Adjuvant arthritis in the rat is associated with decreased binding of nuclear receptors to thyroid hormone responsive element in spleen extracts

In vertebrates, thyroid hormone and its cognate nuclear receptors are invol ved in a complex arrangement of physiological and developmental function. S ince thyroid hormone has also been shown to affect immune responses, we inv estigated the DNA binding status of T-3 receptors of spleen nuclear extract s 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 re ceptors to DR4 thyroid hormone responsive DNA element was found in the sple ens 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 - thyr oid hormone responsive element complex status within the eel nucleus may be altered in adjuvant arthritis.