Thyroid Hormone Regulates Tachykinin Gene Expression in Rat Anterior Pituitary

Substance P (SP) and Substance K (SK, also known as neurokinin alpha) are two mammalian tachykinin peptides which are widely but selectively distributed throughout the central and peripheral nervous systems (1). These peptides are also found in endocrine tissues, in particular, in the anterior pituitary gland and their content within this gland can be regulated by thyroid hormone status (2,3). The present studies were performed to determine if the preprotachykinin (PPT) gene which encodes both SP and SK (4) is expressed within the anterior pituitary gland of adult male rats and if so, whether PPT messenger RNA. (mRNA) abundance can be regulated by thyroid hormone status.