乙酰胆碱诱导钙离子释放增强大鼠胰腺腺泡呼吸的机制。

Mechanisms of respiration intensification of rat pancreatic acini upon carbachol-induced Ca(2+) release.

机构信息

Biology faculty, Department of Human and Animal Physiology Hrushevsky, Ivan Franko National university of Lviv, Lviv, Ukraine.

出版信息

Acta Physiol (Oxf). 2013 Aug;208(4):387-99. doi: 10.1111/apha.12119. Epub 2013 Jun 11.

DOI:10.1111/apha.12119

PMID:23692873

Abstract

AIM

Acetylcholine as one of the main secretagogues modulates mitochondrial functions in acinar pancreacytes, presumably due to increase in ATP hydrolysis or Ca(2+) transport into mitochondria. The aim of this work was to investigate the mechanisms of carbachol (CCh) action on respiration and oxidative phosphorylation of isolated pancreatic acini.

METHODS

Respiration of intact or permeabilized rat pancreatic acini was studied at 37 °C using a Clark oxygen electrode.

RESULTS

Respiration rate of isolated acini in rest was 0.27 ± 0.01 nmol O2 s(-1) 10(-6) cells. Addition of 10 μM CCh into respiration chamber evoked biphasic stimulation of respiration. Rapid increase of respiration by 20.1% lasted for approx. 1 min, followed by decrease to level by 11.5% higher than control. Addition of 1 μm CCh caused monophasic increase by 11.5%. Preincubation (5 min) with 1 or 10 μm CCh elevated respiration rate by 12.5 or 11.2% respectively. FCCP prevented the effect of CCh. Preincubation with 1 (but not 10) μm CCh increased FCCP-uncoupled respiration rate. Thapsigargin slightly elevated respiration, but ryanodine did not. Application of 2-aminoethoxydiphenyl borate or ruthenium red prevented the effects of CCh on respiration, while oligomycin abolished them. Preincubation with 1 μm CCh prior to cell permeabilization increased respiration rate at pyruvate+malate oxidation, but not at succinate oxidation. In contrast, preincubation with 10 μm CCh decreased pyruvate+malate oxidation.

CONCLUSION

Medium CCh dose (1 μm) intensifies respiration and oxidative phosphorylation of acinar pancreacytes by feedforward mechanism via Ca(2+) transport into mitochondria and activation of Ca(2+) /ADP-sensitive mitochondrial dehydrogenases. Prolonged action of high CCh dose (10 μm) might impair mitochondrial functions.

摘要

目的

乙酰胆碱作为主要的分泌调节剂之一，调节胰腺腺泡细胞的线粒体功能，推测是由于 ATP 水解或 Ca(2+)向线粒体的转运增加所致。本工作旨在研究卡巴胆碱（CCh）对分离的胰腺腺泡呼吸和氧化磷酸化的作用机制。

方法

在 37°C 下使用克拉克氧电极研究完整或通透化的大鼠胰腺腺泡的呼吸。

结果

在休息时，分离的胰腺腺泡的呼吸速率为 0.27±0.01 nmol O2 s(-1) 10(-6) 细胞。向呼吸室中加入 10 μM CCh 会引起呼吸的双相刺激。呼吸的快速增加持续约 1 分钟，增加了 20.1%，然后下降到比对照高 11.5%的水平。加入 1 μm CCh 引起 11.5%的单相增加。用 1 或 10 μM CCh 预孵育（5 分钟）分别使呼吸率升高 12.5%或 11.2%。FCCP 可防止 CCh 的作用。用 1（但不是 10）μM CCh 预孵育可增加 FCCP 解偶联的呼吸率。他普西格雷略微增加呼吸，但雷尼替丁没有。应用 2-氨基乙氧基二苯硼酸盐或钌红可防止 CCh 对呼吸的作用，而寡霉素则消除了这些作用。细胞通透化前用 1 μM CCh 预孵育可增加丙酮酸+苹果酸氧化时的呼吸率，但不增加琥珀酸氧化时的呼吸率。相比之下，用 10 μM CCh 预孵育可降低丙酮酸+苹果酸的氧化。