Antidepressants and Anti-Inflammatory Drugs Differentially Reduce the Release of NGF and BDNF from Rat Platelets

Introduction: Platelets store serotonin and brain-derived neurotrophic factor (BDNF) as well as amyloid precursor protein and nerve growth factor (NGF), thus platelets are of special interest in depression and Alzheimer's disease, respectively. Both diseases are associated with inflammation and release of NGF or BDNF from platelets may play a potent role. Methods: Platelets were isolated from adult Sprague-Dawley rats and were incubated with anti-inflammatory drugs (ibuprofen and indomethacin) and antidepressants (citalopram, paroxetine and sertraline) (final concentration: 0.3 mu M) with or without 2 mM calcium chloride. The release of NGF and BDNF was analyzed in comparison to serotonin release from rat platelets after 10 or 60 min. Results: Spontaneous release of serotonin and BDNF was approximately 10-15 % of total serotonin or BDNF content in platelets, but nearly all NGF was released within 10 min. All antidepressants increased the serotonin release from rat platelets. NGF release was reduced by sertraline, paroxetine and ibuprofen, but only when calcium was present, except for sertraline after 10 min. BDNF release was only reduced by ibuprofen when calcium was added. Conclusion: We conclude that antidepressants and anti-inflammatory drugs differentially influence the NGF and BDNF release, in a time-, dose- and calcium-specific pattern.