Effect of rhubarb on contractile response of gallbladder smooth muscle strips isolated from guinea pigs

Table 1 Effect of rhubarb on resting tension (g) of isolated guinea pig gallbladder muscle strips after pretreatment with antagonists (mean±SE).

Resting tension (g)	Rhubarb (g/L)
	0	0.05	0.15	5	15	50	100
Rhubarb	0	0.03±0.01	0.09±0.02c	0.20±0.03c	0.48±0.03c	0.46±0.02c	0.40±0.02c
Phe+Rhu	0	0.04±0.01	0.06±0.01e	0.11±0.01cg	0.33±0.05cg	0.30±0.05cg	0.27±0.04cg
Hex+Rhu	0	0.04±0.01	0.08±0.01e	0.17±0.02g	0.39±0.02g	0.40±0.02g	0.35±0.02g
Atr+Rhu	0	0g	0.03±0.01g	0.07±0.01ag	0.22±0.04cg	0.19±0.03cg	0.16±0.01cg
Iso+Rhu	0	0.03±0.01	0.07±0.01c	0.10±0.01ce	0.30±0.01cg	0.28±0.02cg	0.21±0.02cg

^aP<0.05,

^cP<0.005 vs control (the gallbladder spontaneous contraction under 1-g initial load when rhubarb was 0 g/L) n = 12. The resting tension of each strip in control was 0.

^eP<0.05,

^gP<0.005 vs rhubarb (the resting tension of adding each concentration of rhubarb) n = 12.

Table 2 Effect of rhubarb on the contractile amplitude (mm) of isolated guinea pig gallbladder muscle strips after pretreatment with antagonists (mean±SE).

Amplitude (mm)	Rhubarb (g/L)
	0	0.05	0.15	5	15	50	100
Rhubarb	5.2±0.7	4.9±0.7	5.0±0.7	4.8±0.7	4.0±0.5	3.0±0.4a	2.7±0.4c
Phe+Rhu	3.3±0.4	3.2±0.4	3.1±0.4	3.0±0.4	2.9±0.4	2.3±0.4	1.7±0.4c
Hex+Rhu	4.7±0.6	4.5±0.6	4.3±0.6	4.2±0.6	3.8±0.8	3.1±0.5	2.7±0.5a
Atr+Rhu	5.4±0.9	5.3±0.9	5.1±0.8	4.8±0.7	4.5±0.7	3.8±0.6	3.1±0.5a
Iso+Rhu	5.2±0.9	5.1±1.0	4.9±1.0	4.7±0.8	4.4±0.9	3.4±0.6	3.0±0.5

^aP<0.05,

^cP<0.005 vs control (the gallbladder spontaneous mean contraction amplitude under 1-g initial load when rhubarb was 0 g/L) n = 12.

Table 3 Effect of rhubarb on the contractile frequency (waves/min) of isolated guinea pig gallbladder muscle strip after pretreatment with antagonists (mean±SE).

Frequency (w/min)	Rhubarb (g/L)
	0	0.05	0.15	5	15	50	100
Rhubarb	4.1±0.5	4.0±0.4	4.1±0.5	4.4±0.4	5.0±0.3	6.3±0.5c	6.1±0.4c
Phe+rhu	4.2±0.5	4.5±0.5	4.6±0.6	4.6±0.5	4.8±0.6	5.5±0.6	6.0±0.5c
Hex+rhu	3.7±0.3	3.8±0.4	3.8±0.4	4.1±0.5	4.9±0.6	5.3±0.7c	5.5±0.5c
Atr+rhu	3.5±0.4	3.4±0.4	3.5±0.4	3.7±0.4	4.0±0.4	4.8±0.5c	5.0±0.5c
Iso+rhu	4.1±0.4	4.1±0.4	4.1±0.4	4.2±0.4	4.5±0.4	5.0±0.5	4.9±0.4

^aP<0.05,

^cP<0.005 vs control (the gallbladder spontaneous contraction frequency under 1-g initial load when rhubarb was 0 g/L) n = 12.