IMMUNOHISTOCHEMICAL LOCALIZATION OF INTRACELLULAR PROGESTERONE AND GLUCOCORTICOID RECEPTORS IN THE RABBIT LUNG

We have determined the presence and distribution of intracellular prog esterone receptors (PRs) and glucocorticoid receptors (GRs) in the lun g of adult female rabbits using immunohistochemistry. The effects of o variectomy and administration of oestradiol benzoate (10 mu g for 3 co nsecutive days) upon PR and GR immunoreactivity were also studied. The results demonstrated the presence of both steroid hormone receptors i n the female rabbit lung. PR and GR immunoreactivity was predominantly nuclear and located in alveolar epithelial cells and various intersti tial cells such as polymorphonuclear leucocytes. Tissue distribution o f both receptors was similar in all cases. Oestradiol treatment induce d a marked increase in the number of PR immunoreactive cells compared with intact and ovariectomized female animals. Neither ovariectomy nor oestradiol treatment modified the number of GR immunoreactive cells. The presence and localization of intracellular PRs and GRs in several lung cell types suggest that they may play an important role in mediat ing the effects of progesterone and glucocorticoids in various physiol ogical processes in the rabbit lung. The data alsb indicated an oestro gen regulation of PRs in the rabbit lung.