Effects of mu and kappa opioid receptor agonists and antagonists on contraction of isolated colon strips of rats with cathartic colon

Table 1 Effect of Damgo on electricity-stimulated contractile response of cathartic colon strips (mean ± SD)

Concentration (µmol/L)	Basic contraction amplitude without Dampo (mm)	Contraction amplitude with Dampo (mm)
0.05	11.40 ± 0.21	8.50 ± 0.89b
0.10	11.40 ± 0.21	6.24 ± 0.91ab
1.00	11.40 ± 0.21	3.35 ± 0.64bd

^aP < 0.05 vs 0.05 µmol/L,

^bP < 0.01 vs without Dampo,

^dP < 0.01 vs 0.05 µmol/L.

Table 2 Effect of naloxone on electricity-stimulated contrac-tile response of cathartic colon strips (mean ± SD)

Concentration (µmoL)	Basic contraction amplitude without naloxone (mm)	Contraction amplitude with naloxone (mm)
0.05	11.40 ± 0.21	13.18 ± 0.93b
0.10	11.40 ± 0.21	15.87 ± 0.98ab
1.00	11.40 ± 0.21	19.46 ± 1.79bd

^aP < 0.05 vs 0.05 µmol/L,

^bP < 0.01 vs without Naloxone,

^dP < 0.01 vs 0.05 µmol/L.

Table 3 Effects of U50488H on electricity-stimulated contrac-tile response of cathartic colon strips (mean ± SD)

Concentration (µmol/L)	Basic contraction amplitude before administration (mm)	Contraction amplitude after administration (mm)
0.05	11.40 ± 0.21	8.98 ± 0.69b
0.10	11.40 ± 0.21	6.89 ± 0.71ab
1.00	11.40 ± 0.21	4.43 ± 0.99bd

^aP < 0.05 vs 0.05 µmol/L,

^bP < 0.01 vs before administration,

^dP < 0.01 vs 0.05 µmol/L.