An evaluation of human neurophysin production in Alzheimer's disease: Preliminary observations

Abstract

The concentrations of human neurophysins in the cerebrospinal fluid (CSF) of nine patients with Alzheimer's disease: Preliminary observations. (AD), and one patients with Pick's disease, were determined using specific radioimmunoassays (RIAs). Concentrations of vasopressin and oxytocin were also measured. Values were compared with those from 20 age-matched mentally normal individuals who were being treated for back pain. CSF levels of vasopressin-associated human neurophysin (VP-HNP) and oxytocin-associated human neurophysin (OT-HNP) in patients with AD (22 ± 4 fmol/ml and 104 ± 17 fmol/ml) were only 42% and 58% of those in the control subjects ( p < 0.0001, p < 0.0004). Vasopressin levels for these patients (3.6 ± 0.4 fmol/ml) were also significantly reduced to 51% of controls ( p < 0.007) and oxytocin levels were marginally ( p = 0.092) reduced to 70% of controls. Because neurophysins and neuropeptides are generelated products of vasopressin-neurons and oxytocin-neurons, the data indicate that these neurons are functionally impaired in patients with AD. Plasma neurophysin values suggest this impairment is confined to neurons with centrally-directed axons. Data from the one patient with Pick's disease demonstrates that reduced CSF levels of neurophysins and hormones is not confined to Alzheimer-type dementia.