Neonatal and adult patterns of lectin binding to rat small intestinal microvillus membranes.

To investigate postnatal developmental changes of rat small intestinal microvillus membrane (MVM) sugar components, binding studies were done using peanut agglutinin (PNA) and soybean agglutinin (SBA). MVM were prepared from rats of different ages (new-borns to 12 weeks). The Airfuge method was used for separation of unbound material. Characteristics of sugar ligand specificity were different for PNA and SBA, although D(+)galactose was used as an inhibitor for both lectins. Concentration curves and Scatchard plots showed partial saturation of total binding, and at least two groups of MVM ligands. Differences in lectin binding between newborn and adult MVM were opposite for PNA and SBA (newborns bound more PNA, but less SBA). During the first few postnatal weeks in rats, SBA binding changed early, and PNA binding exhibited an intermediate change, not related to weaning. Changes in MVM glycoproteins shown by lectin binding appear to be part of a complex postnatal maturational process in rats, involving different biochemical, functional, and biophysical membrane characteristics.