Fig. 1.

Cellular uptake of [¹⁴C]glycine and biosynthesis of ¹⁴C-labeled heme precursors and metabolites from [¹⁴C]glycine in primary cultures of olfactory receptor neurons. Primary cultures of olfactory receptor neurons were prepared from neonatal rats as described previously and used for this experiment on culture day 3. Cultures in the well plates were incubated with [2-¹⁴C]glycine for 6 hr. At indicated time intervals, cellular uptake of [2-¹⁴C]glycine (A) and the ¹⁴C-radioactivities incorporated into [¹⁴C]ALA (B), [¹⁴C]heme (C), and ¹⁴CO (D) were measured as described in Materials and Methods. Data are presented as the mean of two to four independent experimental determinations.