SDS-polyacrylamide gel electrophoretic patterns of human parotid saliva treated with polyvinylpyrrolidone-iodine in vitro.

In the intraoral application of polyvinylpyrrolidone-iodine (PVP-I) as an antimicrobial agent, a color fading phenomenon is observed that might be caused by the binding of iodine with saliva. We have investigated the binding of iodine with saliva as iodine binding factor (IBF). The presence and characteristics of the IBF were investigated in parotid saliva stimulated by sour lemon drops, unstimulated parotid saliva, and whole saliva. A high level of the binding ability with iodine was observed in stimulated parotid saliva with the treatment of PVP-I compared with the unstimulated, but there were no significant differences in the amounts of total proteins between the stimulated and unstimulated. Electrophoretic patterns of saliva treated with PVP-I and untreated were examined to detect the IBF. The protein band of SDS-polyacrylamide gel electrophoresis near M.W. 60,000 of stimulated parotid saliva disappeared after treatment of PVP-I. This evidence indicates that the color fading phenomenon of PVP-I is associated with a polypeptide level in saliva.