Relationship between calcium metabolism and calcium oscillation of Oddi's sphincter in hypercholesterolemic rabbits

AIM: To investigate the effect of hypercholesterolemia on calcium oscillation of acutely separated rabbit Oddi’s sphincter muscle cells and to explore its mechanisms. METHODS: Twenty-four New Zealand female rabbits were divided randomly into control group and HC group (12 rabbits each). Sphincter of Oddi’s muscle cells were acutely isolated and cultured. The cells were loaded with Fluo-3/ AM, and the changes in calcium oscillation were measured by laser scanning confocal microscopy. RESULTS: Compared with the control group, the amplitude of the Ca oscillation fluorescence intensity was significantly increased in the experimental group (6.11±3.1 vs 3.61±0.94, P<0.05). When treated with nifedipine and EDTA, Ca oscillation amplitude in hypercholesterolemic group was decreased by 64% to 2.24±0.72.When treated with thapsigargin, it was decreased by 38% to 3.8±1.9. CONCLUSION: Calcium metabolic disturbance in Oddi’s sphincter muscle cells of hypercholesterolemic rabbits may be caused by the malfunctioned CICR pathway of Ltype voltage-dependent calcium channels.