The effect of orally-administered retinoid on lectin binding in guinea pig keratinocytes

Retinoids influence proliferation and differentiation of epithelial cells. The present paper was designed to examine the change of lectin binding in isolated keratinocytes from retinoid-treated guinea pigs. Aromatic retinoid, etretinate, in peanut oil (5 mg/kg/day) was given orally for a period of 14 days. Skin samples were obtained from animals on days 1, 3, 7, and 14 after beginning the administration. Free keratinocytes were obtained by treatment with EDTA and trypsin. They were separated into 3 fractions by centrifugation on a continuous colloidal silica (Percoll) density gradient. The cells in each fraction were stained by biotinyl lectins and avidin-FITC, and the fluorescence intensity was measured by cytofluorometry. The lectins used were Concanavalin A (Con A), soybean agglutinin (SBA), peanut agglutinin (PNA), Dolichos biflorus agglutinin (DBA), and Ricinus communis agglutinin (RCA). The PNA-binding was diminished in both the intermediate and lower density fractions at 7 and 14 days. The binding of SBA was reduced in all fractions from 1 to 7 days. With Con A, RCA and DBA, no changes in intensity were found.