Chen Q, Amaral J, Oh S, Biancani P, Behar J
Department of Medicine, Rhode Island Hospital, Providence, USA.
Gastroenterology. 1997 Sep;113(3):930-7. doi: 10.1016/s0016-5085(97)70189-6.
BACKGROUND & AIMS: Gallbladders with cholesterol stones show a defective contraction in response to agonists. The aim of this study was to investigate the muscle relaxation of human gallbladders with cholesterol or black pigment gallstones.
Gallbladder relaxation was measured in vitro using muscle strips and single muscle cells. Relaxation was expressed as percent inhibition of either basal active tension in strips or maximal cell contraction induced by diacylglycerol. The production of cyclic nucleotides was determined using a 125I-labeled radioimmunoassay kit.
Frequency-dependent relaxation evoked by electrical field stimulation was significantly lower in gallbladders with cholesterol stones than in gallbladders with pigment stones. Relaxation and adenosine 3',5'-cyclic monophosphate (cAMP) production induced by isoproterenol, vasoactive intestinal peptide, and forskolin were also significantly decreased in gallbladders with cholesterol stones. However, the relaxation in response to 8-bromo-cAMP, nitric oxide (NO), and the NO donor S-nitroso-N-acetylpenicillamine (SNAP), which circumvent plasma membrane receptors and directly activate intracellular mechanisms, was similar in gallbladders with cholesterol and pigment stones. Guanosine 3',5'-cyclic monophosphate production induced by NO and SNAP was also similar.
Human gallbladder muscle from specimens with cholesterol stones show an impaired relaxation and lower cAMP production compared with specimens with pigment stones. The muscle defect(s) responsible for this impairment seem to be in the plasma membranes.
患有胆固醇结石的胆囊对激动剂的收缩反应存在缺陷。本研究旨在调查患有胆固醇结石或黑色色素结石的人胆囊的肌肉松弛情况。
使用肌肉条和单个肌肉细胞在体外测量胆囊松弛。松弛程度以肌肉条基础主动张力或二酰甘油诱导的最大细胞收缩的抑制百分比表示。使用125I标记的放射免疫分析试剂盒测定环核苷酸的产生。
电场刺激引起的频率依赖性松弛在患有胆固醇结石的胆囊中显著低于患有色素结石的胆囊。异丙肾上腺素、血管活性肠肽和福斯高林诱导的松弛和腺苷3',5'-环磷酸（cAMP）产生在患有胆固醇结石的胆囊中也显著降低。然而，对8-溴-cAMP、一氧化氮（NO）和NO供体S-亚硝基-N-乙酰青霉胺（SNAP）的松弛反应，这些物质绕过质膜受体并直接激活细胞内机制，在患有胆固醇结石和色素结石的胆囊中相似。NO和SNAP诱导的鸟苷3',5'-环磷酸产生也相似。
与患有色素结石的标本相比，患有胆固醇结石标本的人胆囊肌肉显示出松弛受损和cAMP产生降低。导致这种损伤的肌肉缺陷似乎存在于质膜中。
