Surface properties of adult rat hepatocytes: Mechanism of increased concanavalin A-induced agglutinability following papain digestion

Adult rat hepatocytes, obtained by collagenase perfusion, exhibit a 4-fold increase in concanavalin A (ConA)-induced agglutination following papain digestion. Several parameters which may be responsible for this altered ConA-induced agglutination have been examined, namely the amount and topography of surface-bound ConA and the morphology of the cell-surface. Binding studies using [ 125I]ConA demonstrated that the amount of surface-bound ConA was the same for papain-digested and incubated control hepatocytes. Surface binding of ferritin-conjugated ConA revealed that both the incubated control and papain-digested hepatocytes possessed a similar clustered distribution of surface-bound ConA. The most significant difference between the incubated control and papain-digested hepatocytes was an alteration in the surface morphology of papain-digested cells. Cells incubated in the absence of papain maintained the surface morphology of the non-incubated hepatocyte, i.e., a surface characterized by numerous microvilli; whereas the papain-digested cells exhibited a smooth surface. These results indicate that the surface morphology of the papain-treated hepatocytes allows greater areas of membrane contact, thereby increasing their agglutinability by ConA.