[Endogenous nociceptin level in ischemic stroke: connection to serotonin system]. 
Particular role of the heptadecapeptide nociceptin (orphanin FQ), the endogenous agonist of the NOP receptor, has been widely demonstrated in the regulation of pain sensation and anxiety-related behavior.  In our best knowledge this is the first study reporting plasma nociceptin levels in 26 acute stroke and 6 transiens ischemic attack (TIA) patients.  We have found significantly elevated plasma nociceptin levels in all the three groups of patients studied (stroke influencing the carotis or the lacunar region and TIA).  We suggest that elevated plasma nociceptin level is the consequence of stroke as in the group of patients recovered from previous stroke was found similar the control value.  Plasma serotonin level was found non-significantly decreased in patients with stroke influencing the lacunar region and TIA patients.  However the plasma 5-hydroxy-indoleacetic acid (5HIAA) levels were found significantly elevated in patient groups with stroke influencing both the carotis and the lacunar regions.  Data may serve as further evidence for the serotonergic dysregulation in stroke.