In vertebrates, thyroid hormone and its cognate nuclear receptors are involved in a complex arrangement of physiological and developmental function. Since thyroid hormone has also been shown to affect immune responses, we investigated the DNA binding status of T-3 receptors of spleen nuclear extracts in a) rats with adjuvant arthritis (AA); b) adrenalectomized rats (ADX), and c) animals with adjuvant arthritis followed by adrenalectomy (AA+ADX).
A marked diminution in the functional binding of nuclear thyroid hormone receptors to DR4 thyroid hormone responsive DNA element was found in the spleens of AA and AA+ADX rats when compared to a control group or ADX rats. The data based on in vivo experiments suggest that the nuclear receptor - thyroid hormone responsive element complex status within the eel nucleus may be altered in adjuvant arthritis.