A critique of the contributions of immunoperoxidase cytochemistry to our understanding of pituitary cell function, as illustrated by our current studies of gonadotropes, corticotropes and endogenous pituitary GnRH and TRH. 
The peroxidase-antiperoxidase technique has been used to study sites of pituitary hormone storage and binding.  Some recent findings from our laboratory show that the technique can make intriguing contributions to our understanding of pituitary cell function.  In serial, ultra-thin sections, one can identify two or three hormones in a given cell.  During pre-pubertal development, gonadotropes may contain adrenocorticotropin immunoreactivity.  Brain releasing hormones may be stored or sequestered in granules of cells they stimulate.  This report includes a discussion and critique of our recent findings and interpretations which must be considered before one draws any conclusions about their biological significance.