Neuronal networks, derived from mouse embryonic frontal cortex (FC) tissue grown on microelectrode arrays, were used to investigate effects of gentamicin pretreatment on pharmacological response to the L-type calcium channel blocker, verapamil. Gentamicin is a broad spectrum antibiotic used to control bacterial contamination in cell culture. The addition of gentamicin directly to medium affects the pharmacological and morphological properties of the cells in culture. A reproducible dose response curve to verapamil from untreated cultures was established and the mean EC50 was calculated to be 1.5 ± 0.5 μM (n=10). 40 μM bicuculline was added to some cell cultures to stabilize activity and verapamil dose response curves were performed in presence of bicuculline, EC50 1.4 ± 0.1 μM (n=9). Statistical analysis showed no significant difference in verapamil EC50s values obtained in presence of bicuculline and hence the data was combined and a standard verapamil EC50 was calculated as 1.4 ± 0.13 μM (n=19). This EC50 was then used to compare verapamil EC50s obtained from neuronal cell cultures with chronic and acute exposures to gentamicin. FC cultures (21- 38 days old) were found to be stable in presence of 2300 μM gentamicin. The recommended concentration of gentamicin for contamination control is 5uL /1 ml medium (108 μM). At this concentration, the verapamil EC50 shifted from 1.4 ± 0.13 μM to 0.9 ± 0.2 μM. Given the limited data points and only two complete CRCs, statistical comparison was not feasible. However, there is a definite trend that shows sensitization of cells to verapamil in presence of gentamicin. The cultures exposed to 108 μM gentamicin for 5 days after seeding showed loss of adhesion and no data could be collected for pharmacological analysis. To conclude, acute gentamicin exposure of neuronal cell cultures causes increased sensitivity to verapamil and chronic or long term exposure to gentamicin may cause loss of adhesion of the cell culture by affecting the glial growth. The effect of chronic exposure to gentamicin on pharmacological responses to verapamil remains inconclusive.
| Identifer | oai:union.ndltd.org:unt.edu/info:ark/67531/metadc699991 |
| Date | 12 1900 |
| Creators | Sawant, Meera |
| Contributors | Gross, Guenter W., Fuchs, Jannon Lou, 1946-, Gopal, Kamashki |
| Publisher | University of North Texas |
| Source Sets | University of North Texas |
| Language | English |
| Detected Language | English |
| Type | Thesis or Dissertation |
| Format | ix, 70 pages : ǂb illustrations (some color), Text |
| Rights | Public, Sawant, Meera, Copyright, Copyright is held by the author, unless otherwise noted. All rights reserved. |
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