Distribution of thyrostimulin in the rat: an immunohistochemical study.

Objective: 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.

Method: 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.

Results: 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.

Conclusion: These findings suggest that thyrostimulin is widely distributed and that the method used is valuable in studying the distribution of thyrostimulin in rats.