Immunocytochemical and in situ hybridization studies of peptidylglycine alpha-amidating monooxygenase in pituitary gland.
The pituitary gland contains high levels of peptidylglycine alpha-amidating monooxygenase (PAM) activity and mRNA. Using affinity-purified rabbit polyclonal antisera generated to synthetic PAM peptides and PAM RNA probes, immunocytochemical and in situ hybridization studies were conducted to determine the tissue disposition and cell types expressing PAM in the adult male rat pituitary gland. PAM immunoreactivity was present at varying levels in nearly all of the anterior pituitary cells; one cell population stained intensely, while others stained moderately or weakly. These results correlated well with in situ hybridization studies that demonstrated high levels of PAM mRNA in a subpopulation comprising approximately 10-15% of the anterior pituitary cells. Based upon immunocytochemistry, intermediate pituitary lobe cells were divided into an intensely stained and a moderately stained group. PAM staining was also present in neural lobe fibers. Immunocytochemical staining of serial pituitary tissue sections for PAM and other pituitary hormones demonstrated that the anterior pituitary cells intensely stained for PAM represented a subpopulation of the gonadotropes. PAM was also identified at moderate levels in corticotropes and at lower levels in sommatotropes and lactotropes. These results suggest that many anterior pituitary cells are capable of producing amidated peptides along with their major peptide hormone.
May
V
V
Department of Anatomy and Neurobiology, University of Vermont College of Medicine, Burlington 05405.
Ouafik
L
L
Eipper
B A
BA
Braas
K M
KM
D000324:Adrenocorticotropic Hormone / Q000032:analysis; D000818:Animals; D005640:Follicle Stimulating Hormone / Q000032:analysis; D013006:Growth Hormone / Q000032:analysis; D007150:Immunohistochemistry; D007986:Luteinizing Hormone / Q000032:analysis; D008297:Male; D006899:Mixed Function Oxygenases; D009097:Multienzyme Complexes; D009693:Nucleic Acid Hybridization; D000587:Oxidoreductases Acting on CH-NH Group Donors / Q000032:analysis* / Q000235:genetics; D010902:Pituitary Gland / Q000032:analysis / Q000201:enzymology*; D011388:Prolactin / Q000032:analysis; D015347:RNA Probes; D012333:RNA, Messenger / Q000032:analysis; D051381:Rats; D013972:Thyrotropin / Q000032:analysis; D014018:Tissue Distribution
D009097:Multienzyme Complexes; D015347:RNA Probes; D012333:RNA, Messenger; D000324:Adrenocorticotropic Hormone; D011388:Prolactin; D007986:Luteinizing Hormone; D005640:Follicle Stimulating Hormone; D013972:Thyrotropin; D013006:Growth Hormone; D006899:Mixed Function Oxygenases; C035189:peptidylglycine monooxygenase; D000587:Oxidoreductases Acting on CH-NH Group Donors