Opiate-induced constipation related to activation of small intestine opioid μ2-receptors

Table 1 Effects of inhibitors of cyclic adenosine monophosphate-phosphodiesterase or protein kinase A on the relaxation

	ACh (%)
Loperamide (10 μmol/L)
+ Vehicle	63.59 ± 5.60
+ H-89 (1 μmol/L)	80.49 ± 3.07a
+ IBMX (10 μmol/L)	41.02 ± 2.57b
+ Glibenclamide (1 μmol/L)	83.52 ± 0.89a
Forskolin (5 μmol/L)
+ Vehicle	31.64 ± 7.39
+ H-89 (1 μmol/L)	79.29 ± 2.76b
+ IBMX (10 μmol/L)	27.77 ± 1.40b
+ Glibenclamide (1 μmol/L)	80.98 ± 2.75b
IBMX (10 μmol/L)	93.41 ± 2.15b
H-89 (1 μmol/L)	91.31 ± 3.47b
Glibenclamide (1 μmol/L)	92.45 ± 3.29b

Effects of inhibitors of cyclic adenosine monophosphate-phosphodiesterase or protein kinase A on the relaxation induced by loperamide (10 μmol/L) or forskolin (5 μmol/L) in isolated ileum contracted with 1 μmol/L acetylcholine (ACh). IBMX: 3-isobutyl-1-methylxanthine.

^aP < 0.05,

^bP < 0.01 vs vehicle treated control.