| Autor: |
F S, Gravina, P, Jobling, K P, Kerr, R B, de Oliveira, H C, Parkington, D F, van Helden |
| Rok vydání: |
2011 |
| Předmět: |
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| Zdroj: |
Experimental physiology. 96(9) |
| ISSN: |
1469-445X |
| Popis: |
Oxytocin is known to play important roles in uterine contractions, mediated at least in part by increasing intracellular Ca(2+) concentration ([Ca(2+)](i)), through enhancing extracellular Ca(2+) entry and Ca(2+) release from the sarcoplasmic reticulum, processes that are intimately linked with mitochondria. This study examined the effects of oxytocin on mitochondrial function. This was achieved by measuring the ratiometric JC-1 fluorescence signal in isolated myometrial cells, which provides a relative measure of the mitochondrial membrane potential (ψ(m)), and also by loading the cells with Oregon Green BAPTA-AM to examine changes in [Ca(2+)](i). Oxytocin (1 nm) depolarized the ψ(m) to 73.8 ± 3.7% of the control value (P 0.05; perfused for 11 min) and also caused a transient increase in [Ca(2+)](i). The depolarization of mitochondrial membrane potential was effectively reversed by 2-aminoethoxydiphenyl borate, nifedipine, Ca(2+)-free solution or oligomycin, with the ratiometric JC-1 fluorescence signal becoming no different from the control value in all cases (i.e. P 0.05). The reduction in ψ(m) is likely to occur at least in part through the oxytocin-induced increase in [Ca(2+)](i), causing enhanced mitochondrial uptake of Ca(2+) and resultant dissipation of the mitochondrial electrochemical gradient. ATP synthase is also stimulated, which would further contribute to a decrease in ψ(m). |
| Databáze: |
OpenAIRE |
| Externí odkaz: |
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