Comparative Relaxant Effects of Ataciguat and Zaprinast on Sheep Sphincter of Oddi.
BACKGROUND
Relaxing the sphincter of Oddi (SO) is an important process during endoscopic retrograde cholangiopancreatography (ERCP) procedures. This issue suggests that the easier the sphincterotomy and cannulation, the more post-ERCP complications decrease.


OBJECTIVE
To compare the relaxant effects of ataciguat (a novel soluble guanylyl cyclase activator) and zaprinast (an inhibitor of phosphodiesterase 5) on sheep SO in vitro, thus testing whether they can be used during ERCP.


METHODS
Animal experimentation.


METHODS
Sheep SO rings were placed in tissue baths and their isometric tension to ataciguat and zaprinast were tested. We also tested their isometric tension against ataciguat in the presence of 1H-(1,2,4) oxadiazole (4,3-a) quinoxalin-1-one (ODQ) which is a soluble guanylyl cyclase inhibitor.


RESULTS
Ataciguat and zaprinast both triggered concentration addicted relaxation on sheep SO rings (p=0.0018, p=0.0025 respectively) but the relaxation of the ataciguat was significantly greater than that of zaprinast at all concentrations (p=0.0024). It was observed that decreased relaxation responses were initiated by ataciguat in the presence of ODQ (p=0.0012).


CONCLUSIONS
Ataciguat and zaprinast both have relaxing effects on sphincter of Oddi, although that of zaprinast is lower. We believe that ataciguat and zaprinast can be used in ERCP procedures in order to relax the sphincter of Oddi and thus can be used locally in order to decrease complications.
Department of Gastroenterology, Cumhuriyet University School of Medicine, Sivas, Turkey.
Erol
E
Çakmak
Department of Gastroenterology, Cumhuriyet University School of Medicine, Sivas, Turkey.
Özlem
Ö
Yönem
Department of Pharmacology, Cumhuriyet University School of Medicine, Sivas, Turkey.
Bülent
B
Saraç
Department of Pharmacology, Sivas Numune Hospital, Sivas, Turkey.
Mesut
M
Parlak
Department of Internal Medicine, Sivas Numune Hospital, Sivas, Turkey.
Cumali
C
Çelik
Department of Gastroenterology, Sivas Numune Hospital, Sivas, Turkey.
Hilmi
H
Ataseven
Department of Pharmacology, Cumhuriyet University School of Medicine, Sivas, Turkey.
İhsan
İ
Bağcivan
Ataciguat; Oddi’s sphincter; zaprinast