Basic fibroblast growth factor reduces lactic acid-induced neuronal injury in rat hippocampal neurons.
OBJECTIVE
To evaluate the long-term effects of lactic acidosis and to examine a potential neuroprotective role of basic fibroblast growth factor (bFGF) on hippocampal neurons.


METHODS
Long-term observation in a cell-culture study.


METHODS
University research laboratory.


METHODS
Adult, differentiated, primary rat hippocampal neurons.


METHODS
Neurons were exposed to medium acidified with 20 mM lactic acid, pH 6.2, for a 10-min period, and maintained untreated or in the presence of bFGF (500 pg/mL, 1 ng/mL, 10 ng/mL, 20 ng/mL) applied after exposure.


RESULTS
Viability was analyzed by a dye inclusion/enzyme activity test and morphology by phase contrast and immunofluorescence microscopy. [3H]Arachidonic acid (AA) release was measured by liquid scintillation spectrometry. All cultures appeared to be unchanged during the first days after exposure to lactic acidosis. Neurodegeneration became apparent within 3 days. Seven days after exposure, cell survival decreased to 60% in lactic acidosis-injured, untreated cultures. Morphologic damage appeared as a 50% reduction in axonal and 25% reduction in dendritic arborizations. AA release increased to four-fold enhanced levels relative to control values. bFGF (1, 20, and 10 ng/ mL) enhanced neuronal viability (p < .05), and 10 ng/mL bFGF induced a maximal increase in live cells to 80% of controls. Axonal arborizations increased to 50% and dendritic arborizations to 75% of controls after 10 ng/mL bFGF (p< .05). bFGF in a dose of 20 ng/ mL enhanced axonal branching to 40% and dendrites in number and branching to 50% of controls (p< .05). bFGF (500 pg/mL, and 1 and 10 ng/mL) decreased enhanced AA (p < .05), and 10 ng/mL bFGF maximally reduced increased AA to two-fold enhanced values relative to controls.


CONCLUSIONS
In vulnerable neurons, exposure to moderate lactic acidosis induces a process of cell injury with long latency. bFGF applied postinjury reduces the delayed neurodegeneration and may have neuroprotective efficacy in new therapeutic strategies to ischemia-induced cerebral injury.
Himmelseher
S
S
Department of Anesthesiology, University Hospital of Ulm, Germany.
Pfenninger
E
E
Georgieff
M
M
D000140:Acidosis, Lactic / Q000150:complications* / Q000188:drug therapy*; D000818:Animals; D002470:Cell Survival / Q000187:drug effects; D002478:Cells, Cultured; D004195:Disease Models, Animal; D004305:Dose-Response Relationship, Drug; D004353:Drug Evaluation, Preclinical; D005260:Female; D016222:Fibroblast Growth Factor 2 / Q000627:therapeutic use*; D006624:Hippocampus / Q000166:cytology / Q000293:injuries*; D009474:Neurons / Q000166:cytology; D018696:Neuroprotective Agents / Q000627:therapeutic use*; D011247:Pregnancy; D051381:Rats; D017207:Rats, Sprague-Dawley; D013997:Time Factors
D018696:Neuroprotective Agents; D016222:Fibroblast Growth Factor 2