- Title
- Oxytocin depolarizes mitochondria in isolated myometrial cells
- Creator
- Gravina, F. S.; Jobling, P.; Kerr, K. P.; de Oliveira, R. B.; Parkington, H. C.; van Helden , D. F.
- Relation
- Experimental Physiology Vol. 96, Issue 9, p. 949-956
- Publisher Link
- http://dx.doi.org/10.1113/expphysiol.2011.058388
- Publisher
- Wiley-Blackwell Publishing
- Resource Type
- journal article
- Date
- 2011
- Description
- Oxytocin is known to play important roles in uterine contractions, mediated at least in part by increasing intracellular Ca2+ concentration ([Ca2+]i), through enhancing extracellular Ca2+ entry and Ca2+ 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 (ψm), and also by loading the cells with Oregon Green BAPTA-AM to examine changes in [Ca2+]i. Oxytocin (1 nm) depolarized the ψm to 73.8 ± 3.7% of the control value (P < 0.05; perfused for 11 min) and also caused a transient increase in [Ca2+]i. The depolarization of mitochondrial membrane potential was effectively reversed by 2-aminoethoxydiphenyl borate, nifedipine, Ca2+-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 ψm is likely to occur at least in part through the oxytocin-induced increase in [Ca2+]i, causing enhanced mitochondrial uptake of Ca2+ and resultant dissipation of the mitochondrial electrochemical gradient. ATP synthase is also stimulated, which would further contribute to a decrease in ψm.
- Subject
- oxytocin; uterine contractions; mitochondria; myometrial cells
- Identifier
- http://hdl.handle.net/1959.13/936493
- Identifier
- uon:12328
- Identifier
- ISSN:1469-445X
- Language
- eng
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