Voltage-activated Na+ currents and their suppression by phorbol ester in clonal insulin-producing RINm5F cells.
The whole-cell configuration of the patch-clamp technique was applied on the clonal insulin-producing cell line RINm5). Thus attempts were made to characterize voltage-activated inward and outward membrane currents and to examine to what extent these were affected by both long-term and acute exposur...
| প্রধান লেখক: | , , |
|---|---|
| বিন্যাস: | Journal article |
| ভাষা: | English |
| প্রকাশিত: |
1986
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| _version_ | 1826275351669506048 |
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| author | Rorsman, P Arkhammar, P Berggren, P |
| author_facet | Rorsman, P Arkhammar, P Berggren, P |
| author_sort | Rorsman, P |
| collection | OXFORD |
| description | The whole-cell configuration of the patch-clamp technique was applied on the clonal insulin-producing cell line RINm5). Thus attempts were made to characterize voltage-activated inward and outward membrane currents and to examine to what extent these were affected by both long-term and acute exposure to the phorbol ester 12-O-tetradecanoylphorbol-13-acetate (TPA). Current responses to voltage-clamp steps up to -40 mV were small. A pulse to -28 mV evoked an inward current, and slowly activating outward currents developed at potentials above -20 mV. The inward current had a V-shaped current-voltage relationship, reaching a peak between -10 and 0 mV, whereas the outward current increased linearly at potentials beyond -20 mV. It was demonstrated that the inward currents are carried primarily by Ca2+ and Na+ and the outward current by K+. After long-term exposure to TPA, there was a suppression of Na+ currents in one-third of the cells, whereas the Ca2+ and K+ currents were unaffected. Acute exposure to the phorbol ester increased the Ca2+ currents with little effect on the Na+ currents. The extent to which the differences in effects on membrane currents initiated by respective acute and long-term exposure to TPA may reflect two separate mechanisms of protein kinase C activation, the latter related to regulation of differentiation of the RINm5F cells, merits further investigation. |
| first_indexed | 2024-03-06T22:57:24Z |
| format | Journal article |
| id | oxford-uuid:60e87ade-2efb-4075-93d3-a92cd3c9de06 |
| institution | University of Oxford |
| language | English |
| last_indexed | 2024-03-06T22:57:24Z |
| publishDate | 1986 |
| record_format | dspace |
| spelling | oxford-uuid:60e87ade-2efb-4075-93d3-a92cd3c9de062022-03-26T17:56:13ZVoltage-activated Na+ currents and their suppression by phorbol ester in clonal insulin-producing RINm5F cells.Journal articlehttp://purl.org/coar/resource_type/c_dcae04bcuuid:60e87ade-2efb-4075-93d3-a92cd3c9de06EnglishSymplectic Elements at Oxford1986Rorsman, PArkhammar, PBerggren, PThe whole-cell configuration of the patch-clamp technique was applied on the clonal insulin-producing cell line RINm5). Thus attempts were made to characterize voltage-activated inward and outward membrane currents and to examine to what extent these were affected by both long-term and acute exposure to the phorbol ester 12-O-tetradecanoylphorbol-13-acetate (TPA). Current responses to voltage-clamp steps up to -40 mV were small. A pulse to -28 mV evoked an inward current, and slowly activating outward currents developed at potentials above -20 mV. The inward current had a V-shaped current-voltage relationship, reaching a peak between -10 and 0 mV, whereas the outward current increased linearly at potentials beyond -20 mV. It was demonstrated that the inward currents are carried primarily by Ca2+ and Na+ and the outward current by K+. After long-term exposure to TPA, there was a suppression of Na+ currents in one-third of the cells, whereas the Ca2+ and K+ currents were unaffected. Acute exposure to the phorbol ester increased the Ca2+ currents with little effect on the Na+ currents. The extent to which the differences in effects on membrane currents initiated by respective acute and long-term exposure to TPA may reflect two separate mechanisms of protein kinase C activation, the latter related to regulation of differentiation of the RINm5F cells, merits further investigation. |
| spellingShingle | Rorsman, P Arkhammar, P Berggren, P Voltage-activated Na+ currents and their suppression by phorbol ester in clonal insulin-producing RINm5F cells. |
| title | Voltage-activated Na+ currents and their suppression by phorbol ester in clonal insulin-producing RINm5F cells. |
| title_full | Voltage-activated Na+ currents and their suppression by phorbol ester in clonal insulin-producing RINm5F cells. |
| title_fullStr | Voltage-activated Na+ currents and their suppression by phorbol ester in clonal insulin-producing RINm5F cells. |
| title_full_unstemmed | Voltage-activated Na+ currents and their suppression by phorbol ester in clonal insulin-producing RINm5F cells. |
| title_short | Voltage-activated Na+ currents and their suppression by phorbol ester in clonal insulin-producing RINm5F cells. |
| title_sort | voltage activated na currents and their suppression by phorbol ester in clonal insulin producing rinm5f cells |
| work_keys_str_mv | AT rorsmanp voltageactivatednacurrentsandtheirsuppressionbyphorbolesterinclonalinsulinproducingrinm5fcells AT arkhammarp voltageactivatednacurrentsandtheirsuppressionbyphorbolesterinclonalinsulinproducingrinm5fcells AT berggrenp voltageactivatednacurrentsandtheirsuppressionbyphorbolesterinclonalinsulinproducingrinm5fcells |