Abstract
Using rabbits, this study was undertaken to ascertain whether various physical conditions of the host, as well as pretreatment with prednisolone, affect the glucocorticoid receptor (GR) content of the bronchoalveolar lavage (BAL) cells. Our results have shown that BAL-cells from rabbits of various ages were found to exhibit an age-dependent reduction of the GR content. As for the effect of nutritional deprivation, the GR content tended to increase during the initial phase of malnutrition (days 4 to 8), and then return to the control level after day 12. Most significantly, the GR content of the BAL-cells from malnourished rabbits showed a limited response to cellular activation. Further, chronological changes were seen in the GR content of BAL-cells from non-treated rabbits and from sensitized rabbits that were given an intravenous injection of prednisolone (2mg/kg). In both instances, the GR content showed a transitory decrease after 3 hours, and a rapid increase by day 4, followed by a return to the control levels. In contrast, no significant changes in the dissociation constant were seen among the BAL-cells from each experimental procedure. These results indicate that the GR content of BAL-cells are greatly influenced by the conditions of the host, such as aging, cellular activation from a sensitization, malnutrition, and pretreatment with a steroid, so that these factors should be considered before deciding on a regimen of steroid therapy.
