Distribution of cystatin C (gamma-trace), an inhibitor of lysosomal cysteine proteinases, in the anterior lobe of simian and human pituitary glands.

Cystatin C, a protein inhibitor of lysosomal cysteine proteinases, was demonstrated by immunohistochemical techniques to be present in most luteinizing hormone- (LH-)containing cells in simian and human adenohypophyses. Immunoreactivity of cystatin C was also found in simian adrenocorticotrophic hormone- (ACTH-)containing cells localized to an area corresponding to the pars intermedia but not in the ACTH-containing cells of the anterior pituitary lobe of monkey. No immunoreactivity of cystatin C was detected in the growth hormone- (GH-) and prolactin-containing cells of monkey and man.