title: Down regulated expression of the beta1 subunit of the big-conductance Ca2+ sensitive K+ channel in sphincter of Oddi cells from rabbits fed with a high cholesterol diet.
abstract: Hypercholesterolemia, which is closely related to gallbladder bile stasis, can cause sphincter of Oddi dysfunction (SOD) by increasing the tension of sphincter of Oddi (SO). Intracellular calcium ion concentration ([Ca(2+)](i)) could influence the tension of SO. The beta1 subunit of the big-conductance Ca(2+) sensitive K(+) channel (BK(Ca)) can enhance the sensitivity of the BK(Ca) channel to [Ca(2+)](i). Absence and decline of the BKCa channel subunit beta1 could lead to many diseases. However, the relationship between hypercholesterolemia and the expression of beta1 subunit is not well understood. In this study, we successfully expressed and purified the rabbit BK(Ca) beta1 subunit protein and prepared its polyclonal antibody. The specificity of the prepared antibody was determined by Western blotting. A SOD rabbit model induced by a high cholesterol diet was established and the expression of the beta1 subunit of SO was determined by immunohistochemical staining and western blotting. Compared with the controls, our results demonstrated that hypercholesterolemia could decrease the expression of the beta1 subunit in the SO cells from rabbits. This indicates that lower expression of BKCa channel beta1 subunit might induce SOD.
authors.affiliation: Department of Radiology, Tangdu Hospital, Fourth Military Medical University, Xi'an 710038, China.
authors.forename: Pang
authors.initials: P
authors.lastname: Du
authors.forename: Guang-Bin
authors.initials: GB
authors.lastname: Cui
authors.forename: Ya-Rong
authors.initials: YR
authors.lastname: Wang
authors.forename: Xiao-Yong
authors.initials: XY
authors.lastname: Zhang
authors.forename: Ke-Jun
authors.initials: KJ
authors.lastname: Ma
authors.forename: Jing-Guo
authors.initials: JG
authors.lastname: Wei
mesh_terms: D000818:Animals; D002118:Calcium / Q000737:chemistry*; D002784:Cholesterol / Q000097:blood / Q000378:metabolism*; D015536:Down-Regulation; D005260:Female; D005786:Gene Expression Regulation; D005982:Glutathione Transferase / Q000378:metabolism; D006937:Hypercholesterolemia / Q000378:metabolism*; D007150:Immunohistochemistry; D051038:Large-Conductance Calcium-Activated Potassium Channel beta Subunits / Q000737:chemistry* / Q000378:metabolism; D051379:Mice; D008807:Mice, Inbred BALB C; D011817:Rabbits; D011993:Recombinant Fusion Proteins / Q000737:chemistry
chemical_list: D051038:Large-Conductance Calcium-Activated Potassium Channel beta Subunits; D011993:Recombinant Fusion Proteins; D002784:Cholesterol; D005982:Glutathione Transferase; D002118:Calcium