Naumenko N V, Uzinskaya K V, Shakirzyanova A V, Urazaev A Kh, Zefirov A L
Kazan State Medical University, Tatarstan, Russia.
Bull Exp Biol Med. 2009 May;147(5):583-6. doi: 10.1007/s10517-009-0575-2.
Exogenous adenosine triphosphoric acid produces a biphasic effect on the resting membrane potential of muscle fibers in rat diaphragm. Depolarization of the sarcolemma observed 10 min after application of adenosine triphosphoric acid results from activation of Na(+)/K(+)/2Cl(-) cotransport. The increase in chloride cotransport is related to activation of postsynaptic P2Y receptors and protein kinase C. Repolarization of the membrane develops 40 min after treatment with adenosine triphosphoric acid and after 50 min the resting membrane potential almost returns the control level. This increase in the resting membrane potential of the sarcolemma is probably associated with activation of the Na(+)/K(+) pump and increase in membrane permeability for chlorine ions in response to long-term activity of Cl(-) cotransport. Thus, adenosine triphosphoric acid co-secreted with acetylcholine in the neuromuscular synapse probably plays a role in the regulation resting membrane potential and cell volume of muscle fibers.
外源性三磷酸腺苷对大鼠膈肌肌纤维的静息膜电位产生双相作用。应用三磷酸腺苷10分钟后观察到的肌膜去极化是由Na(+)/K(+)/2Cl(-)协同转运的激活引起的。氯离子协同转运的增加与突触后P2Y受体和蛋白激酶C的激活有关。用三磷酸腺苷处理40分钟后膜发生复极化，50分钟后静息膜电位几乎恢复到对照水平。肌膜静息膜电位的这种增加可能与Na(+)/K(+)泵的激活以及氯离子协同转运的长期活动导致的氯离子膜通透性增加有关。因此，在神经肌肉突触中与乙酰胆碱共同分泌的三磷酸腺苷可能在调节肌纤维的静息膜电位和细胞体积中起作用。
