AIM:The rote of the sphincter of Oddi(SO)in ethanol(ETOH)-induced pancreatitis is controversial.Our aim wasto characterise the effect of E-I-OH on basal and stimulatedSO motility.METHODS:SOs removed from white rabbits were placedin an organ bath(Krebs solution,pH7.4,37℃).The effectsof 2 mL/L,4 mL/L,6 mL/L and 8 mL/L of ETOH on thecontractile responses of the sphincter were determined.SOs were stimulated with either 0.1 μmol/L carbachol,1μmol/L erythromycin or 0.1 μmol/L cholecystokinin(CCK).RESULTS:ETOH at a dose of 4 mL/L significantly decreasedthe baseline contractile amplitude from 11.98±0.05 mN to11.19±0.07 mN.However,no significant changes in thecontractile frequency were observed.ETOH(0.6%)significantly decreased both the baseline amplitude and thefrequency compared to the control group(10.50±0.01 mN,12.13±0.10 mN and 3.53±0.13 c/min,5.5±0.13 cycles(c)/min,respectively).Moreover,0.8% of ETOH resulted in completerelaxation of the SO.Carbachol(0.1 μmol/L)or erythromycin(1 μmol/L)stimulated the baseline amplitudes(by 82%and 75%,respectively)and the contractile frequencies(by 150% and 106%,respectively).In the carbachol orerythromydn-stimulated groups 2-6 mL/L of E-IOH significantlyinhibited both the amplitude and the frequency.Interestingly,a 4-5 min administration of 6 mL/L ETOH suddenly andcompletely relaxed the SO.CCK(0.1 μmol/L)stimulatedthe baseline amplitude from 12.37±0.05 mN to 27.40±1.82mN within 1.60±0.24 min.After this peak,the amplitudedecreased to 17.17±0.22 mN and remained constant duringthe experiment.The frequency peaked at 12.8±0.2 c/min,after which the constant frequency was 9.43±0.24 c/minthroughout the rest of the experiment.ETOH at a doseof 4 mL/L significantly decreased the amplitude from16.13±0.23 mN to 14.93±0.19 mN.However,no significantchanges in the contractile frequency were observed.ETOHat a dose of 6 mL/L inhibited both the amplitudes and thefrequencies in the CCK-stimulated group,while 8 mL/L ofETOH completely relaxed the SO.CONCLUSION:ETOH strongly inhibits the basal,carbachol,erythromycin,and CCK-stimulated rabbit SO motility.Therefore,it is possible that during alcohol-intake the relaxed SO opens the way for pancreatic fluid to flow outinto the duodenum in rabbits.This relaxation of the SOmay protect the pancreas against alcohol-induced damage. AIM: The rote of the sphincter of Oddi (SO) in ethanol (ETOH) -induced pancreatitis is controversialial. Our aim wasto characterise the effect of EI-OH on basal and stimulatedSO motility. METHODS: SOs removed from white rabbits were placedin an organ The effects of 2 mL / L, 4 mL / L, 6 mL / L and 8 mL / L of ETOH on thecontractile responses of the sphincter were determined.SOs were stimulated with either 0.1 mmol / L carbachol, 1 μmol / L erythromycin or 0.1 μmol / L cholecystokinin (CCK) .RESULTS: ETOH at a dose of 4 mL / L significantly decreased the baseline contractile amplitude from 11.98 ± 0.05 mN to 11.19 ± 0.07 mN.However, no significant changes in the contractile frequency were observed. ETOH (0.6%) significantly decreased both baseline amplitude and the frequency compared to the control group (10.50 ± 0.01 mN, 12.13 ± 0.10 mN and 3.53 ± 0.13 c / min, 5.5 ± 0.13 cycles ( c) / min, respectively). Moreover, 0.8% of ETOH resulted in complete relaxation of the SO.Carbachol (0.1 μmol / L) or erythromycin Stimulated the baseline amplitudes (by 82% and 75%, respectively) and the contractile frequencies (by 150% and 106%, respectively) .In the carbachol orerythromydn-stimulated groups 2-6 mL / L of E -IOH significantly inhibited by the 4-5 min administration of 6 mL / L ETOH suddenly and completely relaxed by SO.CCK (0.1 μmol / L) stimulated the baseline amplitude from 12.37 ± 0.05 mN to 27.40 ± 1.82 mN within 1.60 ± 0.24 min. After this peak, the amplitude was established to 17.17 ± 0.22 mN and remained constant during the experiment. The frequency peaked at 12.8 ± 0.2 c / min, after which the constant frequency was 9.43 ± 0.24 c / minthroughout the rest of the experiment.ETOH at a dose of 4 mL / L significantly decreased the amplitude from 16.13 ± 0.23 mN to 14.93 ± 0.19 mN.However, no significant changes in the contractile frequency were observed. ETOHat a dose of 6 mL / L inhibited both the amplitudes and thefrequencies in the CCK-stimulated group, while 8 mL / L of EtOH completely relaxed the SO.CONCLUSION: ETOH strongly inhibits the basal, carbachol, erythromycin, and CCK-stimulated rabbit SO motility. Before it, it is possible that during alcohol-intake the relaxed SO opens the way for pancreatic fluid to flow outinto the duodenum in rabbits. This relaxation of the SOmay protect the pancreas against alcohol-induced damage.