Activation of adenosine A1-receptor pathway induces edema formation in the pancreas of rats.
OBJECTIVE
Adenosine has been shown to modulate various pathophysiologic conditions through receptor-mediated mechanisms. However, the role of adenosine in the pathogenesis of acute pancreatitis has not been described. We examined the effect of adenosine-receptor stimulation or inhibition on the pathologic changes of the pancreas.


METHODS
Rats received intraperitoneal injections of selective agonists of A1, A2a, and A3 adenosine receptors: 2-chloro-N(6)-cyclopentyladenosine (CCPA), CGS-21680 (CGS), or 1-deoxy-1-[6-[[(3-iodophenyl)methyl]amino]-9H-purin-9-yl]-N-methyl-be ta-D-ribofuranuronamide (IB-MECA), respectively. Serum amylase activity and pathologic changes of the pancreas were evaluated. The effects of a specific A1-receptor antagonist (FK-838) on the pathologic findings of cerulein- and taurocholate-induced pancreatitis were also examined.


RESULTS
Administration of a selective A1 agonist induced hyperamylasemia and morphologic changes in the pancreas characterized by interstitial edema and leukocyte infiltration; neither A2a nor A3 agonist produced such changes. Treatment with an A1-receptor antagonist significantly attenuated the outcome induced by A1 agonist stimulation. In addition, the A1-receptor antagonist significantly ameliorated pancreatic edema in both pancreatitis models, although it did not improve the acinar cell damage of the pancreas or the increase of serum amylase.


CONCLUSIONS
Activation of the adenosine A1-receptor pathway may have an important role in the pathogenesis of acute pancreatitis.
Satoh
A
A
Third Department of Internal Medicine, Tohoku University School of Medicine, Sendai, Miyagi, Japan. asato@int3.med.tohoku.ac.jp
Shimosegawa
T
T
Satoh
K
K
Ito
H
H
Kohno
Y
Y
Masamune
A
A
Fujita
M
M
Toyota
T
T
D000208:Acute Disease; D000241:Adenosine / Q000031:analogs & derivatives* / Q000494:pharmacology; D000681:Amylases / Q000097:blood; D000818:Animals; D002108:Ceruletide; D004487:Edema / Q000209:etiology* / Q000473:pathology; D007962:Leukocytes / Q000473:pathology; D008297:Male; D010179:Pancreas / Q000473:pathology; D010182:Pancreatic Diseases / Q000209:etiology* / Q000473:pathology; D010195:Pancreatitis / Q000139:chemically induced / Q000473:pathology; D010627:Phenethylamines / Q000494:pharmacology; D058906:Purinergic P1 Receptor Agonists; D058915:Purinergic P1 Receptor Antagonists; D011720:Pyrazoles / Q000494:pharmacology; D011725:Pyridines / Q000494:pharmacology; D051381:Rats; D017208:Rats, Wistar; D043684:Receptor, Adenosine A3; D018047:Receptors, Purinergic P1 / Q000502:physiology*; D013656:Taurocholic Acid
D010627:Phenethylamines; D058906:Purinergic P1 Receptor Agonists; D058915:Purinergic P1 Receptor Antagonists; D011720:Pyrazoles; D011725:Pyridines; D043684:Receptor, Adenosine A3; D018047:Receptors, Purinergic P1; C061282:2-(4-(2-carboxyethyl)phenethylamino)-5'-N-ethylcarboxamidoadenosine; C102861:FK 838; C084956:N(6)-(3-iodobenzyl)-5'-N-methylcarboxamidoadenosine; C058394:2-chloro-N(6)cyclopentyladenosine; D013656:Taurocholic Acid; D002108:Ceruletide; D000681:Amylases; D000241:Adenosine