EXCITATION - CONTRACTION COUPLING OF GALLBLADDER MUSCLE

胆囊肌肉的兴奋-收缩耦合

• 批准号: 3081010
• 负责人: HENRY PAUL PARKMAN
• 金额: $ 7.56万
• 依托单位: TEMPLE UNIV OF THE COMMONWEALTH
• 依托单位国家: 美国
• 财政年份: 1993
• 资助国家: 美国
• 起止时间: 1993-01-01 至 1997-12-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/3081010
• 关键词: acetylcholine; calcium channel; calcium flux; cats; cholecystokinin; cholelithiasis; disease /disorder model; fluorescent dye /probe; gallbladder; human tissue; membrane potentials; muscle contraction; neural transmission; neurohormones; neurotransmitters; potassium; smooth muscle; voltage /patch clamp

The objective of this research proposal is to investigate the mechanisms of excitation-contraction coupling in the gallbladder smooth muscle and in doing so, prepare the applicant for a long term career as an independent investigator. Excitation-contraction coupling of gallbladder smooth muscle is particularly important because abnormal gallbladder contractility may play a primary pathophysiologic role in the formation of gallstones. Investigation of excitation-contraction coupling in feline gallbladder smooth muscle will provide a background for studies in human gallbladder smooth muscle in gallstone disease. The specific aims of this project are: 1) to characterize the utilization of intracellular and extracellular calcium sources in excitation-contraction coupling in isolated gallbladder myocytes stimulated by three agonists - acetylcholine, cholecystokinin, and potassium; 2) to determine the transmembrane electrical properties of gallbladder smooth muscle in muscle strips under basal conditions and to determine the effects of classical neurotransmitters and hormones on electromechanical coupling by evaluating the voltage-tension relationships of graded concentrations of extracellular potassium, acetylcholine, and cholecystokinin; 3) to evaluate the effects of endogenous neurotransmitters on intracellular electrical activity and muscle tension of gallbladder smooth muscle using electric field stimulation to activate intrinsic enteric nerves of the gallbladder; and 4) to characterize the excitation-contraction coupling abnormalities in human gallbladder smooth muscle from patients with gallstones. Several sophisticated research techniques will be employed in the conduct of this project: simultaneous intracellular electrical and isometric muscle tension recordings will be performed to investigate the electromechanical coupling of gallbladder smooth muscle; freshly dispersed isolated gallbladder myocytes will be used to measure cell shortening; cytosolic calcium concentrations will be evaluated using the calcium-sensitive fluorescent dye indo-1; and cell membrane calcium channels will be characterized using the whole cell patch clamp technique. In the process of elucidating the mechanisms of gallbladder excitation-contraction coupling, the relationship between cell membrane potential, calcium utilization, membrane calcium currents and gallbladder smooth muscle contraction will be better understood. The candidate is a physician-scientist who is determined to develop a career committed to the study of gastrointestinal motility. To achieve this goal, the candidate will continue to work with and learn from two respected basic scientists in gastrointestinal smooth muscle and cardiac muscle physiology. Interaction with these investigators will provide a stimulating and productive environment, so that the candidate can conduct productive research and position himself to compete successfully for independent extramural funding in the future.

这项研究计划的目的是探讨其作用机制。 胆囊肌的兴奋-收缩偶联和 在这样做的过程中，为申请者的长期职业生涯做好准备 独立调查员。胆囊性兴奋收缩偶联 平滑肌特别重要，因为异常的胆囊症 收缩能力可能在形成过程中起主要的病理生理作用。 胆结石。激发-收缩耦合作用的研究 猫的胆囊肌将为研究提供背景 在人的胆囊壁平滑肌中，有胆石症。具体的 本项目的目标是：1)描述利用 兴奋收缩中的细胞内和细胞外钙源 三种激动剂刺激的胆囊肌细胞偶联 乙酰胆碱、缩胆囊素和钾；2)测定 胆囊壁平滑肌跨膜电特性的研究 在基础条件下的肌肉条和确定的效果 机电耦合中的经典神经递质和激素 通过评估分级浓度的电压-张力关系 细胞外钾、乙酰胆碱和缩胆囊素；3)至 评价内源性神经递质对细胞内的影响 胆囊肌的电活动和肌张力 电场刺激激活大鼠肠内神经 4)确定兴奋-收缩偶联的特征 慢性胆囊炎患者的人胆囊壁平滑肌异常 胆结石。将使用几种复杂的研究技术。 在这个项目的实施过程中：同时进行细胞内电信号 并进行等长肌肉张力记录，以研究 胆囊肌的机电耦合；新鲜的 将使用分散的分离的胆囊肌细胞来测量细胞 缩短；细胞内钙浓度将使用 钙敏感荧光染料Indo-1和细胞膜钙 将使用全细胞膜片钳来表征通道 技术。在阐明胆囊病发病机制的过程中 兴奋-收缩偶联，细胞膜之间的关系 电位、钙利用、膜钙电流与胆囊壁 人们将更好地理解平滑肌肉收缩。 候选人是一位内科科学家，他决心开发一种 致力于胃肠动力的研究。要实现 为了实现这一目标，候选人将继续与两人合作并向他们学习 受人尊敬的胃肠道平滑肌和心脏基础科学家 肌肉生理学。与这些调查人员的互动将提供一个 激励和富有成效的环境，使应聘者能够进行 富有成效的研究和定位使自己能够成功竞争 未来独立的校外资金。