, cocn el apoyo de la Fundación Raquel Guedikian de Estudios sobre el Estrés. En él se analiza la concentración de corticosterona (CORT) en varias regiones cerebrales de rata y su correlación con el contenido de receptores para glucocorticoides (GC). Los resultados son importantes para localizar los sitios de acción hormonal en el cerebro durante los estados de hiperfunción adrenal, típico del estrés