Endophenotype properties of niacin sensitivity as marker of impaired prostaglandin signalling in schizophrenia.

Background: Disruption of arachidonic acid pathways and prostaglandin signalling has been implicated in the pathophysiology of schizophrenia.

Aims: We intended to study prostaglandin signalling in groups of young schizophrenia patients, first-degree relatives, and healthy controls in order to assess effects of heritability on this biological marker-one important endophenotype criterion.

Method: Namely, we assessed intensity of methylnicotinate skin flushing using optical reflection spectroscopy.

Impaired working speed and executive functions as frontal lobe dysfunctions in young first-degree relatives of schizophrenic patients.

The aim of the investigation was to detect neuropsychological markers, such as sustained and selective attention and executive functions, which contribute to the vulnerability to schizophrenia especially in young persons. Performance was assessed in 32 siblings and children of schizophrenic patients and 32 matched controls using Wisconsin Card Sorting Test, Colour-Word-Interference-Test, Trail Making Test, and d2-Concentration-Test. The first-degree relatives showed certain impairments on all four tests, in particular, slower times on all time-limited tests.

The influence of age and gender on niacin skin test results - implications for the use as a biochemical marker in schizophrenia.

Investigation of abnormal skin response to niacin (vitamin B3) stimulation has gained increasing interest in schizophrenia research during last years. However, current efforts to implement niacin tests in routine diagnostics are jeopardised by wide inter-individual variations of skin response. We investigated age and gender as potential factors of influence on niacin sensitivity in 117 healthy subjects (63 male, 54 female).