C-fos expression in vivo in human lymphocytes in response to stress.

1. Blood samples from which lymphocytes were isolated were obtained from patients immediately prior to cardiac catheterization (stress period) and again four to five hours later (post-stress period). Blood was also taken from a normal non-stressed control subject. 2. Lymphocyte c-fos mRNA was reverse transcribed followed by strand synthesis of DNA template and amplification using PCR with sequence-specific primers. 3. C-fos mRNA was detectable in lymphocytes from the normal control subject and in patient samples obtained immediately prior to cardiac catheterization, but was not detectable in patient samples obtained four to five hours later. 4. Possible mechanisms for these findings include a stress-related decrease in lymphocyte proliferation and differentiation or a negative feedback effect of the c-fos protein on transcription of the c-fos gene. 5. These findings suggest that it may be possible to monitor peripheral early gene expression as a marker for a variety of conditions including stress, psychiatric disorders and the response to psychotropic drugs.