Protective Action of Mucopolysaccharides on Dog Kidney Cell Line MDCK in Meniscus-Gradient Culture

Summary

The effect of heparin, chondroitin sulfate, hyaluronic acid, and N-acetylneuraminic acid on the growth of Maden Darby canine kidney cells in meniscus-gradient culture was investigated.

Cell suspensions (200,000 cells/ml of 30% calf serum in Eagle's minimal essential medium) were inoculated into small Leighton tubes containing 11- × 35-mm coverslips, and the tubes were incubated in horizontal position. After 1 or 2 days, when the cells had grown to confluency, they were fed with 2 ml of medium containing either heparin, chondroitin sulfate, hyaluronic acid, or N-acetylneuraminic acid solution (0.05% of the substance added to the medium). Then all tubes were placed in a vertical position. The medium was replaced two or three times weekly.

After 5 days, marked differences were observed between the control and the treated cultures in cell viability and attachment. The cells degenerated and detached in the bottom area of the control tubes, leaving a narrow viable zone 5 mm wide just below the surface of the medium. This degeneration was, however, prevented for as long as 2 weeks when the mucopolysaccharides were added to the medium. In the treated groups the cells were viable even to a depth of 14 mm, and mitotic figures were observed at the bottom of the tube. In the heparin-treated group many blisters could be observed.

This result indicates that mucopolysaccharides may play a role in protecting and sustaining the viability and coordinated transport function of Maden Darby canine kidney cells in a microenvironment that otherwise is not compatible with viability.