The low density lipoprotein receptor-related protein (LRP) is a multifunctional endocytic receptor with the ability to bind and endocytose several structurally and functionally distinct ligands. The 39 kDa receptor-associated protein (RAP) is an endoplasmic reticulum (ER) resident protein, which is believed to function intracellularly as a molecular chaperone for LRP and to regulate its ligand binding activity along the secretory pathway. Mouse heparin binding protein-44 (HBP-44) is a homologue of human RAP. Using a recombinant form of HBP-44 expressed in Escherichia coli cells as a highly specific ligand for LRP, we demonstrated that HBP-44 coated on cell culture plates mediates the cell-substratum adhesion of mouse 3T3 fibroblasts in a dose-dependent manner, with 50% attachment at the concentration of 0.2 micrograms/ml. Ligand blot analysis with HBP-44 of whole cell extracts and the materials precipitated by anti-LRP antibodies revealed that the receptor for HBP-44 on NIH/3T3 cells was LRP. The results suggest that LRP serves as a cell adhesion receptor in some cells.

3T3 Cells↗

PubMedDate not supplied

Studies on visual evoked cortical response by liquid crystal phase difference haploscope: amblyopia and/or strabismus.

Visual evoked cortical potentials induced by alternate stimulation of checkerboard pattern with the use of liquid crystal phase difference haploscope were investigated. The synchronization ratio of brain response was determined both in the group of normal binocularity and in the group with binocularity defect. The synchronization ratio of the group of normal binocularity (N = 30) is 100% at 1 Hz x 2, 98.5% +/- 3.9% at 5 Hz x 2, and 83.7% +/- 15.8% at 10 Hz x 2. On the other hand, in the group with binocularity defect, strabismus without amblyopia shows a reduction of the ratio only at the frequency of 10 Hz x 2. Anisometropic amblyopia shows a significant reduction of the ratio at 10 Hz x 2 and strabismus with amblyopia shows a remarkable reduction at 5 Hz x 2 and 10 Hz x 2. As for strabismus with or without latent binocularity, the latter cases show a significant reduction of the synchronization ratio. The reduction of synchronization ratio of VECP seems to have some relationship to the binocularity.

Adolescent↗

PubMedDate not supplied

Myocardial infarction induces expression of midkine, a heparin-binding growth factor with reparative activity.

We examined midkine (MK) expression in the rat heart upon experimental myocardial infarction. Immunohistochemical staining revealed, 6 hours after ligation of the left anterior descending coronary artery, strong MK immunoreactivity in myocytes and endothelial cells of a non-infarcted cardiac region. The myocytes of the infarcted cardiac region destined for death showed only a little immunoreactivity. Northern blot analysis suggested that the increased immunoreactivity was due to increased MK synthesis. The induced MK expression is likely to mimic the expression during embryogenesis: MK was strong lye-expressed in the myocytes of embryonic heart, and the expression decreased during embryogenesis.

Animals↗