Adenosine release and uptake in cerebellar granule ...
Description
Citation
| Title | Adenosine release and uptake in cerebellar granule neurons both occur via an equilibrative nucleoside carrier that is modulated by G proteins |
| Author(s) | M. Sweeney-Nixon |
| Journal | Journal of Neurochemistry |
| Date | 1996 |
| Volume | 67 |
| Issue | 1 |
| Start page | 81 |
| End page | 88 |
| Abstract | These is debate about the mechanisms mediating adenosine release from neurons. In this study, the release of adenosine evoked by depolarizing cultured cerebellar granule neurons with 50 mM K+ was inhibited by 49 +/- 7% in Ca2+-free medium. The remaining release was blocked by dipyridamole (IC50 = 6.4 x 10(-8) M) and nitrobenzylthioinosine (IC50 = 3.6 x 10(-8) M), inhibitors of adenosine uptake. Ca2+-dependent release was reduced by 78 +/- 9% following a 21-h pretreatment of the cells with pertussis toxin, which ADP-ribosylates Gi/Go G proteins, thereby preventing their dissociation. The nucleoside transporter-mediated component of K+-induced adenosine release also was inhibited by 62 +/- 8% by pertussis toxin and was potentiated by 78 +/- 11% following cholera toxin treatment, which permanently activates Gs. Uptake of [3H]adenosine into cultured cerebellar granule neurons over a 10-min period was not dependent on extracellular Na+ but was reduced by dipyridamole (IC50 = 3.2 x 10(-8) M) and nitrobenzylthioinosine (IC50 = 2.6 x 10(-8) M). Thus, adenosine uptake likely occurs via the same transporter mediating Ca2+-independent adenosine release. Adenosine uptake was potentiated by cholera toxin pretreatment (152 +/- 15% of control), but pertussis toxin had no statistically significant effect. It is possible that Gs, Gi/Go, or free Gbetagamma dimer modulate the equilibrative, inhibitor-sensitive nucleoside carrier to enhance adenosine transport. |
| ISSN | 0022-3042 |
| Use/Reproduction | Contact Author |
Using APA 6th Edition citation style.
[Page generation failure. The bibliography processor requires a browser with Javascript enabled.]
Times viewed: 113
