Figure 2.

Time kinetics of CFU-F and CFU-OB production by murine bone marrow cells cultured in type I collagen gels. (a) Marrow cell cultures were established in type I collagen gels (10 × 10⁶ cells per gel), and CFU-F and CFU-OB content was assessed either immediately (day 0) or after culture for 2, 7, 11, or 16 days. The data shown represent the mean (± SEM) number of CFU-Fs and CFU-OBs per gel. Preliminary experiments established that the number of CFU-Fs and CFU-OBs in the initial marrow isolate not put into the gel was indistinguishable from the 0 time values (not shown). Error bars are not visible because the symbols are larger than the error bars. Data were analyzed using mixed-effect ANOVA as described in Methods. Significant (P < 0.01) increases in progenitor number versus day 0 were detected at all time points, except for CFU-OBs at day 2. CFU-OB number at day 16 was significantly less than at day 11 (P < 0.05). (b) Marrow cell cultures were established in type I collagen gels as in a without (vehicle) or with 5 μg/ml 5-FU. Progenitor number was then determined after 2 or 5 days of culture. The number of progenitors in the initial isolate (day 0) is expressed per 10 × 10⁶ marrow cells. ^AP < 0.05 treatment versus vehicle.