We decided to study the effect of glucose deprivation on collagen metabolism in MCF7 cells. The incorporation of [3H]-proline into collagenase-sensitive and hydroxyproline-containing proteins was used as an index of collagen synthesis, whereas pulse—chase technique was employed to evaluate the degradation of newly synthesized proteins. The MCF7 cells incubated in high glucose medium synthesized detectable amounts of collagenous proteins. Most of them were found in the cell layer. The shortage of glucose resulted in about 30% reduction in collagen synthesis. The pulse—chase experiments demonstrated that proportionally less collagen was degraded in cultures incubated in low-glucose than in high-glucose media.