title: High-molecular-weight forms of somatostatin are reduced in Alzheimer's disease and Down's syndrome.
abstract: Four molecular forms of somatostatin-like immunoreactivity (SOM-LI) are present in the human temporal cortex: SOM-14, SOM-28 and high-molecular-weight forms (HMW-SOM) of 7500 and 12,000 daltons. SOM-14 and HMW-SOM are depleted in cortical tissue from cases of pre-senile Alzheimer-type dementia (ATD), but there is a disproportionate reduction in HMW-SOM. In cases of Down's syndrome (DS) with the neuropathological and neurochemical changes of ATD, the total concentration of SOM-LI was similar to that in control cases and the proportions of molecular forms present were comparable. However, there was a significant reduction in the concentration of HMW-SOM. These results show that ATD and DS may share a common abnormality in the biosynthesis and/or post-translational processing of cortical SOM.
authors.forename: A R
authors.initials: AR
authors.lastname: Pierotti
authors.forename: A J
authors.initials: AJ
authors.lastname: Harmar
authors.forename: J
authors.initials: J
authors.lastname: Simpson
authors.forename: C M
authors.initials: CM
authors.lastname: Yates
mesh_terms: D000367:Age Factors; D000368:Aged; D000544:Alzheimer Disease / Q000378:metabolism*; D002795:Choline O-Acetyltransferase / Q000378:metabolism; D004314:Down Syndrome / Q000378:metabolism*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D008970:Molecular Weight; D010455:Peptides / Q000032:analysis; D013004:Somatostatin / Q000032:analysis*; D053561:Somatostatin-28; D013702:Temporal Lobe / Q000032:analysis* / Q000201:enzymology
chemical_list: D010455:Peptides; C029993:somatostatin-like peptides; D013004:Somatostatin; D053561:Somatostatin-28; D002795:Choline O-Acetyltransferase