Tissue specific levels of glucocorticoid receptor within the rat inner ear.

Individual, rat inner ear tissues were isolated and processed for determination of levels of glucocorticoid (GR) receptor by an Enzyme Linked Immuno-Sorbant Assay (ELISA). Differing levels of GR receptor between seven sampled inner ear regions were measured. Levels of GR receptors in the spiral ligament tissues were found to be significantly higher compared to all other tissue samples. GR levels in the tissues of stria vascularis and organ of Corti were different from one another but both were statistically higher than those detected in the vestibular tissue samples (dark cell regions, cristae ampullares and maculae utriculi), which had the lowest GR receptor levels measured. Intermediate levels of GR receptor were found in the endolymphatic sac region. It is suggested that the varying levels of inner ear GR receptors may be indicative of differing biological responses among the given tissues, as well as differences in the magnitudes of such responses to circulating glucocorticoids.