Distribution of thyrostimulin in the rat: an immunohistochemical study.

To identify the distribution of thyrostimulin, a heterodimer of glycoprotein hormone subunits (A2 and B5) by immunohistochemistry in the rat tissues using specific antipeptide anti-serum which we recently produced.Anti-thyrostimulin antibody was raised in New Zealand white rabbits immunized with a conjugate of synthetic A2 or B5 with bovine serum albumin. Immunohistochemical analysis was performed by avidin-biotin complex method.Thyrostimulin immunoreactivity was visualized in the anterior pituitary, central nervous system, adrenal gland, stomach, duodenum, pancreas and testis. When using antiserum pre-incubated with synthetic peptides or rat pituitary homogenate which contains thyrostimulin peptide, no significant stain of the pituitary was detected.These findings suggest that thyrostimulin is widely distributed and that the method used is valuable in studying the distribution of thyrostimulin in rats.