Normal pattern of labeling of cerebral cortical corticotropin-releasing factor (CRF) receptors in alzheimer's disease: Evidence from chemical cross-linking studies

Recent data have demonstrated that in Alzheimer's disease, the concentrations of corticotropin-releasing factor (CRF) were reduced and that there were reciprocal increases in CRF receptors in affected cerebrocortical areas. In order to determine whether the increases in CRF receptors in Alzheimer's disease were due to altered molecular composition of the binding protein, we compared the labeling pattern of 125I-Tyr 0ovine CRF in temporal neocortex of Alzheimer's patients and age-matched controls using chemical cross-linking techniques. A similar pattern of 125I-Tyr 0ovine CBF labeling was seen in Alzheimer's and control brains, with the major CRF binding protein corresponding to an apparent molecular weight of 58,000 Da. These data indicate that the increased CRF receptor population in cerebral cortex in Alzheimer's disease comprises bona fide CRF receptor binding subunits with no apparent change in the molecular structure.