Adiponectin and adiponectin receptors in human pheochromocytoma.
OBJECTIVE
Recent studies have demonstrated that serum adiponectin and its receptors in adipose and muscle tissues are suppressed in diabetic or obese individuals. Patients with pheochromocytoma are frequently diabetic.


METHODS
Using real-time PCR, we examined mRNA expressions of adiponectin (Adp) and adiponectin receptor 1 (AdpR1) and AdpR2 in pheochromocytoma tissues from 49 patients. We also measured levels of serum total and high molecular weight (HMW) adiponectin levels in 10 pheochromocytomas and 33 normal volunteers.


RESULTS
In pheochromocytoma tissue, AdpR1 mRNA expression was higher in adrenaline (A)-type tumors than in noradrenaline (NA)-type tumors. AdpR1 expression was significantly higher in A-type non-diabetics than in NA-type non-diabetics (p<0.05). AdpR1 mRNA expression was significantly associated with the tumor tissue adrenaline content (p<0.005) in linear regression analysis, which suggest that adrenaline positively regulates AdpR1 mRNA expression.Serum total and HMW Adp levels in patients with NA-type pheochromocytomas were approximately 3 times higher than those of healthy volunteers. After adrenalectomy, levels of adiponectin normalized.


CONCLUSIONS
Our results indicate that serum total and HMW Adp, and AdpR1 gene expressions in pheochromocytoma tissue, are associated with the level of catecholamine produced in the tumor. It is tempting to speculate that catecholamine induces adiponectin production and signaling.
Isobe
Kazumasa
K
Institute of Clinical Medicine, University of Tsukuba, Ibaraki, Japan. k-isobe@md.tsukuba.ac.jp
Fu
Ling
L
Tatsuno
Ichirou
I
Takahashi
Hideto
H
Nissato
Sumiko
S
Hara
Hisato
H
Yashiro
Toru
T
Suzukawa
Kazumi
K
Takekoshi
Kazuhiro
K
Shimano
Hitoshi
H
Kawakami
Yasushi
Y
D052242:Adiponectin / Q000235:genetics*; D000310:Adrenal Gland Neoplasms / Q000737:chemistry*; D000328:Adult; D016022:Case-Control Studies; D002395:Catecholamines / Q000032:analysis / Q000096:biosynthesis; D004837:Epinephrine / Q000032:analysis; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D008970:Molecular Weight; D010673:Pheochromocytoma / Q000737:chemistry*; D012333:RNA, Messenger / Q000032:analysis; D054419:Receptors, Adiponectin / Q000235:genetics*
C475418:ADIPOR1 protein, human; C475420:ADIPOR2 protein, human; D052242:Adiponectin; D002395:Catecholamines; D012333:RNA, Messenger; D054419:Receptors, Adiponectin; D004837:Epinephrine