The cells of the bovine outflow system in tissue culture.

Meshwork cells from the bovine outflow system were grown in culture and their growth characteristics and behaviour in vitro reported. The cells were studied by inverted phase microscopy and time-lapse cinephotomicrography. It was found that plating efficiency was highest for third and seventh passage cells. These cells reached confluence within 2 weeks when plated out at 7.5 X 10(3) cells cm-2 in a conventional culture medium containing 10% serum. Third passage cells were studied in greatest detail. These cells exhibited postconfluence contact inhibition of division. By 2 weeks postconfluence the division rate decreased 10-fold to a level of less than six divisions per thousand cells per day. The contact inhibition was not overcome by increasing the serum content of the medium. On the other hand, a 30-fold increased division rate could be produced after scratching the culture flask. Postconfluent contact-inhibited cultures were considered to be a better reflection of the behaviour and activities of meshwork cells in vivo than cultures which retain a high level of division.