The rapid intermembraneous transfer of retinoids

The intermembraneous rates of retinoid (all-$\text{trans}$-retinol(al), 11-$\text{cis}$-retinol and all-$\text{trans}$-retinol palmitate) transfer from vesicle to vesicle and vesicle to erythrocyte were studied. The rates of transfer of the retinols(al) were exceedingly rapid. The rates of transfer of the retinols(al) from egg phophatidyl choline based SUV's to bovine erythrocytes had a half-time of approximately 1–2 min. The vesicle to vesicle transfer rate was too rapid to measure by conventional techniques. By contrast, all-$\text{trans}$-retinol palmitate did not undergo transfer at an appreciable rate.