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- Sombers, L A, et al.
(author)
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High Osmolarity and L-DOPA Augment Release via the Fusion Pore in PC12 Cells
- 2007
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In: Chemphyschem. - : Wiley. - 1439-4235 .- 1439-7641. ; 8:17, s. 2471-2477
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Journal article (peer-reviewed)abstract
- We have amperometrically measured dopamine release from rat pheochromocytoma cells (PC12 cells) in high osmolarity conditions with and without L-3,4-dihydroxyphenylalanine (L-DOPA) treatment. We observe an increase in the number of release events displaying a prespike feature or foot when the cells are stimulated in high osmolarity saline. We also see an increase in foot area and duration when cells are stimulated in high osmolarity saline, or high osmolarity saline subsequent to incubation with the dopamine precursor L-DOPA in isotonic saline, which serves to increase the vesicle size. The data suggest that membrane biophysics are an important component in defining the rate, duration and amount of neurotransmitter release via the fusion pore.
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| 2. |
- Sombers, L A, et al.
(author)
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Multicore Vesicles: Hyperosmolarity and l-DOPA Induce Homotypic Fusion of Dense Core Vesicles
- 2007
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In: Cellular and Molecular Neurobiology. - 0272-4340 .- 1573-6830. ; 27:5, s. 681-685
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Journal article (peer-reviewed)abstract
- Aim A fraction of vesicles in cells treated with hypertonic solution exhibit multiple dense cores and this is enhanced by treatment with l-3,4–dihydroxyphenylalanine (l-DOPA). These cells were examined to determine if the multicore vesicles are the product of endocytosis or homotypic fusion. Methods Electron microscopy was used to determine the number of multicore vesicles and amperometry was used to examine if the multicore vesicles are a competent fraction of the readily releasable pool. Results In this study, we observed that a substantial portion (15.3%) of large dense core vesicles in PC12 cells contained multiple cores in hypertonic saline loaded with l-DOPA, and amperometric measurements show a bimodal distribution of quantal sizes in treated cells. Conclusions The results suggest that the multicored vesicles are formed from homotypic fusion of LCDVs prior to exocytosis.
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