Discrepancy between PNMT presence and relative lack of adrenaline production in extra-adrenal pheochromocytoma.
Among catecholamine synthesizing enzymes, phenylethanolamine-N-methyltransferase (PNMT) exists only in adrenal and extra-adrenal pheochromocytoma has been believed not to produce adrenaline. However, adrenaline production is clinically active in some extra-adrenal cases. To investigate this controversy, the localization of catecholamine synthesizing enzymes was studied by immunohistochemical staining in extra-adrenal and adrenal cases. The results showed that PNMT was expressed not only in many cases of adrenal pheochromocytoma, but also in extra-adrenal pheochromocytoma. It is suspected that little adrenaline production in extra-adrenal cases is attributable to a lack of a good environment for the activation of PNMT by a high concentration of glucocorticoids.
Funahashi
H
H
Department of Surgery II, Nagoya University School of Medicine, Japan.
Imai
T
T
Tanaka
Y
Y
Tobinaga
J
J
Wada
M
M
Matsuyama
T
T
Tsukamura
K
K
Yamada
F
F
Takagi
H
H
Narita
T
T
D000310:Adrenal Gland Neoplasms / Q000201:enzymology; D000328:Adult; D004299:Dopamine beta-Hydroxylase / Q000032:analysis; D004837:Epinephrine / Q000096:biosynthesis*; D005260:Female; D006801:Humans; D007124:Immunoenzyme Techniques; D008297:Male; D008875:Middle Aged; D010625:Phenylethanolamine N-Methyltransferase / Q000032:analysis*; D010673:Pheochromocytoma / Q000201:enzymology*; D014446:Tyrosine 3-Monooxygenase / Q000032:analysis
D014446:Tyrosine 3-Monooxygenase; D004299:Dopamine beta-Hydroxylase; D010625:Phenylethanolamine N-Methyltransferase; D004837:Epinephrine