Xestospongin C-sensitive calcium stores and angiotensin II-induced myometrial contraction

作者：Tica Oana Sorina^*; Tica A A; Dun Erika; Tica V I; Berceanu C; Braila Anca

来源：Gineco.ro, 2010, 6(1): 34-36.

• endoplasmic reticulum calcium stores
• IP3
• myometrium
• angiotensin II
• xestospongine C

Objective: The role of inositol 1,4,5 triphosphate (IP3)-sensitive calcium stores on angiotensin II (AG II)-induced uterine contraction was studied by blocking IP3 receptors with xestospongin C (Xe C). This is for the first time when Xe C is used to evaluate the implication of IP3-sensible intracellular calcium stores, during AG II-induced uterine contraction. Study design: We worked on non pregnant rat uterine strips, comparing contractions to AG II 10-7 M, before and after Xe C 10-7 M administration. Results: Xe C decreased the AG II-induced contraction with 34.12 +/- 11%, the amplitude being more inhibited than the frequency, which was decreased with 18.75 +/- 5%. Meantime, Xe C reduced also the amplitude of the automatic oscillations with 38.79 +/- 8%, but their frequency was not affected. Conclusions: IP3-sensitive calcium stores have a stronger role on force than on frequency of oscillations during AG II-induced contraction. In basal conditions, these calcium stores are partially responsible for the amplitude of automatic uterine contractions, with no impact on spontaneous depolarizing, since frequency is not decreased by Xe C.

• 出版日期2010