Support of cultured hepatocytes by a laminin-rich gel. Evidence for a functionally significant subendothelial matrix in normal rat liver.
The subendothelial space of normal rat liver contains the constituent proteins of a basal lamina, as judged by immunohistochemical study of tissue sections. However, it is unknown whether these proteins constitute a complex with effects on hepatocellular function. We have examined this question, using normal rat hepatocytes cultured on substrata of matrix proteins as a model of the interaction between cells and basal lamina in vivo. In cultures on a type I collagen substratum, albumin secretion decreased progressively after 2 d. By contrast, when cells were cultured on a laminin-rich gel matrix, albumin secretion was stable for at least 3 wk; other functions and ultrastructural morphology were similarly maintained. None of the individual matrix proteins effectively substituted for the gel matrix, suggesting that full support of hepatocellular function requires a complex of matrix proteins. We speculate that a cause of hepatocellular dysfunction in acute inflammation is disruption of this matrix and alteration of its interaction with the hepatocyte plasma membrane.
D000418:Albumins / Q000378:metabolism; D000818:Animals; D001485:Basement Membrane / Q000502:physiology; D002462:Cell Membrane / Q000502:physiology; D002478:Cells, Cultured; D003094:Collagen / Q000502:physiology; D003470:Culture Media; D004727:Endothelium / Q000502:physiology; D005109:Extracellular Matrix / Q000502:physiology*; D005455:Fluorescent Antibody Technique; D005782:Gels; D007797:Laminin / Q000502:physiology*; D008099:Liver / Q000502:physiology* / Q000648:ultrastructure; D008854:Microscopy, Electron; D011506:Proteins / Q000502:physiology; D051381:Rats; D011919:Rats, Inbred Strains
D000418:Albumins; D003470:Culture Media; D005782:Gels; D007797:Laminin; D011506:Proteins; D003094:Collagen