Biochemical and autoradiographical evidence that anterior mandibular displacement in the young growing rat does not stimulate cell proliferation or matrix formation at the mandibular condyle

Abstract

A removable bite plate was used to induce forward mandibular displacement in four-week-old rats for 10h/day for 1, 3, 7, 11 and 14 days. The animals were killed and the condylar explants pulsed in vitro for 6 h with either [3H]-thymidine or [3H]-proline or 35SO42-. The specific activity of radio-isotope incorporation was expresed as dis/min per μg DNA, dis/min per mg protein and dis/min per μg sulphated glycosaminoglycans (GAG). [3H]-thymidine autoradiography was also used in a 14-day experiment to establish a radioactive index (labelled cells per 1000 cells counted) for the anterior, middle and posterior regions of the condyle. There was no significant alteration in either cell proliferatio..