Co-localization of human growth hormone and human prolactin in hormonally pure human growth hormone-producing pituitary adenomas.
Co-localization of human growth hormone (hGH) and human prolactin (hPRL) in hGH-producing pituitary adenomas was examined by electron microscopy with immunoblot analysis. At the electron microscopic level using anti-hGH or anti-hPRL polyclonal antibody, hGH and hPRL were found to be co-localized within each of the secretory granules in one of five cases. Double-labeling electron immunocytochemistry using colloidal gold particles of different sizes was effective in demonstrating this co-localization. As an additional step, we performed immunoblot analysis of hGH-producing pituitary adenomas using monoclonal antibodies. Four hGH-producing adenomatous tissue samples contained several hPRL-immunoreactive bands. In Case 2, the main 23K hPRL band was stained especially strongly The immunoblotting analysis of purified hGH using both anti-hPRL polyclonal antibody and monoclonal antibody to asses cross-reaction of the polyclonal anti-hPRL antisera with hGH revealed that both monoclonal and polyclonal antibodies were suitable for determining the co-localization. Double-labeling techniques using anti-hGH and anti-hPRL monoclonal antibodies demonstrated that only a few secretory granules were positive for co-localization of both hGH and hPRL (Case 2). The present study, which used not only polyclonal but also monoclonal antibodies, suggests that some hGH-producing pituitary adenomas contained both hPRL and hGH in the same secretory granules of tumor cells.
Division of Neurosurgery, Institute of Neurological Sciences, Tottori University School of Medicine, Tokyo.
M
M
Kurosaki
T
T
Watanabe
T
T
Hori
K
K
Hirai
H
H
Kawakami
H
H
Hirano
D000236:Adenoma / Q000473:pathology*; D000328:Adult; D000368:Aged; D003594:Cytoplasmic Granules / Q000473:pathology; D005260:Female; D019382:Human Growth Hormone / Q000032:analysis*; D006801:Humans; D015151:Immunoblotting; D008297:Male; D008854:Microscopy, Electron; D008875:Middle Aged; D010902:Pituitary Gland / Q000473:pathology; D010911:Pituitary Neoplasms / Q000473:pathology*; D011388:Prolactin / Q000032:analysis*
D019382:Human Growth Hormone; D011388:Prolactin