Patients with Alzheimer's disease show an increased content of 15 Kdalton somatostatin precursor and a lowered level of tetradecapeptide in their cerebrospinal fluid.
The relative proportions of both somatostatin-14 and its precursors somatostatin-28 and the 15 Kdalton prosomatostatin were evaluated by radioimmunoassay in the cerebrospinal fluid of patients with Alzheimer's disease. It was observed that the patients have a lowered content in the tetradecapeptide somatostatin while they exhibit a significant increase in unprocessed 15 Kda precursor. These results indicate that these patients possess impaired processing mechanisms which may be responsible for the lowered content in mature somatostatin-14. These observations may provide a valuable test for the ante-mortem diagnosis of the disease. They are discussed in connection with others suggesting that Alzheimer's patients may be selectively altered in their somatostatinergic neurones of their cerebral cortex (Morrison et al. (1985) Nature 314, 90-92. Roberts et al. (1985) Nature 314, 92-94).
D000368:Aged; D000544:Alzheimer Disease / Q000134:cerebrospinal fluid*; D006801:Humans; D008875:Middle Aged; D011498:Protein Precursors / Q000134:cerebrospinal fluid*; D011863:Radioimmunoassay; D013004:Somatostatin / Q000134:cerebrospinal fluid*
D011498:Protein Precursors; D013004:Somatostatin; C028456:prosomatostatin