| Background and objective:Sphincter of Oddi is located the position where the bile duct go into the duodenum. It is a important anatomic structure and it play an key role in regulating biliary and pancreatic flow and preventing back flow from duodenum to ductal system. The sphincter of Oddi dysfunction may be one dynamics cause for biliary tract diseases, pancreatic diseases and gastrointestinal diseases.Our serial research indicated that the motivation of SO had a abnomal change under the hypercholesterolemia. In habbits the hypercholesterolemia can lead to the damage of the normal contractility and ultrastructure abnormalities. These changes above were correlated with [Ca2+]i overload of SO cell. Ca2+ is a key facter of excitation-contraction. And it is a material foundation on which calcium signal is generated andtransmit. In some research it was revealed that calcium oscillation was related with the constraction in the smooth muscle. But now few data has been reported about this relation between calcium metabolic disorder and calcium signal.In this study, cells dispersion, culture and laser scanning confocal microscopy were performed to study the effect of hypercholesterolemia on Character of calcium oscillation of Oddi's sphincter muscle cells in rabbits, in order to further explore the relationship between the mechanisms of Oddi's sphincter dysfunction and the changes of Ca2+ signal.by hypercholester -olemia.Materials and Methods:Thirty-two New Zealand female rabbits were divided randomly into two groups: the control group and the hypercholesterolemia group. The rabbits in the control group were fed with normal diet, while the rabbits in the hypercholesterolemia group were fed with hypercholesterol diet. Both groups were fed for 8 weeks. And then the fllowing empirical studies were performed.* Sphincter of Oddi's muscle dissociated from Two group rabbits, primarily cultured respectively, loaded with Fluo-3/AM. By using Laser scanning confocal microscopy, changes in the character of calcium oscillation on the smooth muscle cells of SO were measured under the quiescent condition and the action of nifedipine, Thapsigargin.* Evaluate calcium pump activity of two groups rabbit by mensuration of phosphonium.* Compare express status of IP3 receptor between two groups rabbits byimmunofiuorescence technique.Results:* In the hypercholesteremia group, the fluorescence intensity oscillation amplitude of SO cells in quiescent condition is 6.11 ±3.1, and the size of oscillation amplitude is not conformity. And its frequence is 9 ±2.1 /min, the calcium foundational fluorescence intensity was 44.3 ± 2.05; however, in the control group the amplitude is 3.61 ± 0.94, its frequence is 6 + 2 /min. the amplitude and frequence of the hypercholesteremia group is more higher than that of the control group. (P<0.05).* After being applied nifedipine and EDTA ,in the hypercholesteremia group, the calcium fluorescence intensity oscillation amplitude of SO cells diminished from 6.11 ±3.1 to 2.24±0.72, decreased 64%,and the frequency of calcium oscillation diminished from9±2.1min"1 to 6+1.3 min"1, the calcium foundational fluorescence intensity descend under 35; in the control group the calcium foundational fluorescence intensity decreaced under 30, calcium oscillation almost disappear.* After being applied thapsigarign, in the hypercholesteremia group, the calcium fluorescence'intensity oscillation amplitude diminished to 3.8 ± 1.9, decreased 38%. But in the control group the calcium fluorescence intensity oscillation amplitude had not changed.* The change of calcium oscillation physics character was positive correlation with the foundational calcium concentration, in SO cell.* The calcium pump activity in hypercholesteremia group was 30.23 ±... |
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