Effect Of Ethanol On Sphincter Of Oddi Motility In Conscious Rats

Objective Alcohol is one of the factors which induces pancreatitis, this study was to observe whether ethanol would affect sphincter of oddi(SO) motility Methods Amanometric catheter for measuring SO pressure and a silastic cannula for drugs were aseptically implanted into the common bile duct and the mid-duodenum respectively in each of 10 rats . experiment began 7 days after recovery form operation . the changes of SO pressure was recorded in both ethanol group and control group. Using low compliance capillary water perfusion system, various doses of ethanol(50ml/l, 150ml/l, 300ml/l)each were infused intra duodenally(id) or intra venously(iv) within 30 minutes at a rate of 0.25ml/min in two-three seperate days. Normal saline was given instead of ethanol in control group. Results (1)Basalpressure of SO was 1.71 0.33kpa in id 150ml/l ethanol group and 1. 13 0. 17kpa in id 300ml/l ethanol group. Both decreased significantly as compared with that in control 2.32 0. 57kpa(P<0. 05, P<0. 01). Amplitudes and frequences of phastic contraction in both groups were 5. 64 1. 94kpa and 3. 68 1. 51kpa, 2. 8 1. 1times/min and 1.9 0.7times/min. All these parameters were lower than those in saline control groups (Amplitude and frequency were 7. 68 2. 45kpa and 3. 6 0. 8times/min respectively, P<0. 05). (2) Basal pressure of SO was 1.56 0.28kpa in iv 150ml/l ethanol group, and 1.09 0. 21kpa in iv 300ml/l ethanol group,both decreased as compared to control group (P<0. 05, P<0. 01). Amplitude and frequency were 6. 34 2.20kpa and 2.7 1. Otimes/min, and in iv 300ml/lethanol group were lower than those in control group (P<0. 05, P<0. 01) (3) Durations of contractions of SO in id 150ml/l or 300ml/l ethanol group were 7.4 2. 1s and 8.3 2.5s, and in iv 150ml/l or 300ml/lethanol group were 7.2 2. 3s and 8. 6 2. 7s, respectively. All were longer as compared to saline control (P<0. 01). (4) No difference of alterations of SO motility was found between the two ways of intraduodenal and intravenous infusion of ethanol. Conclusion Ethanol inhibits SO motility with resulting reflux of duodenal contents into the biliary and pancreatic ductal system, and this may play an important role in alcohol-induced pancreatitis, considering the fact that intravenous ethanol infusion affected SO motility like intraduodenal infusion of ethanol, it suggest that alcohol, which is absorbed into blood throughintestinal mucosa after drinking, continues to disturb SO motility.